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CC 2014-02-25_08.k. Adoption of Ordinance Regarding StormwaterMEMORANDUM TO: CITY COUNCIL FROM: TERESA MCCLISH, COMMUNITY DEVELOPMENT DIRECTOR BY: MIKE LINN, ASSISTANT CITY ENGINEER SUBJECT: CONSIDERATION OF AN ORDINANCE OF THE CITY COUNCIL OF THE CITY OF ARROYO GRANDE REPEALING CHAPTER 13.24 OF THE ARROYO GRANDE MUNICIPAL CODE AND ADOPTING A NEW CHAPTER 13.24 GOVERNING GRADING, ADDING A NEW CHAPTER 25 TO TITLE 13 REGULATING ILLEGAL DISCHARGES AND ILLICIT CONNECTIONS, AND ADDING NEW SECTIONS TO TITLE 16, CHAPTERS 08 AND 68 REGARDING DESIGN REQUIREMENTS FOR POST CONSTRUCTION STORMWATER COMPLIANCE DATE: FEBRUARY 25, 2014 RECOMMENDATION: It is recommended that the City Council adopt an ordinance repealing Chapter 13.24 of the Arroyo Grande Municipal Code and adopting and new Chapter 13.24 governing grading, adding a new Chapter 24 to Title 13 regulating illegal discharges and illicit connections, and adding new sections to Title 16, Chapters 08 and 68 regarding design requirements for post construction stormwater compliance. IMPACT ON FINANCIAL AND PERSONNEL RESOURCES: Ongoing monitoring and inspection of post construction requirements will require additional staff time. Specific costs and funding sources have not yet been identified. BACKGROUND: The City must adopt regulations in order to comply with the requirements of the Federal Clean Water Act, the implementing regulations for the National Pollutant Discharge Elimination System (NPDES), and the California Porter-Cologne Water Quality Control Act. These requirements provide for the regulation and reduction of pollutants discharged to waters of the State and United States by extending NPDES requirements to storm water and urban runoff discharges to arid from municipal storm drain systems. The City implements these requirements through the Storm Water Management Program (SWMP) that was originally approved by City Council Resolution 3708 in 2003. The SWMP requires programs and regulations to manage storm water discharges within the City and has been updated periodically to stay current with State Item 8.k. - Page 1 CITY COUNCIL CONSIDERATION OF AN ORDINANCE REPEALING CHAPTER 13.24 OF THE ARROYO GRANDE MUNICIPAL CODE AND ADOPTING A NEW CHAPTER 13.24 GOVERNING GRADING, ADDING A. NEW SECTION TO TITLE 16, CHAPTER 68 REGARDING DESIGN REQUIREMENTS FOR POST CONSTRUCTION STORM WATER COMPLIANCE, AND ADDING A NEW CHAPTER 25 TO TITLE 13 REGULATING ILLEGAL DISCHARGES AND ILLICIT CONNECTIONS. FEBRUARY 25, 2014 PAGE 2 OF 4 requirements. The SWMP has since been revised in accordance with State requirements and is now referred to as the Storm Water Guidance Document (SWGD). The SWGD is a requirement of the California Environmental Protection Agency State Water Resources Control Board Phase II Small Municipal Separate Storm Sewer System (MS4) Permit. The SWGD includes a series of steps to ensure compliance, including requirements to update regulations in the City's Municipal Code for construction activities, post construction management of storm water, illegal discharges and illicit connections. The Planning Commission recommended adoption of the ordinance on February 4, 2014. The Council approved the Design Requirements for Post Construction Stormwater Compliance and introduced the ordinance on February 11, 2014. ANALYSIS OF ISSUES: Generally, the proposed ordinance includes three parts: 1) a revised grading ordinance in Chapter 13.24 that incorporate provisions for stormwater, as well as providing an overall update for the ordinances last updated in 2003; 2) a new Chapter 13.25 to include regulations for illegal discharges and illicit connections; and 3) provisions in Code Sections 13.24, 16.08 and 16.68 to require compliance with the City's design requirements for post construction storm water discharges by approving the guidelines and incorporating them by reference into the Municipal Code. Chapter 13.24 Excavation. Grading. Erosion and Sediment Control The grading ordinance establishes standards to regulate the disturbance of earth during construction within the City limits, including excavations, filling and compaction, stormwater runoff, and environmental protection. Notable updates to the new chapter include: • Requirements for erosion and sediment controls, soil stabilization, dewatering, source controls, pollution prevention measures and prohibited discharges; • Mandatory minimum construction site Best Management Practices (BMPs); • Development of Storm Water Pollution Prevention plans (SWPPPs) for defined projects; • Inspection and compliance; and • Enforcement mechanisms. Chapter 13.25 Illegal Discharges and Illicit Connections The ordinance creates an entirely new chapter to address the following: • Prohibition of non-stormwater discharges to the storm drain system; Item 8.k. - Page 2 CITY COUNCIL CONSIDERATION OF AN ORDINANCE REPEALING CHAPTER 13.24 OF THE ARROYO GRANDE MUNICIPAL CODE AND ADOPTING A NEW CHAPTER 13.24 GOVERNING GRADING, ADDING A NEW SECTION TO TITLE 16, CHAPTER 68 REGARDING DESIGN REQUIREMENTS FOR POST CONSTRUCTION STORM WATER COMPLIANCE, AND ADDING A NEW CHAPTER 25 TO TITLE 13 REGULATING ILLEGAL DISCHARGES AND ILLICIT CONNECTIONS. FEBRUARY 25, 2014 PAGE30F4 • Regulation of the contribution of pollutants to groundwater, Arroyo Grande Cr~ek or Meadow Creek by stormwater discharges; • Prohibition of illicit connections and illegal discharges to the storm drain system; • Elimination of stormwater connections which are not documented in plans, maps or equivalent records; • Spill prevention; and • Establishment of legal authority to carry out all inspection, surveillance, monitoring, and enforcement procedures necessary to ensure compliance. Sections 16.08 and 16.68 Post Construction Stormwater Requirements The California Regional Water Quality Control Board for the Central Coast Region (Water Board) adopted Post Construction Requirements in July 2013 and issued Water Quality Order No. 2013-0001-DWQ to incorporate post-construction controls for MS4 storm water discharges, establishing March 6, 2014 as the date of implementation. Staff has developed design requirements for post construction storm water compliance that address the following: • Performance requirements, based on the development project area, addressing site design, water quality, and runoff retention; • Low Impact Development (LID) design standards; • Hydromodification measures; • Post-construction best management practice condition assessment; • Planning and development review process; and • Alternative compliance. ALTERNATIVES: The following alternatives are provided for Council consideration: Adopt the proposed ordinance; Amend and re-introduce the proposed ordinance; Do not introduce the proposed ordinance; and Provide direction to staff. ADVANTAGES: The City will implement requirements for stormwater management per the Storm Water Guidance Manual and comply with State requirements. Item 8.k. - Page 3 CITY COUNCIL CONSIDERATION OF AN ORDINANCE REPEALING CHAPTER 13.24 OF THE ARROYO GRANDE MUNICIPAL CODE AND ADOPTING A NEW CHAPTER 13.24 GOVERNING GRADING, ADDING A NEW SECTION TO TITLE 16, CHAPTER 68 REGARDING DESIGN REQUIREMENTS FOR POST CONSTRUCTION STORM WATER COMPLIANCE, AND ADDING A NEW CHAPTER 25 TO TITLE 13 REGULA TING ILLEGAL DISCHARGES AND ILLICIT CONNECTIONS. FEBRUARY 25, 2014 PAGE40F4 DISADVANTAGES: Some requirements, primarily the post construction requirements, will place burdens and increase costs for developers, as well as require additional staff resources to monitor, inspect and ensure compliance. However, the City is regulated under the State Water Resources Control Board NPDES General Permit for MS4 dischargers and is mandated to adopt and implement these requirements. ENVIRONMENTAL REVIEW: In accordance with the California Environmental Quality Act (CEQA) Guidelines, staff has determined that the draft ordinance is exempt per Section 15308 of the Guidelines which governs actions by regulato,ry agencies for the protection of the environment. PUBLIC NOTIFICATION AND COMMENTS: A summary of the ordinance was published in The Tribune on Tuesday, February 18, 2014 pursuant to State Law. The agenda was posted in front of City Hall on Thursday, February 20, 2014 and both the agenda and staff report were posted on the City's website on Friday, February 21, 2014. Item 8.k. - Page 4 ORDINANCE NO. AN ORDINANCE OF THE CITY COUNCIL OF THE CITY OF ARROYO GRANDE REPEALING CHAPTER 13.24 OF THE ARROYO GRANDE MUNICIPAL CODE AND ADOPTING A NEW CHAPTER 13.24 GOVERNING GRADING, ADDING A NEW CHAPTER 25 TO TITLE 13 REGULATING ILLEGAL DISCHARGES AND ILLICIT CONNECTIONS, AND ADDING NEW SECTIONS TO TITLE 16, CHAPTERS 08 AND 68 REGARDING DESIGN REQUIREMENTS FOR POST CONSTRUCTION STORMWATER COMPLIANCE WHEREAS, the Federal Clean Water Act, National Pollutant Discharge Elimination System ("NPDES") and the California Porter Cologne Water Quality Control Act provide for the regulation and reduction of pollutants discharged to waters of the State and United States by extending NPDES requirements to storm water and urban runoff discharges to and from the storm drain system; and WHEREAS, Central Coast municipalities are regulated under the State Water Resources Control Board NPDES General Permit ("General Permit") for the Discharge of Storm Water from Small Municipal Separate Storm Sewer Systems ("MS4s"), Order No. 2013-0001-DWQ, adopted by the State Water Resources Control Board on February 5, 2013; and WHEREAS, Order No. 2013-001-DWQ requires the City to address storm water runoff from development and redevelopment projects through post-construction storm water management requirements; and WHEREAS, in order to comply with the General Permit and in order to update and improve the City's excavation, grading, erosion and sediment control, sections of the Arroyo Grand Municipal Code require revision ("proposed amendment"); and WHEREAS, public notice has been given in the time and manner required by State law and City Code; and WHEREAS, the Planning Commission of the City of Arroyo Grande reviewed and considered the proposed amendments at a Public Hearing on February 4, 2014; and WHEREAS, at its meeting of February 11, 2014, the City Council duly considered all evidence, including public testimony from interested parties and the evaluation and recommendations by the Planning Commission; and WHEREAS, the proposed amendment is consistent with the General Plan; and Item 8.k. - Page 5 ORDINANCE NO. PAGE2 WHEREAS, the proposed amendment is internally consistent with other applicable provisions of the Arroyo Grande Municipal Code; and WHEREAS, this Ordinance is consistent with protection of the public interest, health, safety and welfare of the City. This Ordinance is hereby found to be categorically exempt from environmental review pursuant to CEQA guidelines Section 15308, Actions by Regulatory Agencies for Protection of the Environment. NOW, THEREFORE BE IT ORDAINED by the City Council of the City of Arroyo Grande as follows: SECTION 1. Recitals. The above recitals are true and correct and are incorporated herein by this reference. SECTION 2. Title 13, Chapter 24 of the Arroyo Grande Municipal Code is repealed in its entirety and replaced with a new Chapter 24 of Title 13, entitled "EXCAVATION, GRADING, EROSION AND SEDIMENT CONTROL," as set forth in the attached Exhibit A, which is incorporated herein by this reference. SECTION 3. Title 13 of the Arroyo Grande Municipal Code is amended to add a new Chapter 25, entitled "ILLICIT DISCHARGES AND ILLICIT CONNECTIONS," as set forth in the attached Exhibit B, which is incorporated herein by this reference. SECTION 4. Title 16, Chapter 8, Section 010, of the Arroyo Grande Municipal Code is amended to add a new Subsection T, referencing a new document a copy of which is attached to this Ordinance and incorporated herein by this reference as Exhibit C, for incorporation by reference into the Arroyo Grande Municipal Code, as follows: T. Design Requirements for Post Construction Stormwater Compliance, as the same may be amended from time to time. SECTION 5. Title 16, Chapter 68, Section 030 of the Arroyo Grande Municipal Code is amended to add a new Subsection D, to read as follows: D. Design Requirements for Post Construction Stormwater Compliance. All new development or redevelopment projects that create and/or replace greater than or equal to 2,500 square feet of impervious surface (collectively over the entire project site) must comply with the Design Requirements ~or Post Construction Stormwater Compliance adopted by the City and incorporated herein by this reference. SECTION 6. Severability. If any section, subsection, subdivision, paragraph, sentence, or clause of this Ordinance or any part thereof is for any reason held to be unlawful, such decision shall not affect the validity of the remaining portion of this Ordinance or any part Item 8.k. - Page 6 ORDINANCE NO. PAGE3 thereof. The City Council hereby declares that it would have passed each section, subsection, subdivision, paragraph, sentence, or clause thereof, irrespective of the fact that any one or more section, subsection, subdivision, paragraph, sentence, or clause be declared unconstitutional. SECTION 7. Ordinance Summary. A summary of this Ordinance shall be published in a newspaper and circulated in the City of Arroyo Grande at least five (5) days prior to the City Council meeting at which the proposed Ordinance is to be adopted. A certified copy of the full text of the proposed Ordinance shall be posted in the office of the City Clerk. Within fifteen (15) days after adoption of the Ordinance, the summary with the names of those City Council Members voting for and against the Ordinance shall be published again, and the City Clerk shall post a certified copy of the full text of such adopted Ordinance. SECTION 8. Effective Date. This Ordinance shall take effect thirty (30) days after its adoption. On motion of Council Member following roll call vote to wit: AYES: NOES: ABSENT: , seconded by Council Member The foregoing Ordinance was adopted this_ day of ______ , 2014. , and on the Item 8.k. - Page 7 ORDINANCE NO. PAGE4 TONY FERRARA, MAYOR ATTEST: KELLY WETMORE, CITY CLERK APPROVED AS TO CONTENT: STEVEN ADAMS, CITY MANAGER APPROVED AS TO FORM: TIMOTHY J. CARMEL, CITY ATTORNEY Item 8.k. - Page 8 EXHIBIT A Chapter 13.24 EXCAVATION, GRADING, EROSION AND SEDIMENT CONTROL Sections: 13.24.010 Purpose. 13.24.020 Definitions. 13.24.030 Scope. 13.24.040 Grading Permit Exemptions. 13.24.050 Grading Permit Requirements. 13.24.060 Grading Plan Requirements 13.24.070 Design Standards for Grading. 13.24.080 Temporary Stockpiles 13.24.090 Design Standards for Drainage. 13.24.100 Drainage Plan Requirements 13.24.110 Stormwater Management 13.24.120 Erosion and Sediment Control Plan Requirements. 13.24.130 Stormwater Pollution Prevention Plan (SWPP) Requirements 13.24.140 Design standards for Stormwater Pollution Prevention Plan. 13.24.150 Inspection and Compliance. 13.24.160 Enforcement. 13.24.170 Hazards. 13.24.180 Fees. 13.24.190 Bonds and securities. 13.24.010 Purpose. The purpose of this chapter is to establish standards to safeguard the public health, safety and general welfare; minimize erosion and sedimentation; minimize fugitive dust emissions; reduce the harmful effects of stormwater runoff; encourage groundwater recharge; protect fish and wildlife; reduce hazards to life and property; reduce drainage problems from new development; prevent environmental damage to public and private property; and to otherwise protect the natural environment. This Chapter addresses compliance with the National Pollutant Discharge Elimination System (NPDES) Phase II stormwater regulations and sets forth local stormwater requirements, to avoid pollution of watercourses with sediments or other pollutants generated on or caused by surface runoff on or across construction sites. 13.24.020 Definitions. When used in this chapter, the definitions listed hereunder shall have the meanings as specified in this section: "Accelerated erosion" means rapid erosion caused by human-induced alteration of the vegetation, land surface topography or runoff patterns. Evidence of accelerated erosion is indicated by exposed soils, active gullies, tills, sediment deposits, or slope failures caused by human activities, including grazing promoted by human activities. -~~-- Item 8.k. - Page 9 "Access and building envelope" means a delineated area within which all land disturbances for construction of access and/or building will be confined. "Agricultural Operations" or "Agricultural Production" means any operation occurring on a ranch or farm directly related to the growing of crops, or raising of fowls or animals for the primary purpose of making a profit or for a livelihood. "Applicant" means any person, corporation, partnership, association of any type, public agency or any other legal entity who submits an application to the building official for a permit pursuant to this chapter. "Approval" means a written engineering or geological opinion concerning the progress and completion of the work. "As-grade" is the surface conditions extent on completion of grading. "Bedrock" means in-place, solid rock. "Bench" means a relatively level step excavated into earth material on which fill is to be placed. "Best Management Practices (BMPs)" are practices, means, methods, measures, devices, structures, vegetative plantings and/or a combination thereof designed to safely control erosion and sediment so that construction wastes or contaminants from construction materials, tools and equipment are prevented from entering the storm drain system. "Borrow'' means earth material acquired from an off-site or other on-site location for use in grading on a site. "Clearing" means the removal or vegetation and debris down to bare soil by any method. "Civil engineer" means a professional engineer in the branch of civil engineering holding a valid certificate of registration issued by the State of California. "Civil engineering" means the application of the knowledge of the forces of nature, principles of mechanics and the properties of materials to the evaluation, design and construction of civil works. "Compaction" means the densification of earth and solids or a fill by mechanical means. "Development permit" means a permit issued for new land use activities, building, grading, land clearing, subdivision, planned unit development, and/or other project approval process administered by the city. "Director of Community Development" means that person charged with the responsibility of directing all phases of the planning, building, engineering, and the enforcement of all state statutes and city laws pertaining to his or her office, or his or her duly authorized representative. "Director of Public Works" means that person charged the responsibility of coordinating all phases of administration determining policy and procedures and directing the· work of subordinates within the various divisions encompassed with the Department of Public Works. "Drainage course" mean a well defined, natural or man-made channel which conveys storm water runoff either year-round or intermittently. "Earth material" means any rock, natural soil or fill and/or any combination thereof. Item 8.k. - Page 10 "Engineering geologist" means a person holding a valid registration as an engineering geologist and certified in the specialty of engineering geology issued by the State of California under provisions of the Geologist Act of the Business and Professions Code. "Engineering geology'' means the application of geologic knowledge and principles in the investigation and evaluation of naturally occurring rock and soil for use in the design of civil works. "Erosion" means the wearing away of the ground surface by the actions of water, wind, ice, gravity, or a combination thereof. "Erosion control specialist" means a person who is registered in the state or by a professional society and is capable of preparing erosion and sediment control plans. In the event it is the opinion of the building official such plan requires design of civil works, the specialist must be licensed as a civil engineer in the state. "Erosion hazards" means the susceptibility of a site to erode based on soils, condition and steepness of a slope, rock type, vegetation, and other site factors. "Erosion, sediment and runoff control planning" means the application of the knowledge of erosion and sediment control principles and practices in the investigation and evaluation for use in the design of civil works. "Erosion sediment and runoff control practices" means methods, measures, devices, structures, vegetative plantings and/or a combination thereof designed to control erosion and sediment; to safely contain and/or dispose of storm water runoff; and to stabilize soils and slopes. "Excavation" means the mechanical removal of earth materials. "Fill" means the deposit of permitted materials by artificial means. "Grade" means the vertical location of the ground surface. "Existing grade" means the grade prior to grading. "Rough grade" means an approximate elevation of the ground surface conforming to the approved plan. "Finished grade" means the final grade or surface conditions of the site which conforms to the approved plan. "Grading" means any excavation, filling, leveling, or combination thereof (excludes stripping and/or clearing), all new earthwork that involves one or more of the following activities: excavations, cuts, fills, leveling, dams, reservoirs, levees, impoundments, diking, dredging, borrow pits, stockpiling, compaction of fill, or removal of vegetation. Cultivation activities, including disking, harrowing, raking or chiseling, planting, plowing, seeding, or other tilling are not considered grading and are not regulated under this ordinance. "High priority construction site" are those project that are subject to the Construction General Permit, and projects not subject to the Construction General Permit that meet one or more of the following circumstances: discharges directly drain to a creek, involves site work on slopes of 20 percent or greater, involves hillside development on slopes steeper than 10 percent, involves more than 20,000 sf of land disturbance, include excavation of 100 CY of materials or more, and/or that have grading located within a geologic study or flood hazard areas. n Item 8.k. - Page 11 "Key" means a designed, compacted fill placed in a trench excavated in earth material beneath the toe of a proposed fill slope. "Land disturbance" means clearing, stripping, grading or other manipulation of the natural terrain by manual and/or mechanical means. "Net impervious area" means the total post-project impervious surface area (including both new and replacement surface area), minus any reduction in total imperviousness from the pre-project to the post- project condition. Net Impervious Area = (New and Replaced Impervious Area) -(Reduced Impervious Area Credit), where Reduced Impervious Area Credit is the total pre-project to post-project reduction in impervious area, if any. "NPDES" means National Pollution Discharge Elimination System, the national program for controlling discharges under the Federal Clean Water Act. "One hundred (100) year storm" means there is a 1 in 100 or 1% chance that a storm will reach this intensity in any given year "Owner" means the person or persons shown in the county recorder's office as owner of property. "Permittee" means the owner, contractor, or any person undertaking land disturbance activities upon a site pursuant to a permit granted by the building official authorizing performance of a specified activity. "Runoff' means the passage of surface water over ground surface. "Sediment" means eroded earth material that is carried and/or deposited by water, wind, gravity or ice and is a major source of water pollution. "Site" means a lot or parcel of land or contiguous combination thereof, where land disturbance including erosion control, clearing, grading, or construction are performed, permitted, or proposed. "Slope" means an inclined ground surface, the inclination of which is expressed as a ratio of horizontal distance to vertical distance. "Soil" means naturally occurring superficial deposits overlying bedrock. "Soil Engineer" means a civil engineer experienced and knowledgeable in the practice of soil engineering. "Soil engineering" means the application of the principles of soil mechanics in the investigation, evaluation and design of civil works involving the use of earth materials and the inspection and testing of the construction thereof. "Stabilization" means the prevention of erosion to exposed soil. "Start of construction" means the first land-disturbing activity associated with a construction project. "Storm Water Control Plan" is a plan, developed by the Regulated Project applicant, detailing how the project will achieve the applicable Post-Construction Stormwater Management Requirements (for both onsite and offsite systems). "Storm Water Pollution Prevention Plan" is a plan that provides for erosion control using the specific best management practices to control sediment and erosion on a construction site during and after construction. Item 8.k. - Page 12 "Stream" means any water course as designated by a solid line or dash and three dots symbol shown on the largest scale of United States Geological Survey map most recently published. "Stormwater Control Measures" is any stormwater management measures integrated into project designs that emphasize protection of watershed processes through replication of pre development runoff patterns {rate, volume, duration). Physical control measures include, but are not limited to, bioretention/rain gardens, permeable pavements, roof downspout controls, dispersion, soil quality and depth, minimal excavation foundations, vegetated roofs, and water use. Design control measures include but are not limited to conserving and protecting the function of existing natural areas, maintaining or creating riparian buffers, using onsite natural drainage features, directing runoff from impervious surfaces toward pervious areas, and distributing physical control measures to maximize infiltration, filtration, storage, evaporation, and transpiration of stormwater before it becomes runoff. "Temporary Stockpiles" means soil stockpiled upon a land area for future site development or for temporary storage for a maximum period of eighteen months. "10-year storm" means there is a 1 in 10 or 10% chance that a storm will reach this intensity in any given year ''Terrace" means a relatively level step constructed in the face of a graded slope surface for drainage and maintenance purposes. ''Topsoil" means loose, pliable, organic and fertile earth materials on top of a soil profile, usually the "A" horizons. "Treatment Control Measure" is any engineered system designed to remove pollutants by simple gravity · settling of particulate pollutants, filtration, biological uptake, media absorption or any other physical, biological, or chemical process. "Water Pollution Control Plan {WPCP)" is a plan that accompanies erosion and sedimentation control plans, unless exempted by the Director or the Public Works Director. Best Management Practices {BMPs) shall be in compliance with CASQA handbook or equivalent. A project SWPPP also can serve as the WPCP. "Unstable soil" means soil which is not competent to support other soil or fill, to support structures, or to satisfactorily perform the other functioning for which the soil is intended. 13.24.030 Scope. This chapter sets forth standards, including the incorporation of Best Management Practices {BMPs),to control excavation, grading, erosion and sediment; requires control of all existing and potential conditions of accelerated erosion; establishes administrative procedures for issuance of permits; and provides for approval of plans and inspections during construction and maintenance. All activities subject to subdivision map requirements and/or building permits shall meet these standards. This Chapter also provides for the approval of plans and inspection of grading construction and BMPs. In the event of any conflict between the provisions of this Chapter and state law, the more restrictive requirement shall apply. 13.24.040 Grading Permit Exemptions Note: While the activities under this section are exempted from a grading permit for the purposes of this City's ordinance, the owner and/or applicant should understand that permits may be required by other regulatory agencies, including, but not limited to, the California Department of Fish and Wildlife , Regional Water Quality Control Board, Army Corps of Engineers, U.S. Fish and Wildlife Service, or the California Department of Forestry (Cal Fire). Additionally, grading projects involving work within a State or County right-of-way may require encroachment permit approval. Item 8.k. - Page 13 No person shall do any land disturbance work without first obtaining a permit from the Director of Community Development. A grading permit shall be obtained where grading is to occur meeting the definition set forth in Section 13.24.050 (Grading). Activities that do not constitute grading as defined in this Chapter, or are exempt from grading permits, may be subject to other applicable sections in this ordinance. This includes requirements, such as preparation and approval of an erosion and sedimentation control plan, drainage plan, and/or stormwater pollution prevention plan. In granting any permit in compliance with this Chapter, the Director of Community Development and, where provided, the Director of Public Works, may impose conditions as necessary. These conditions may include requiring a licensed contractor to perform the work or a licensed professional (e.g. civil engineer, geotechnical engineer, etc.) to prepare plans or technical reports in order to prevent creation of a nuisance or a hazard to public health, public safety, or public or private property, or to assure conformity to the City's General Plan. The following grading does not require a grading permit. Exempt grading activities must employ appropriate sedimentation and erosion control measures: a. Isolated area: grading in an isolated, self-contained area if there is no danger to private or public property; b. Emergency work: work necessary to preserve life or property; provided, however, that when emergency work is performed under this section, the person performing it shall report the pertinent facts relating to the work to the Director of Community Development within fifteen (15) days after commencement of the work and shall thereafter obtain a permit pursuant to Section 13.24.050 and perform such work as may be determined by the Director of Community Development to be reasonably necessary to correct any erosion or conditions with a potential to cause erosion as a result of the emergency work; c. Excavation: an excavation which does not exceed fifty (50) cubic yards and is less than one foot in depth, does not create a cut slope higher than five feet and steeper than two to one (2:1 ); d. Fill: a fill containing only permitted materials less than one-foot deep, placed on natural terrain slope flatter than five to one (5:1 ), and does not exceed fifty (50) cubic yards on any one site, including stockpiles, does not alter or obstruct a drainage course, will not be used for structural support or roadways and the area graded or filled does not exceed eleven thousand (11,000) square feet (one-quarter acre). This exemption shall not apply to a fill within a riparian zone; e. Basements and footings: an excavation below finished grade for basements and footings of a building, retaining wall or other structure authorized by a valid building permit. This shall not exempt any fill except as provided under subsection D of this section, made with the material from such excavation or exempt any excavation having an unsupported height greater than five feet after the completion of such structures; f. Cemeteries: cemetery graves; excavation, or fill within a property used or to be used for cemetery purposes is exempt. Grading that is intended to support structures or that will affect natural drainage patterns do not fall under this exemption; g. Refuse disposal: refuse, individual and/or community sewage disposal sites controlled pursuant to other regulations; h. Wells and utilities: excavations for wells, tunnels or utilities; i. Exploratory investigations: excavations under the direction of a soils engineer or engineering geologist where such excavation is to be returned to the original condition within forty-five (45) days after the start of work; j. Clearing an area of eleven thousand (11,000) square feet (one-quarter acre) or less on five percent slopes or less; Item 8.k. - Page 14 k. Agricultural: normal routine farming activities necessary to manage land, crops and/or animals for food production; I. Mining, quarrying, excavating, processing, stockpiling of rock, sand, gravel, aggregate or clay where established and provided for by law, provided such operations are conditioned by other permits to preclude discharge of sediments offsite and provided such operations do not affect the lateral support or increase the stresses or pressure upon any adjacent or contiguous property; m. Grading activities shall receive all necessary approvals from other City, state, or federal agencies, regardless of whether the activity is exempt under this Chapter; n. Activities exempted under this section are still required to incorporate all reasonable measures to ensure against erosion and sedimentation both during and after such activities. In all cases, any grading activities which could result in a hazardous condition are not exempt from grading permit requirements. A hazardous condition exists when activities create a hazard to life and limb, endanger property, adversely affect the safety, use or stability of a public right-of-way or drainage channel, or create a significant environmental impact. 13.24.050 Grading Permit Requirements A grading permit is required in any of the following cases, unless the project qualifies for an exemption or constitutes agricultural grading as set forth in Section 13.24.040: 1. 50 cubic yards. The amount of material, measured cumulatively (adding together all proposed earthwork) for any of the above mentioned activities exceeds 50 cubic yards. 2. Work in a watercourse. The amount of material, measured cumulatively (adding together all proposed earthwork) for any of the above mentioned operations exceeds 20 cubic yards and involves altering or obstructing a drainage way or watercourse. 3. Removal of vegetation. Projects which would involve more than one acre of vegetation removal on a site. 4. Temporary Stockpile. Soil stockpiled upon a land area for future site development or for temporary storage as set forth in Section 13.24.080. Vegetation removal is calculated based on the total area of a site which will lack soil cover (i.e. "bare soil") at any given time. Areas subject to previous vegetation removal are not included in this calculation where permanent revegetation has already achieved a minimum of 70 percent coverage. All projects subject to a grading permit must submit an erosion and sediment control plan which includes the rationale used for selecting BMPs. The erosion and sediment control plan may be substituted by a SWPPP if the project requires one. The erosion and sediment control plan must require operators of construction sites to minimize the discharge of pollutants to the MS4 through the installation, implementation or maintenance of BMPs consistent with the California Storm Water Quality Association (CASQA) BMP Handbook or equivalent. Note: The grading thresholds specified in Subsections 1 and 2 above are to be measured cumulatively for each project. A project may not be broken down into smaller components with the intention of avoiding a grading permit. Activities progressing towards a common endeavor are considered a single project. Item 8.k. - Page 15 13.24.060 Grading Plan Requirements. All applications for a grading permit shall be accompanied by a grading plan consistent with this Section. A. Professionals qualified to prepare grading plans. 1. Grading Plans may be prepared by anyone who can accurately provide the necessary information for the application, grading .plan, erosion and sedimentation control plan, drainage plan, and stormwater pollution prevention plan review. This may include the applicant, a draftsperson, designer, certified sedimentation and erosion control specialist or licensed individuals who are normally involved with a project such as a civil engineer, surveyor, architect, or landscape architect. Should additional information be required due to unique physical characteristics of the site, this may require that information be prepared by the appropriate licensed professional (at the discretion of the Director of Community Development). 2. Grading Plans prepared for an Engineered Grading Plan (as defined by Subsection C) may be prepared only by professionals licensed by the State of California to prepare grading and drainage plans. The assistance of other professionals approved by the Director of Community Development is encouraged. These professionals may include landscape architects, soil engineers, geologists, engineering geologists, certified sedimentation and erosion control specialists, botanists, biologists, and archaeologists. B. Grading Plan Content. A grading plan shall be legible and accurately drawn to scale using standard drafting techniques. Plans shall be of sufficient clarity to indicate the nature and extent of the work proposed and show in detail that they will conform to the provisions of this Chapter and all relevant codes and regulations. Plans shall include, but not be limited to, the following information unless waived by the Director of Community Development: 1. General site information. a. The name, address, and phone number of the owner and the person by whom the plans were prepared. b. A description of the land upon which the work is to be performed, including Assessor's Parcel Number, street address, tract, block, and lot number. c. An accurate location map with enough detail to find the site in the field and detailed directions to the site. d. An accurate site plan that delineates the limits of grading activities. e. A written scope of work, including references to any documents associated with the scope of work. Where grading was previously unpermitted, discussion on background and history of the grading activities shall be included. 2. Topography and earthwork quantities. a. Existing or natural ground contours, and proposed ground contours at intervals of no more than two feet for area to be graded and five feet for the remainder of site. On rural parcels exceeding 80 acres, existing and proposed contours shall be shown at two foot intervals for area to be graded, and the remainder of site at 20 foot intervals. The latest USGS topographic maps may be used as a source of information for the 20 foot intervals. Item 8.k. - Page 16 b. An estimate of the volume of earth to be moved, expressed in cubic yards, verified and stamped by the engineer of record. Calculations shall be provided to support the estimate. c. An estimate of the surface area of earth to be moved, expressed in square feet, verified and stamped by the engineer of record. Calculations shall be provided to support the estimate. d. An estimate of the total area of site disturbance, expressed in square feet. This total shall include all vegetation removal in addition to soil disturbance. e. An estimate of total area in square feet of native vegetation to be removed. 3. Cuts and fills. a. Cuts and fills shall be limited to the minimum amount necessary to establish the proposed use. Specify amounts of cut and fill. Identify location of site(s) to receive fill, showing area and depth of fill. Identify location of borrow site(s) and depth of borrow. Whenever possible, cut and fill should be balanced on the site. 1) If fill materials are imported to the site, provide information regarding the proposed source(s) and amount of material. If the source changes due to other materials becoming available, this information shall be provided to the Director of Community Development. 2) If excavated materials are exported provide statement of amount, method of disposal, proposed location(s), and details on applicable permits. 3) If permits are necessary for the site providing the fill material or receiving excavated material, provide evidence that permits have been issued for that site. b. An estimate of the maximum and minimum vertical depth of cuts and fills, expressed in feet and cut and fill slope ratios. c. Any required retaining walls or other means of retaining cuts or fills. Additionally, provide details and calculations of the retaining walls, drainage devices, and all other protective structures to be constructed as part of the grading permit. 4. Finish elevations. a. Elevation of the finish floor of the garage or other parking areas. b. Ground and finish floor elevations at the base of building or structure corners. c. Elevations of the edge of pavement or road at driveway entrance. d. Elevations of the top of wall and bottom of footing of proposed retaining walls. 5. Site improvements and features. a. The location of all existing and proposed surface and subsurface drainage ways and drainage systems on the site and adjacent property which may affect or be affected by the proposed project. ' b. The location of all existing and proposed buildings, structures, easements, groundwater recharge areas, wells or sewage disposal systems on site, and the approximate location of these items on adjacent property that are within 100 feet of the property boundary or which may affect or be affected by the proposed project. Show spot elevations at corners of existing and proposed buildings or structures and lots where proposed grading will occur. Item 8.k. - Page 17 c. Location, description, type or topographic description of existing rock outcropping natural feature, vegetation, individual oak trees, wooded areas or trees that are five inches or greater in diameter measured 4.5 feet above ground level proposed for disturbance and/or removal. Botanical, archaeological, or biological surveys prepared by a qualified individual may be required where warranted. Show centerline of streams and flood plain lines, if applicable. Clearly identify on the plan the boundary and general characteristics of areas within which no disturbance will occur. 6. Soils. a. A copy of a soils map and soils descriptions covering the project site and. adjacent properties (available for free through the USDA Natural Resources Conservation Service online). b. When required by the Director of Community Development, each application for a grading permit shall be accompanied by two sets of supporting data consisting of a civil engineering report, soil engineering report, engineering geology report, erosion and sedimentation control report, and/or any other reports necessary. In many instances this information may be shown on the face of the plan. c. Reports shall be prepared by qualified professionals with experience in report preparation and grading plan implementation. Recommendations included in the reports that are approved by the Director shall be incorporated into the grading plan. (See Subsection C, Engineered Grading Requirements). d. Clearly show groundwater recharge methods that have been incorporated into the project design. e. All applicable dust control measures. C. Engineered Grading Plan requirements. When required pursuant to Subsection C.1, the grading plan shall be prepared and signed and sealed by a qualified, registered civil engineer or other qualified professional licensed by the state to perform such work, and shall include specifications covering construction, inspection and material requirements in addition to the information required in compliance with Subsection B. Additionally, those items required by Subsections C.2 through C.4 shall accompany the grading plans. 1. When required. Engineered grading is required when one or more of the following circumstances exist: a. The grading will involve 5,000 cubic yards or more (cumulative). b. The grading involves site work on slopes of 20 percent or greater. c. The proposed grading is located within a Geologic Study Area or Flood Hazard area. d. The Director of Community Development has cause to believe that geologic hazards may be involved. 2. Site and drainage report. The site and drainage report, shall include, but not be limited to: a. The date the report was prepared and the name, address, and phone number of firm or individual who prepared the report. b. Hydrology calculations showing maximum peak discharges of water runoff for 2 through 10- and 100-year storm frequencies and comparison of runoff with and without project. Hydraulic calculations for existing downstream runoff conveyance systems that will be impacted by the proposed project runoff. Item 8.k. - Page 18 c. Summary of the groundwater recharge methods that have been incorporated into the project design. d. Inspection and approval to establish lines and grades, design criteria for corrective measures, including the required safe storm drainage capacity of channels both on and off-site. e. Soils, geology, or civil engineer's opinions and recommendations concerning adequacy of site to be developed by the proposed grading. f. Sequence and type of recommended inspections. 3. Geotechnical report. The geotechnical report shall be prepared by qualified person license to do geotechnical work and contain, but need not be limited to, all the following information: a. The date the report was prepared and the name, address and phone number of firm or individual who prepared the report. b. Data regarding the nature, distribution, and strength of existing soils. c. Data regarding the nature, distribution, and strength of soil to be placed on the site, if any. d. Conclusions and recommendations for grading procedures. e. Conclusions and recommended designs for interim soil stabilization devices and measures for permanent soil stabilization after construction are completed. f. Design criteria for corrective measures including buttress fills, when necessary. g. Identification of existing cuts and fills on site, recommended measures for compaction, slope stability and other factors affecting suitability for support of a structure. h. Engineer's opinions and recommendations concerning adequacy for the intended use of site to be developed by the proposed grading as affected by soils engineering factors, including the stability of slopes, foundation recommendation, soil design criteria, liquefaction, expansive soil, loose or soft soils, areas of unknown problems, undocumented fill, cut/fill, unusual loading, shallow ground water or springs, and landslides. i. Sequence and type of recommended inspections. 4. Engineering geology report. The engineering geology report shall be prepared by qualified person license to do geotechnical work and comply with protocol approved by the Department of Planning and Building and shall contain, but need not be limited to, the following information: a. The date the report was prepared and the name, address, and phone number of firm or individual who prepared the report. b. An adequate description of the geology of the site. c. Conclusions and recommendations regarding the effect of geologic conditions on the proposed development. d. An opinion on the adequacy for the intended use of site to be developed by the proposed grading, as affected by geologic factors. e. Need for underground drainage devices or opportunities for underground recharge devices. f. Sequence and type of recommended inspections. Item 8.k. - Page 19 g. If the proposed grading is for a habitable structure, and the geologist has identified evidence of recent fault ruptures occurring near the proposed structure, additional geological information will be necessary. The guidelines suggested in the California Division of Mines and Geology Notes #49 or subsequent additions shall be used to prepare this supplemental report. When the Director of Community Development has cause to believe that geologic hazards may be involved, the regular grading operation shall be required to conform to engineered grading requirements. 13.24.070 Design Standards for Grading. A. Grading standards. 1. Excavation standards. All excavations are to be conducted in compliance with the provisions of Section J106 of the California Building Code and the following standards: a. No excavation shall be made with a cut face steeper in slope than two horizontal to one vertical, except under one or more of the following conditions. 1) The Director of Community Development may permit an excavation to be made with a cut face steeper than two horizontal to one vertical if the applicant provides a slope stability analysis prepared by a geotechnical engineer or engineering geologist that the material making up the slope of the excavation and the underlying earth material is capable of standing on a steeper slope, and a certified soil and erosion control specialist or other qualified professional indicates, in writing, that either it is feasible to mitigate erosion and sedimentation impacts and that successful revegetation of the site can be accomplished or that due to the nature or composition of the cut slope, erosion and sedimentation measures and revegetation are unnecessary. 2) A retaining wall or other approved support which also mitigates visual impacts of the device is provided to support the face of the excavation. b. The Director of Community Development may require an excavation to be made with cut face flatter in slope than two horizontal to one vertical if a slope stability analysis or other appropriate method of review indicates that the material in which the excavation is to be made is such that the flatter cut slope is necessary for stability, safety, or to prevent erosion and sedimentation and stormwater impacts. ·. c. No cut slope shall exceed a height of 25 feet without intervening terraces having a minimum width of six feet. These terraces shall be vertically spaced at intervals of 25 feet except that for slopes less than 40 feet in vertical height the terrace shall be approximately at mid-height. Suitable access shall be provided to permit cleaning and maintenance. The Director of Community Development may modify this requirement because of geologic or other special conditions. d. The border of all cut slopes shall be rounded off to a minimum radius of five feet to blend with the natural terrain. e. All cut slopes shall be within parcels under common ownership unless written permission is granted by the adjacent owner. 2. Fill standards. All fills are to be conducted in compliance with the provisions of Section J107 of the California Building Code Appendix J and the following standards: Item 8.k. - Page 20 a. No fill shall be made which creates any exposed surface steeper in slope than two horizontal to one vertical, except under one or more of the following conditions: 1) A retaining wall or other approved support is provided to support the face of the fill which also mitigates visual impacts of the device. 2) The Director of Community Development may permit a fill to be made which creates an exposed surface steeper in slope than two horizontal to one vertical (2:1) if a geotechnical engineering report demonstrates that slope stability will be ensured. The geotechnical engineer shall certify that the strength characteristics of the material to be used in the fill are such as to produce a safe and stable slope and that the areas on which the fill is to be placed are suitable to support the fill. Additionally, a certified soil and erosion control specialist or other qualified professional shall indicate in writing that it is feasible to prevent erosion and sedimentation impacts, and successful revegetation of the site can be accomplished. All such reports are subject to the approval of the Director of Community Development. b. The Director of Community Development may require that fill be constructed with an exposed surface flatter than two horizontal to one vertical (2:1) if a slope stability analysis or other appropriate method of review indicates that such flatter surface is necessary for stability, safety, or to prevent erosion and sedimentation impacts. c. Unless specified as a non-structural land reclamation, erosion control, or agricultural fill, all fills shall be placed, compacted, inspected, and tested in compliance with the following provisions: 1 ) The natural ground surface shall be prepared to receive fill by removing vegetation, non- complying fill, topsoil and other unsuitable materials. The surface shall be scarified to provide a bond with the new fill and where slopes are steeper than five horizontal to one vertical (5:1) and the height is greater than five feet, by benching into sound bedrock or other competent material as determined by the soils engineer. The bench under the toe of a fill on a slope steeper than five horizontal to one vertical (5:1) shall be at least 10 feet wide. The area beyond the toe of fill shall be sloped for sheet overflow or a paved drain shall be provided. When fill is to be placed over a cut, the bench under the toe of fill shall be at least 10 feet wide, but the cut shall be made before placing the fill. The soils engineer, engineering geologist, or both, shall certify that the bench is a suitable foundation for the proposed fill. 2) Except as otherwise permitted by the Director of Community Development, no rock or similar irreducible material with a maximum dimension greater than six inches shall be buried or placed in fills. No organic material shall be permitted in structural fills. The Director of Community Development may permit placement of larger rock when the Soils Engineer properly devises a method of placement, continuously inspects its placement, and approves the fill stability. The following conditions shall also apply: a. Prior to issuance of the grading permit, potential rock disposal areas shall be identified on the grading plan. b. Rock sizes greater than six inches in maximum dimension shall be 10 feet or more below grade, measured vertically. c. Rocks shall be placed so as to assure filling of all voids with well-graded soil. 3) A fill shall be spread in a series of horizontal lifts as specified by the geotechnical engineer or other approved professional approved by the Director of Community Development. The distribution of material throughout each layer shall be free of lenses, Item 8.k. - Page 21 pockets or layers of material differing substantially in texture or gradation from the surrounding material. All material shall be compacted into a fill of uniform moisture and density as specified in Subsection A.2.c.(4). 4) All fills shall be compacted to a minimum of 90 percent of maximum density as determined by ASTM D 1557-(latest edition) or other approved testing method giving equivalent test results. Field density shall be determined by ASTM D 1556-(latest edition) or other equivalent methods approved by the Director of Community Development. 5) A field density test, as herein provided, shall be taken for each 24 inches of fill, or portion thereof, measured vertically from the lowest point of the area to be filled, and for each 200 cubic yards of fill placed unless a variation is recommended by the Soils Engineer and approved by the Director of Community Development. In addition, in the case of a subdivision, field density tests shall be taken on lots which receive fill based upon the recommendations of a soils engineer. 6) All fills regulated by this Chapter shall be tested for relative compaction by a qualified geotechnical testing agency. Final reports, including a letter certifying compliance with the terms of this Chapter, and the grading permit, setting forth densities, relative compaction and other fill characteristics shall be prepared and signed by a Geotechnical Engineer. This report shall be submitted to and approved by the Director before any final approval of the fill is given and before any foundation construction begins except for the digging of trenches and placing of reinforcing steel. d. Fills toeing out on natural slopes which are steeper than two horizontal to one vertical shall not be permitted unless evaluated and approved by a geotechnical engineer or engineering geologist. e. The border of fill slopes shall be rounded off to a minimum radius of five feet to blend with the natural terrain. 3. Grading setback standards. Cut and fill slopes shall be set back from site boundaries in compliance with the provisions of Section J108 of the 2013 California Building Code Appendix J and the following standards: Item 8.k. - Page 22 Hl2 BUT 2 FT. MIN. AND 20 FT. MAX. TOE SLOPE CUT OR FILL SLOPE H TOP OF SLOPE H/5 BUT 2 FT. MIN. AND 10 FT. MAX. PA' I . NATURAL OR FINISH GRADE H Under_§ ~30 Over 30 * PA = Permit Area Boundary -Lot line(s) or permit area boundary if the permit area is smaller than the lot involved Figure 1 -Grading Setbacks TABLE NO. 70 REQUIRED SETBACKS FROM PERMIT AREA BOUNDARY (IN FEET) 1 SETBACKS I I b, 1a I 11 10 1H/2 I )HIS I 16 I 15 ·-1- 1Additional width may be required for interceptor drain. Figure No. 2 Item 8.k. - Page 23 a. General. Setback dimensions shall be horizontal distances measured perpendicular to the site boundary. Setback dimensions shall be as shown in Figure 1. b. Stream and Riparian Setback. Tops and toes of cut and/or filled slopes shall be set back far enough to prevent encroachment upon· streams, flood plains, or channels, or body of standing water to provide and maintain an undisturbed protective strip between the grading and the riparian corridor. This strip shall have sufficient filter capacity to prevent degradation of water quality, as determined by the erosion and sediment control specialist and approved by the building official. If it is determined that the filter capacity of the protective strip is insufficient, or development activity will encroach upon riparian zones, additional setback distance and/or erosion control practices may be required. c. Retaining Walls. Retaining walls, when keyed into stable foundations and capable of sustaining the design loads, may be used to reduce the required cut and fill setbacks when recommended by the civil or soils engineer, or engineering geologist and approved by the building official. d. Top of cut slope. The top of the cut slopes shall not be closer to a site boundary line than one fifth of the vertical height of cut with a minimum of two feet and a maximum of 10 feet. The setback may need to be increased for any required interceptor drains or maintenance easements. The Director may approve adjustments as a condition of the permit, as required by individual site conditions. e. Toe of fill slope. The toe of fill slopes shall not be closer to the site boundary line than one- half the height of the slope with a minimum of two feet and a maximum of 20 feet. Where a fill slope is to be located near the site boundary and the adjacent off-site property is developed, or site conditions warrant, special precautions shall be incorporated in the work as the Director of Community Development deems necessary to protect the adjoining property from damage as a result of such grading. These precautions shall include, but are not limited to the following: 1) Additional setbacks. 2) Provisions for retaining or slough walls. 3) Mechanical or vegetative treatment of the fill slope to minimize erosion. 4) Provisions for the control of surface waters. 5) Provisions for maintenance access. f. Modification of slope location. The Director of Community Development may approve . alternate setbacks. The Director of Community Development may require an investigation and recommendation by a qualified engineer, engineering geologist, or erosion control specialist to demonstrate that the intent of this Section has been satisfied. g. Distance from property line. No cut or fill shall be made which is sufficiently close to the property line to endanger any adjoining public or private property or structures without supporting and protecting such property or structures from any settling, cracking, or other damage which might result. h. Other Restrictions and/or Minimums. Other requirements may also be increased or relaxed upon review by the building official if he or she finds the deviations consistent with safety and stability and to provide access for slope maintenance and drainage. Item 8.k. - Page 24 4. Landform alterations within public view corridors. Grading, vegetation removal, and other landform alterations shall be minimized on sites located within areas determined by the Director of Community Development to be a public view corridor from collector or arterial roads. Where feasible, contours of finished grading are to blend with adjacent natural terrain to achieve a consistent grade and appearance. 5. Grading near watercourses. Grading, dredging or diking shall not alter any intermittent or perennial stream, or natural body of water shown on any USGS 7-1/2 minute map, except as permitted through approval of a City drainage plan and a streambed alteration permit from the California Department of Fish and Wildlife issued under Sections 1601 or 1602 of the Fish and Wildlife Code. Watercourses shall be protected as follows: a. Watercourses shall not be obstructed unless an alternate drainage facility is approved. b. Fills placed within watercourses shall have suitable protection against erosion during flooding. c. Grading equipment shall not cross or disturb channels containing live streams without siltation control measures approved by the Director of Community Development in place. d. Excavated materials shall not be deposited or stored in or alongside a watercourse where the materials can be washed away by high water or stormwater runoff. 13.24.080 Temporary Stockpiling Permits. The Director of Community Development may issue a permit for temporary stockpiling (storage} of earth conforming to the following: A. Requirements. Temporary stockpiling shall: 1} Not exceed 7,000 cubic yards and cover less than one acre in area; 2) Be on a single lot; 3) Not located on or across or affect any surface water body or divert existing drainage courses; 4) Not have a fill bank in excess of 6 feet measured vertically from the toe of the slope to the top of the slope; 5) Not exceed 18 months from the date any stockpiled material is initially placed to the date all material is removed; 6) Not result in exposed fill slopes steeper in average slope than two horizontal to one vertical, including benches and roundings to ensure stability and reduce visual impacts; 7) Install and maintain measures to protect against erosion and instability and ensure that runoff water leaving the premises will not contain sand, silt or other debris; 8) Conform to the setbacks identified under Section 13.24.070.A.3; 9) Place materials only on areas previously excavated or disturbed which contain no significant habitat value, designated scenic area, or mapped geological hazard; and 10) Involve only materials for use on the site, not for export, sales or borrow operations. B. Application and Plan. The application shall be signed by the owner of the land on which the earth is to be stockpiled and be accompanied by a stockpiling plan, grading plan or improvement plan. The application shall include the following: 1} A certification that the fill material is for use exclusively on the site; 2) A description of the proposed ultimate use of the stockpiled material; 3) A vicinity sketch showing: a} property lines and the location of all structures within 100 feet of the proposed stockpile and adjacent properties if within 15 feet of the property line; Item 8.k. - Page 25 b) contour lines showing the topography of the existing ground with a maximum contour interval of 5 feet, the quantity of proposed fill; c) elevations, dimensions, location, extent and square footage of the total footprint of the area proposed to be covered by the stockpiled material; d) all drainage devices, walls, cribbing, dams, stormwater protection best management practices or other protective devices to be constructed, including all temporary construction erosion and sediment control devices; e) a map of the drainage area of the land tributary to the site; and f) dust control measures. C. Security. At the time of permit issuance, the applicant shall enter in to an agreement, secured by a cash deposit, to assure the future permanent placement or removal of the stockpiled material. 13.24.090 Design Standards for Drainage A. Drainage standards. Site development shall have no adverse impacts on adjacent and downstream locations. If adverse impacts are identified, off-site erosion, sediment and flood control improvements to the drainage way will be required to eliminate the adverse impacts. Designs for site area drainage and terraces shall be consistent with the Low Impact Development (LID) requirements set by the RWQCB and the following minimum standards: 1. Design and construction. Drainage systems and facilities subject to drainage plan review and approval that are to be located in existing or future public rights-of-way are to be designed and constructed as set forth in the latest edition of the Public Works Department's Public Improvement Standards, or as per the project's conditions of approval. Applicants may request an adjustment pursuant to the Public Improvement Standards in order to allow for a design that is more compliant with LID practices. Other systems and facilities subject to drainage plan review and approval are to be designed in accordance with good engineering practices. The design of drainage facilities in new land divisions and other new development subject to Minor Use Permit or Conditional Use Permit approval shall maximize groundwater recharge through on-site or communitywide stormwater infiltration measures. Examples of such measures include constructed wetlands, vegetated swales or filter strips, small percolation ponds, subsurface infiltration basins, infiltration wells, and recharge basins. Where possible, recharge basins shall be designed to be available for recreational use. 2. Natural channels and runoff. Proposed projects are to include design provisions to retain natural drainage patterns and, when required, limit peak runoff to pre-development levels. To the maximum extent feasible, all drainage courses shall be retained in, or enhanced to appear in, a natural condition, without channelization for flood control. On downhill sites, encourage drainage easements on lower properties so that drainage can be released on the street or other appropriate land area below. 3. Best Management Practices (BMPs). All new development subject to drainage plan review shall use BMPs to address polluted runoff. BMPs shall be consistent with the guidance found in documents such as the LID Handbook. Such measures shall include, but not be limited to: minimizing the use of impervious surfaces (e.g., installing pervious driveways and walkways); directing runoff from roofs and drives to vegetative strips before it leaves the site; and/or managing runoff on the site (e.g., percolation basins); and other Low Impact Design (LID) techniques. The installation of vegetated roadside drainage swales shall be encouraged and, if used, calculated into BMP requirements. The combined set of BMPs shall be designed to treat stormwater runoff up to and including the 85th percentile storm event. 4. Runoff volume. Runoff conveyance systems shall be capable of carrying the computed runoff volume from a 25-year frequency storm or greater if deemed necessary by the Director of Community Development. This may be reduced to a 10-year storm for small watersheds. Item 8.k. - Page 26 5. Interceptors. Concrete ditches, bio-swales or other approved methods capable of intercepting surface runoff waters shall be installed along the top of all cut slopes where the tributary drainage area has a slope 10 percent or greater and a horizontal projection greater than 40 feet. Interceptor drains shall be paved with a minimum of three inches of concrete or gunite and reinforced. They shall have a minimum depth of twelve (12) inches and a minimum paved width of thirty (30) inches measured horizontally across the drain. The slope of drain shall be approved by the Director of Community Development. Energy dissipaters may be required by the Director of Community Development. 6. Berms. Berms or drainage divides at least one foot high and three feet wide at the base shall be constructed at the top of all fill slopes where runoff would be directed towards the top of fill. Berms, ditches, interceptor drains, or swales shall be constructed at the top of cut and filled slopes for protection against water runoff. Paved interceptor drains shall be installed along the top of all cut slopes where the tributary drainage area above slopes towards the cut and has a drainage path greater than forty (40) feet measured horizontally. 7. Over side drains. Over side drains shall be of concrete or corrugated metal pipe having a diameter required by runoff calculations, but not less than eight inches, and shall be aligned so as to minimize velocity at discharge points. Alternate designs, such as LID methods, approved by the Director of Community Development may be permitted. 8. Inlets. Inlets shall be constructed of galvanized iron, or approved equivalent, and shall be provided with overflow structures. 9. Outlets. Outlet structures shall be provided with approved velocity reducers, diversion walls, rip- rap, concrete aprons or similar energy dissipaters where necessary and aligned to minimize downstream erosion and reasonably maximize recharge at discharge points, and shall be approved by the Director of Community Development. 10. Culverts. Culvert size and materials shall be determined by the civil engineer in accordance with standard design criteria and as approved by the building official. Minimum diameter shall be eighteen (18) inches. 11. Terraces. Terraces at least six feet in width shall be established at not more than thirty (30) foot vertical intervals on all cut or fill slopes to control surface drainage and debris except that where only one terrace is required, it shall be at mid-height. For cut or fill slopes greater than sixty (60) feet and up to one hundred twenty (120) feet in vertical height, one terrace at approximately mid- height shall be twelve (12) feet in width. Terrace widths and spacing for cut and fill slopes greater than one hundred twenty (120) feet in height shall be designed by the civil engineer and approved by the Director of Community Development. Suitable access shall be provided to permit proper cleaning and maintenance. Swales or ditches on terraces shall have a minimum gradient of five percent and must be paved with reinforced concrete not less than three inches in thickness or an approved equal paving. They shall have a minimum depth at the deepest point of one foot and a minimum paved width of five feet. A single run of swale or ditch shall not collect runoff from a tributary area exceeding thirteen thousand (13,000) square feet (projected) without discharging into a down drain. 12. Dispersal structures. An approved drainage dispersal structure shall be constructed wherever it is necessary to convert channel flow to sheet flow. 13. Sensitive habitat and groundwater protection. Runoff from roads and development shall not adversely affect sensitive habitat, groundwater resources and downstream areas, and shall be treated to remove floatable trash, heavy metals and chemical pollutants as necessary prior to discharge into surface or groundwater. Item 8.k. - Page 27 14. Groundwater recharge methods. New development shall identify all methods to enhance groundwater recharge. 15. Impervious surfaces. New development shall be designed to minimize the amount of impervious surfaces in order to maximize the amount of on-site infiltration. 16. Rain gutters. Approved rain gutters shall be provided to receive all roof water and dispose of the water in a groundwater enhancing and non-eroding manner where the Director of Community Development determines it to be necessary because of steepness of slope or presence of erodible materials. Direct connection of rain gutter outlets to impervious surfaces shall be minimized. 17. Building site drainage. All graded building pads shall slope a minimum of five percent for ten feet to an approved drainage device, or as approved by the Director of Community Development. The drainage device shall be an approved system which conducts the water to a street, recharge area or drainage way. The top of footing stems or finish floor, if a concrete slab, shall extend above the top of street curb or inlet to the drainage device by a minimum of six inches plus two per cent of the distance from the footing to the drainage device or curb. The Director of Community Development may allow two percent to be used, if, because of terrain or soils, five percent is not reasonably attainable or necessary. 18. Capacity of drainage devices. On graded sites, the Director of Community Development may require that drainage devices calculated to convey runoff from a 25-year frequency storm or greater be installed, if deemed necessary to prevent erosion, to conduct stormwater around buildings or structures and to the nearest recharge area, drainage way, or as approved by the Director of Community Development. 19. Appearance of drainage or recharge devices. Where drainage devices are highly visible from the street or located in the public viewshed, they shall be shielded from view, if practical. Where visible, drainage devices shall be compatible with the character of the area and the existing topography. Exposed concrete overside drains are prohibited within these situations unless a visual analysis indicates the prohibition to be unnecessary. If they are visible, the size shall be the minimum necessary to handle drainage and ensure ability to maintain all drainage devices which collect from the slopes, and shall convey drainage by means of underground pipes or rock-lined ditches or other approved materials to blend with the natural topography in character, color and design. Transitions from natural drainage courses to developed areas shall be accomplished with comparable landscaping and grading to blend with existing topography. Detention, retention, or recharge basins shall be designed as a visual and/or recreational amenity within a project whenever practical. 20. Groundwater Recharge. Groundwater recharge elements must be included in the project design to mitigate the impacts on recharge caused by the reduction in the permeability of soil areas on the site, except when any of the following site characteristics exist: 1. High groundwater in the area limits the effectiveness of recharge efforts or enhancing groundwater recharge would create additional problems related to high groundwater. 2. The entire site being developed is shown to contain impervious soils that would not benefit from recharge efforts. 3. There is a known geologic instability that would be negatively impacted by increased groundwater recharge. 4. It can be demonstrated that no additional runoff will occur from the development. 5. Federal or state regulations prohibit recharge. Item 8.k. - Page 28 B. Groundwater recharge. All areas on the project site that will become impervious or will have their soil permeability impaired (such as compaction of soil under an all weather driveway) must be mitigated to the maximum extent practicable with recharge enhancement elsewhere on the parcel. Offsite mitigation is a secondary alternative. 1. Areas subject to flooding. Buildings or structures are not permitted in an area determined by the Director of Community Development to be subject to flood hazard by inundation, overflow, high velocity flows or erosion, except where the buildings or structures comply with the standards in Section 16.44.050, and provisions are made to eliminate identified hazards to the satisfaction of the Public Works Director. These provisions may include providing adequate drainage facilities, protective walls, suitable fill, raising the floor level of the building or structure, or other means. The building and other structures (including walls and fences) shall be placed on the site so that water or mud flow will not be a hazard to on-or off-site structures or adjacent property. In the application of this standard, the Director of Community Development shall enforce as a minimum the current federal flood plain management regulations as defined in the National Flood Insurance Program authorized by United States Code Title 42, Section 4001-4128 and contained in Title 44 of the Code of Federal Regulations, Part 59 et seq., which are hereby adopted and incorporated into this Title by reference as though they were fully set forth here. 2. Design of flood proofing measures. Flood proofing measures required by the Director of Community Development shall be designed by a licensed architect or registered civil engineer. 3. Sub-drains. The Director of Community Development may require the installation of approved sub-drains in areas where underground water is anticipated. 4. Runoff computations. Runoff computations may be made by the "rational method" except where specific methods for calculating individual residential retention basins have been adopted or with the approval of the Director of Community Development. 5. Alternate designs. Alternate designs which provide equivalent safety and are approved by the Public Works Director may be used in lieu of those contained in this Section. 6. Hydromodification control. If the Director of Community Development has determined that the project could cause off-site erosion or adverse impacts to beneficial uses as a result of an increase in runoff rates and/or duration, the project shall incorporate hydromodification control measures in compliance with Low Impact Development (LID) Handbook requirements. 13.24.100 Drainage Plan Requirements A. Requirements. Drainage plans shall be prepared and submitted for review and approval by the Director of Community Development, where a project: 1. Increases or decreases runoff volume or velocity leaving any point of the site beyond those that existed prior to site disturbance activities; or 2. Involves a land disturbance (grading, or removal of vegetation down to duff or bare soil, by any method) of more than 20,000 square feet; or 3. Will result in an impervious surface of more than 20,000 square feet; or 4. Is subject to local ponding due to soil or topographic conditions; or Item 8.k. - Page 29 5. Is located in an area identified by the Director of Community Development as having a history of flooding or erosion that may be further aggravated by or have a harmful effect on the project or adjoining properties; or 6. Is located within a Flood Hazard (FH) combining designation; or 7. Is located over a known high recharge area identified by the Director of Community Development; or 8. Involves land disturbance or placement of structures within 100 feet of the top bank of any watercourse shown with a blue line on the most current USGS 7% minute quadrangle map; or 9. Involves hillside development on slopes steeper than 10 percent; or 10. May, by altering existing drainage, cause an on-site erosion or inundation hazard, or change the off-site drainage pattern, including, but not limited to any change in the direction, velocity, or volume of flow. B. Drainage plan content. Drainage plans shall be legible and accurately drawn, at an appropriate scale that will enable ready identification and recognition of submitted information. Director of Community Development may require drainage plans to be prepared by a registered civil engineer. 1. Basic drainage plan contents. A drainage plan shall include the following information about the site: a. Flow lines of surface waters onto and off the site. b. Existing and finished contours at two-foot intervals or other topographic information required by the Director of Community Development. c. Building pad, finished floor and street elevations, existing and proposed. d. Location and graphic representation of all existing and proposed natural and manmade drainage facilities for storage or conveyance of runoff, including drainage swales, ditches, culverts and berms, sumps, sediment basins, channels, ponds, storm drains and drop inlets. e. Proposed flood-proofing measures were determined to be necessary by the Director of Community Development and in accordance with Federal Emergency Management Agency (FEMA) requirements. f. For projects where the Director of Community Development or Public Works Director determines that increased discharge rates and durations could result in off-site erosion or other impacts to beneficial uses, the project shall incorporate appropriate hydromodification measures as identified in the Low Impact Development (LID) Handbook. Such measures shall be clearly depicted on the drainage plan. 2. Engineered plan content. In addition to the information required by Subsection B.1, engineered drainage plans are to include: a. An evaluation of the effects of projected runoff on adjacent properties and existing drainage facilities and systems. b. A map showing the drainage area and hydraulic calculations showing the facilities flow carrying capacities for the design storm event and justifying the estimated runoff of the area served by any drain. Include design discharges and velocities for conveyance devices, and storage volumes of sumps, ponds, and sediment basins based on the design storm. Item 8.k. - Page 30 c. Estimates of existing and increased runoff resulting from the proposed improvements and methods for reducing velocity of any increased runoff. d. Methods for enhancing groundwater recharge that have been incorporated into the project design or an explanation of non-necessity of groundwater recharge for this site 13.24.110 Stormwater Management Purpose. The requirements in this Section are intended to reduce pollutant discharges to the Maximum Extent Practicable and to prevent stormwater discharges from causing or contributing to a violation of receiving water quality standards, also known as post-construction stormwater management. These requirements also emphasize protecting and, where degraded, restoring key watershed processes to create and sustain linkages between hydrology, channel geomorphology, and biological health necessary for healthy watersheds. Maintenance and restoration of watershed processes impacted by stormwater management is necessary to protect water quality and the beneficial uses of surface and groundwater. A. Regulated Projects. Regulated projects include all new development or redevelopment projects, both discretionary and ministerial, that create and/or replace at least 2,500 square feet of impervious surface (collectively over the entire project site). B. Stormwater Control Plan (SWCP) Required. Prior to acceptance of an application for a construction permit, grading permit, land use permit or subdivision application associated with a Regulated Project, as defined in this section, the applicant shall submit a Stormwater Control Plan. The SWCP shall demonstrate compliance with all applicable Post Construction Requirements for the Central Coast Region, adopted by the Central Coast Regional Water Quality Control Board under Order R3-2013-0032 and comply with the City's Design Requirements for Post Construction Compliance adopted by the City and incorporated herein by this reference, on file in the Community Development Department. 1. Site Design Checklist. The SWCP for all projects subject to this Section shall demonstrate that the following design strategies have been pursued in order to reduce runoff: a. Limit disturbance of creeks and natural drainage features. b. Minimize compaction of highly permeable soils. c. Limit clearing and grading of native vegetation at the site to the minimum area needed to build the project, allow access, and provide fire protection. d. Minimize impervious surfaces by concentrating improvements on the least-sensitive portions of the site, while leaving the remaining land in natural, undisturbed state. e. Implement at least one of the following strategies: 1) Direct roof runoff into cisterns, rain barrels, underground storage, or a similar mechanism for reuse. 2) Direct roof runoff onto vegetated areas safely away from building foundations and footings, consistent with the California Building Code. 3) Direct roof runoff from sidewalks, walkways, and/or patios onto vegetated areas safely away from building foundations and footings, consistent with the California Building Code. Item 8.k. - Page 31 4) Direct runoff from driveways and/or uncovered parking lots onto vegetated areas safely away from building foundations and footings, consistent with the California Building Code. 5) Construct bike lanes, driveways, uncovered parking lots, sidewalks, walkways, and patios with permeable surfaces. C. Stormwater Quality Standards. Stormwater Control Plans shall be reviewed for consistency with the post-construction stormwater control standards identified in Central Coast Regional Water Quality Control Board Order R3-2013-0032, or subsequent amendments thereto. Standards contained in this order include, but are not limited to, the following: 1. Parking lots. Parking lots with an area of 5,000 square feet or more, or 25 parking spaces or more, shall minimize potential for oil, grease, and other water insoluble hydrocarbons from vehicle drippings and leaks from entering the stormwater conveyance system. Plans shall provide for the following: a. Treat to remove oil and petroleum hydrocarbons; and b. Ensure adequate operation and maintenance of treatment systems, particularly sludge and oil removal and system fouling and plugging prevention control. At a minimum, this shall include a maintenance program which is funded and carried out by the property owner. 2. Maintenance. Long-term maintenance of BMPs shall be established through the recordation of a maintenance agreement and/or Covenants, Conditions, and Restriction (CC&Rs), unless the project does not include structural or treatment control BMPs. This agreement shall be recorded prior to or concurrent with issuance of a construction permit. In order to verify that BMPs will be maintained, the agreement shall do the following: a. Designate responsibility. Identify the party who is responsible for long-term maintenance of structural and treatment control BMPs. b. Address transfer of responsibility. Address how BMPs will be maintained once property has been transferred to private landowners, a homeowners association, or a public entity. c. Reference educational materials. Educational materials shall be required to accompany the first deed transfer. These materials shall provide information on what stormwater management facilities are present, signs that maintenance is needed, how the necessary maintenance can be performed, and assistance that the applicant can provide to the new landowner. The transfer of this information shall also be required with any subsequent sale of the property. d. Address operations and maintenance reporting. Address how and when long- term operations and maintenance will be verified and reported to the City. 13.24.120 Erosion and Sedimentation Control Plan Requirements A. Requirements. An erosion and sedimentation control plan shall be required year-round for the following types of projects: 1. Construction and grading. All construction and grading permit projects. Item 8.k. - Page 32 B. Water Pollution Control Plan (WPCP). All erosion and sedimentation control plans shall be accompanied with a complete WPCP application, unless exempted by the Director or the Public Works Director. Best Management Practices (BMPs} shall be in compliance with CASQA handbook or equivalent. A project SWPPP also can serve as the WPCP. C. Erosion and sedimentation control plan content. An erosion and sedimentation control plan shall address pre-construction, during construction, and post-construction measures. Measures shall be in place to control erosion and sedimentation prior to the commencement of grading and site disturbance activities unless the Director of Planning and Building or the Public Works Director determines temporary measures to be unnecessary based upon location, site characteristics or time of year. Plans may be incorporated into and approved as part of a grading or drainage plan, but must be clearly identified as an erosion and sedimentation control plan. Erosion and sedimentation control plans are reviewed and approved by the Director of Planning and Building or the Public Works Director. The plan shall be prepared by a certified sediment and erosion control specialist, a registered civil engineer, registered architect or landscape architect, certified California nurseryman, licensed landscape contractor, Resource Conservation District or USDA Natural Resources Conservation Service Specialist, or other qualified persons acceptable to the Department of Planning and Building with competence and experience in erosion control plan preparation and implementation. The plan shall consist of graphic and narrative information of sufficient clarity to indicate the nature, extent, location and placement recommendations (including installation procedures and requirements} of the erosion and sedimentation control measures proposed and show in detail that they will conform to the provisions of this Chapter. The location of all practices, methods and devices shall be shown on the grading plan, or on a separate plan at the discretion of the Director. If separate, it shall be attached to the grading plan used in the field. The plan shall contain, but need not be limited to, all the following information unless some of the information is waived by the Director of Community Development or the Public Works Director as not needed for the review of a particular site and its characteristics Grading limits shall be graphically defined on the plan and staked out before site disturbance begins. 1. Proposed pre-construction, during construction, and post-construction methods and a description of the practices to be used for cut or fill slopes to prevent erosive surface runoff. 2. A statement signed by the individual preparing the plan certifying that the amount of site disturbance proposed has been reduced to the maximum extent practicable complies with all applicable standards in this Chapter. 13.24.130 Stormwater Pollution Prevention Plan (SWPPP) Requirements A. Requirement Criteria. Unless exempted by the RWQCB, a Stormwater Pollution Prevention Plan (SWPPP} is required prior to issuance of grading and/or construction permits, and/or prior to approval of subdivision improvement plans, for a project that involves clearing, grubbing, grading, or disturbance to the ground such as stockpiling or excavation that: 1. Results in site disturbance of one acre or more of land area; or 2. Results in site disturbance of less than one acre if the activity is part of a larger common plan of development that encompasses one acre or more of site disturbance. 13.24.140 Design Standards for Stormwater Pollution Prevention Plan. Item 8.k. - Page 33 Stormwater pollution prevention standards. Projects requiring a SWPPP shall comply with the standards outlined in SWRCB General Construction Permit Number CAS000002, or any subsequent General Construction Permits that amend or replace Permit CAS000002. The SWPPP must utilize BMPs consistent with the California Storm Water Quality Association (CASQA) BMP Handbook or equivalent. 13.24.150 Inspections and Compliance Excavation, grading, filling, clearing and erosion control work for which a permit is required shall be subject to inspection by the Community Development Department (Planning, Building and Engineering Divisions) to assure compliance with the approved plans. The Director of Community Development may require supervision, regular inspection, and special testing be performed and certified by the civil engineer (or other professional) who prepared the approved plan; and the civil engineer shall also be responsible for the inspection and approval of work within his or her area of technical specialty. This responsibility shall include, but need not be limited to, inspection and approval as to the establishment of line, grade and drainage of the development area. The Director of Community Development may also require special supervision, inspection and testing be performed by an independent, approved testing agency to ensure compliance with this chapter, the permittee's permit concerns, and/or in accordance with the provisions of Section 306 of the California Building Code and Section 13.24.060 of this Chapter. Approved plans for grading, vegetation removal work, and erosion and sedimentation control (or SWPPP if required) bearing the stamp of the City of Arroyo Grande Engineering or Building Departments shall be maintained at the site during the progress of the work. The Director of Community Development shall inspect or provide for adequate inspection of the project by appropriate professionals at the various stages of the work requiring approval, and at any more frequent intervals necessary to determine that adequate control is being exercised by the professional consultants. Notification. The permittee shall notify the Director of Community Development two working days prior to the beginning of the operation authorized by the permit, two working days before the project is ready for final inspection, and one complete working day prior to any other inspection or testing requested by the permittee. Right of Entry. Filing for a permit under this chapter constitutes a grant of permission for the City to enter the permit area for the purpose of administering this chapter from the date of the application to the termination of the erosion control maintenance period. If necessary, the Director of Community Development shall be supplied with a key or lock combination, or permitted to install a city lock. 1. Required Inspections. Inspections for a grading permit shall be made as provided herein and work shall not continue until approval to proceed has been granted following the requested inspection. The permit holder shall be responsible for requesting inspection through the Director of Community Development as follows: a. Pre-site inspection to determine the suitability of the proposed project and the existing and potential erosion and sediment hazards. b. Pre-construction meeting. At the Director of Community Development discretion, a pre- construction meeting may be required due to site characteristics, required mitigation measures, or complexity of the proposal. Qualified professionals may need to be in attendance. c. Pre-construction stormwater inspection. When the permit holder is ready to begin work, but before any grading or vegetation removal has occurred, inspect and review erosion and sedimentation control BMPs with permit holder to ensure all necessary sediment controls are in place. Subsequent site inspections may be conducted at any time during the life of the project to determine compliance with the erosion and Item 8.k. - Page 34 sedimentation control plan and/or stormwater pollution prevention plan and to ensure that BMPs are being maintained, are effective as installed and to verify that no pollutants of concern are being discharged into receiving water bodies.~ d. Excavation inspection. After the excavation is started, but before the vertical depth of the excavation exceeds ten feet. e. Fill inspection. After the placement of fill is started, but before the vertical height of the fill exceeds ten feet, and at two foot vertical increments thereafter unless waived by the Director of Community Development. In addition, the fill must be inspected by a qualified lab requiring testing for each two feet of fill, or as defined in the soils report. f. Key and bench inspection. After keys and benches are excavated, but before fill is placed. g. Rough grade inspection. When all rough grading has been completed, including terraces, swales, and other drainage devices. h. Post-construction stormwater inspection. When all work has been completed, all disturbed areas of the construction site have been stabilized, and all long-term (permanent) stormwater pollution prevention and erosion and sedimentation control measures have been installed. Consistent with the General Construction Permit (where applicable) and City requirements, in order for the post-construction stormwater inspection to be approved, all soil disturbing activities shall have been completed and one of the following shall have been met: 1) A uniform vegetative cover of 70 percent coverage has been established. In arid areas where native vegetation covers less than 100 percent of the surface, the 70 percent coverage criterion shall be proportionally adjusted (i.e. where native vegetation covers 50 percent: 0.50 x 0.70 = 0.35 -35 percent); or 2) Equivalent stabilization measures have been employed (e.g. fiber blankets, channel liners, mulch, etc.). 3) All temporary erosion and sediment control measures that are no longer needed have been removed. i. Final inspection. When all work, including installation of drainage structures, other protective devices, planting, slope stabilization and all erosion control measures has been completed in accordance with the final approved plan and the required reports have been submitted to the Director of Community Development and accepted as complete. j. Other inspections. In addition to the inspections above, such other inspections of any work to ascertain compliance with the provisions of this chapter and other laws and regulations as may be required by the Director of Community Development including requirements of the NPDES permit of the City of Arroyo Grande for its stormwater discharges. A licensed landscape architect, qualified biologist, archeologist, agricultural advisor, or other qualified professional may be required to be present during inspections. k. Rainy season inspection. During the rainy season (between October 15 and April 15), inspections shall be conducted to verify compliance with required BMPs based on potential for threat to water quality, as determined by the Director of Community Development. Criteria to be considered include area of disturbance, earthwork quantities, and proximity to watercourses. Based on this assessment, a threat priority will be assigned an inspections shall occur as follows: Item 8.k. - Page 35 Construction Site Priority Low Medium High Frequency of Once or twice during Twice or more during Monthly, and prior Inspection the rainy season the rainy season to rain events with 50% chance or more of producing rain. High priority construction sites are defined as all projects subject to the Construction General Permit and a subset of projects not subject to the Construction General Permit that meets one or more of the following circumstances: discharges directly drain to a creek, involves site work on slopes of 20 percent or greater, involves hillside development on slopes steeper than 10 percent, involves more than 20,000 sf of land disturbance, include excavation of 100 CY of materials or more, and/or that have grading located within a geologic study or flood hazard areas. Low priority construction sites include all those that consist primarily of interior improvements only .... Medium construction site priority are those that are neither defined as low or a high construction site priority. A. Exposure of work. Whenever any work for which inspections are required is covered or concealed by other work without having been inspected, the Director of Community Development may require that such work be exposed for examination. B. Post Construction and other Inspections. 1. Best Management Practices (BMPs). Inspectors of the Engineering Department may inspect for adequate installation and functionality of BMPs prescribed by the erosion and sedimentation control plan or SWPPP at any time throughout the year. The inspectors may identify maintenance and repair needs on the site with the permit holder, or permit holder's agent, to ensure compliance with the minimum requirements of BMPs. 2. Corrective action. If the Director of Community Development determines by inspection that grading as authorized is likely to endanger public health, safety or welfare in the deposition of debris on any public street, or interfere with any existing drainage course, the Director of Community Development may require that reasonable safety precautions be taken to remove such likelihood of danger. Written notice to comply shall be provided to the permit holder allowing no more than ten days for corrections to begin unless an imminent hazard to the public health, safety or welfare exists, in which case the corrective work shall begin immediately. C. Special Reports. Periodic reports by a geotechnical engineer, an engineering geologist, or other qualified professional, certifying the compaction or acceptability of all fills may be required. These shall include, but not be limited to, inspection of cleared areas and benches prepared to receive fill and removal of all unsuitable materials, the bearing capacity of the fill to support structures, the placement and compaction of fill materials, and the inspection of buttress fills, subterranean drains, cut slopes and similar devices. D. Inspection by Others. 1. Where the nature of the project, type of soils, geologic conditions or drainage dictate that special engineering, geotechnical engineering, or geological inspections are necessary to prevent danger to public health, safety or welfare, the Director of Community Development may require the permit holder to retain one or more of the following: Item 8.k. - Page 36 a. A civil engineer: to supervise and coordinate all field surveys and the setting of grade stakes in conformity with the plans, to check elevation of grades, inclination of slopes, installation of drainage structures and other matters related to the geometric design of the work, including the design of revised or modified plans, if necessary. b. A geotechnical engineer: to provide either periodic or continuous inspection of all soils work, including grading and compaction. c. An engineering geologist: to provide geological inspections. d. Resource Conservation District: to provide inspections related to drainage and soil erosion prevention. E. Inspection process 1. Grading shall not be commenced until the permit holder or agent has signed an Inspection Agreement to allow the inspector to make the required entries thereon regarding inspection of the work. 2. The permit holder, agent, or contractor shall have an approved set of grading, drainage and erosion and sedimentation control plans, and stormwater pollution prevention plan (if required), on the site and available at all times while work is in progress until final approval. The plans and specifications shall also include any mitigation measures approved by the Environmental Coordinator (if applicable). 3. In the absence of a specific work site designation, the Director of Community Development may require the site to be surveyed and staked by a civil engineer or land surveyor licensed by the State of California so that the proper location of the work on the lot or parcel may be determined. 4. Inspections for a grading permit shall be made as provided herein and work shall not continue until approval to proceed has been granted, following inspection. The permit holder shall be responsible for notifying the Engineering Division at least 24 hours prior to the time when an inspection is necessary. 5. Where the nature of the project, type of soils, geologic condition, drainage, or weather conditions dictate that special engineering, geotechnical engineering, geological, or erosion and sedimentation or asbestos control inspections are necessary to prevent danger to public health, safety or welfare, the Director of Community Development may require the permit holder to retain a licensed professional qualified to perform the following: a. Supervise and coordinate all field surveys and the setting of grade stakes in conformity with the plans; to check elevations or grades; inclination of slopes; elevation and grades of drainage structures and other matters related to the geometric design of the work, including the design of revised or modified plans and "as-graded" plans, if necessary. b. Provide either periodic or continuous inspection of soils work, including grading and compaction. c. Provide geological inspections. d. Inspect all erosion and sedimentation runoff control measures and revegetation practices applied to the site. 6. Where the nature of the project dictates that special environmental monitors be required, the environmental review process and mitigation measures shall establish the manner and timeframe in which this review shall occur. In these instances, the Director of Community Development may Item 8.k. - Page 37 require the permit holder to retain a qualified professional to perform the work identified from these measures. 7. If the civil engineer, geotechnical engineer, geologist, or sediment and erosion control specialist find that the work is not being performed in substantial conformity with this Chapter or the approved plans and specifications, notice shall be given to the person in charge of the grading work and to the Director of Community Development. No work shall proceed unless and until the issuance of such written notice from the Director of Community Development that work may proceed. 8. If the Director of Community Development determines by inspection that grading as authorized is likely to endanger sensitive resources, public health, safety, or welfare in the deposition of debris on any public or private property, or interfere with any existing drainage course, the Director of Community Development shall require that effective precautions be taken to remove such likelihood or danger. Written notice to comply shall be given to the permit holder allowing no more than 10 days for corrections to begin unless an imminent hazard to sensitive resources or the public health, safety or welfare exists, in which case the corrective work shall begin immediately. 9. Final inspection, as required in this Chapter, shall be made to the satisfaction of the Director of Community Development. 13.24.160 Enforcement A. Stop Work Order. 1. Whenever any grading, construction or earthwork is being done contrary to the provisions of any approval or of any rule, regulation, law or ordinance, or whenever approval was based upon purposeful misinformation or misrepresentation, or whenever the public health, safety or welfare is endangered, or any work is not in compliance with the plans or permits approved for the project, the Director of Community Development shall issue a written notice or stop work order on the portion of the work affected. Such notice or order to stop work shall be served upon the property owner and any persons engaged in the doing or causing such work to be done, and any such persons shall forthwith stop such work until authorized by the Director of Community Development to proceed with the work in writing. The notice or order shall state the reason for the notice and no work shall be done on that portion until the matter has been corrected and approval obtained from the Director of Community Development. The order may specify actions necessary to restore the site or provide temporary measures for erosion and sedimentation control until the stop work order has been removed. 2. It shall be unlawful for any person to commence or continue any work regulated under the provisions of this Chapter in violation of, or contrary to any stop work notice or stop work order issued in compliance with this Section, except in conformity to the terms of such order or notice of order, or until relief from such order is obtained from the Director of Community Development or, upon appeal, from the City Council. B. Violations and penalties. 1. Any person, firm, contractor, or corporation whether as principal, agent, employee or otherwise who shall commence, construct, enlarge, alter, repair, or maintain any grading, excavation, or fill, or cause the same t o be done, contrary to or in violation of any provision of this Chapter is subject to civil and/or criminal action. The City Council hereby declares that any grading done contrary to the provisions of this Code is unlawful and a public nuisance. The offense may be filed as either an infraction or a misdemeanor at the discretion of the City of Arroyo Grande City Attorney. Item 8.k. - Page 38 2. In addition to any penalties prescribed, the Director of Community Development shall submit a written report to the appropriate state licensing or professional registration board or society in cases where contractors or professional consultants violate the provisions of this Code. 3. Any person violating any of the provisions of this chapter shall be guilty of a separate offense for each and every day or portion thereof during which any violation of any of the provisions of this chapter is committed, continued, or permitted. 4. Paying a fine or serving a jail sentence shall not relieve any person from responsibility for correcting any condition which violates any provision of this Title. C. Injunctions, civil remedies, penalties, and costs. 1. Any person, firm, contractor, or corporation whether as principal, agent, employee or otherwise who shall commence, construct, enlarge, alter, repair, or maintain any grading, excavation, or fill, or causes the same to be done, contrary to or in violation of any provision of this Chapter shall be subject to injunction against such activity and shall be liable for a civil penalty for each day that the violation continues to exist. 2. When the City Council determines that any person has engaged or, is engaged, in any act(s) which constitute a violation of provision(s) of this Chapter, or order issued, the City Attorney or the City Council may make application to the Superior Court for an order enjoining such acts or practices, or for an order directing compliance, and upon a showing that such person has engaged in any such acts or practices, a permanent or temporary injunction, restraining order, or other order may be granted by a Superior Court having jurisdiction over the cause. 3. Any person, firm, or corporation whether as principal, agent, employee or otherwise who shall commence, construct, enlarge, alter, repair, or maintain any grading, excavation, or fill, or causes the same to be done, contrary to or in violation of any provision of this Chapter shall be liable for and obliged to pay to the City of Arroyo Grande for all costs incurred by the City in investigating and obtaining abatement or compliance, or which are attributable to or associated with any enforcement or abatement action, whether such action is administrative, injunctive or legal; and for all damages suffered by the City, its agents, officers or employees as a result of such violation or efforts to enforce or abate the violation. 4. Until all costs, fees and penalties assessed under this Chapter are paid in full, no final approval, Certificates of Completion, Certificates of Compliance, Certificates of Occupancy, land use permits or subdivision maps shall be issued or approved by the Planning and Building Department, Public Works Department, other City agencies, or the City Council. 5. In determining the amount of civil penalty to impose, the Court shall consider all relevant circumstances, including but not limited to, the extent of the harm caused by the conduct constituting the violation; the nature and persistence of such conduct; the length of time over which the conduct occurred; the assets, liabilities and net worth of the persons responsible, whether corporate or individual; any corrective action taken by the persons responsible; and the cooperation or lack of cooperation in efforts toward abatement or correction. D. Additional actions and remedies. 1. Notice of Violation Recordation. Whenever the Director of Community Development determines that work has not been completed in accordance with a permit or the plans and specifications relating thereto, or whenever the Director of Community Development determines that work has been done without the required permit, the Director of Community Development may record a notice of violation. The owner(s) of the property, as revealed by the assessment roll on which the violation is situated, and any other person responsible for the violation shall be notified of the recordation, if their address is available. If the responsible Item 8.k. - Page 39 party fails to act in response to written notification of the Director of Community Development, an erosion problem may be declared a public nuisance and may be abated according to procedures in the Municipal Code. Where there is an emergency condition of erosion or sediment damaging a waterway, marsh, other body of water, or private or public property, the Director of Community Development may have the necessary corrective work done and then bill the responsible party or place a lien against the offending property. 2. Any person who violates any provision of this Chapter or who violates any stop work order or notice may also be in violation of the Federal Clean Water Act and/or the State Porter- Cologne Act and may be subject to prosecution under those Acts, including civil and criminal penalties. 3. Any person who knowingly makes any false material statement, representation, or certification in any record or other document submitted or required to be maintained by this Chapter or the General Construction Permit is subject to civil or criminal action. 4. Any person who violates any order issued by the City for violation of the provisions of this Chapter regulating or prohibiting discharge of both stormwater and non-stormwater, and which causes, or threatens to cause, pollutants to enter the City's stormwater conveyance system shall be liable for such amounts that the City may be fined by the State Water Resources Control Board (SWRCB) or Regional Water Quality Control Board (RWQCB), or the amount of any civil liability imposed on the City for non-compliance with the SWRCB permits. E. Additional Procedures for Unauthorized Grading. 1. Additional Procedures to Remedy Unauthorized Grading Without a Permit-Finding and Declaration. The City Council finds and declares that unauthorized grading without a permit often results in soil erosion, drainage, visual and other destructive long-term impacts which are not satisfactorily alleviated or corrected by the usual enforcement procedures, such as criminal violations or judicial proceedings concerning public nuisances. Further, such grading often causes harm unique to the graded parcel and the properties surrounding it, and the long-term correction measures for each such unauthorized grading requires detailed consideration and formulation, usually after formal public hearings. a. Upon discovery of unauthorized grading without a permit, the Director of Community Development shall, where feasible, contact the owner of the property upon which the grading occurred, and the person who did the grading. If the building official and the owner and contractor can agree within thirty (30) days upon a remedial program which can be accomplished in no more than ninety (90) days, no further city action shall be required at that time. The Director of Community Development shall obtain a cash bond from the owner or contractor, payable upon request, and a right-of-entry form signed by the owner to guarantee the city's right to do the remedial program as agreed if not done by the owner or contractor within the agreed time period. b. If the Director of Community Development cannot reach such a satisfactory agreement, he or she shall, within thirty (30) days, submit a detailed report and recommendations to the City Manager and City Council requesting the initiation of formal council proceedings under the city's nuisance abatement ordinance to abate the public nuisance created on the premises by the unauthorized grading. The object of such proceedings shall be the ordering of corrective measures, subject to the city's power to correct the problem and place a lien upon the real property for all costs of correction. For purposes of the nuisance abatement proceedings, the City Council declares that unauthorized grading without a permit is a public nuisance, per se. Item 8.k. - Page 40 F. Remedies not exclusive. The remedies identified in this Chapter are in addition to and do not supersede or limit any other remedies, including administrative, civil and/or criminal remedies pursuant to federal, state, and local law. The remedies provided in this Chapter shall be cumulative and not exclusive. 13.24.170 Hazards A. General. No person shall cause or allow the persistence of a condition on any site that could cause accelerated erosion. Accelerated erosion shall be controlled and/or prevented by the responsible person or the property owner by using practices outlined hereinafter as applicable. Additional measures may be necessary, and may be specifically required by the building official when work is on geological unstable areas, thirty (30) percent or steeper slopes, and/or on soils with a severe erosion hazard rating by a USDA Soil Survey. Soil sterilants that last longer than four weeks shall not be used on soils or slopes which may subsequently need vegetation for erosion and sediment control. Where feasible, erosion hazard problems shall be controlled no later than the beginning of the next winter or adverse season. B. Hazardous Conditions. Whenever the Director of Community Development determines that any existing excavation or embankment or cut or fill on private property has become a hazard to life and limb, or endangers property, or adversely affects the safety, use or stability of a public way, drainage channel or causes significant impact on the natural resources of the area, the owner of the property upon which the excavation, cut or fill is located, or other person or agent in control of the property, upon receipt of notice in writing from the Director of Community Development shall, within the period specified therein, repair or eliminate such hazard and conform with the requirements of this chapter. C. No permits of any kind shall be issued if the Director of Community Development determines that proposed construction work is hazardous to the extent described above, or the work is subject to a major flood hazard dangerous to life or property, and which hazard cannot be eliminated, prevented, or corrected. 13.24.180 Fees Fees for grading permits and grading, drainage, and erosion and sedimentation control plan checking shall be as set forth in the fee ordinance adopted by the City Council. In compliance with the adopted fee schedule, the Director of Community Development may require payment of actual recorded costs, plus overhead, for those applications which will exceed City fees for processing, plan checking, administration, and/or inspection. 13.24.190 Bonds and securities. The Director of Community Development may require bonds in such form and amounts as may be deemed necessary to assure that the work, if not completed in accordance with the approved plans and specifications, will be corrected to eliminate hazardous conditions. In lieu of a surety bond the applicant may file a cash bond or instrument of credit with the Director of Community Development in an amount equal to that which would be required in the surety bond. The surety bond, or in lieu thereof, less the costs of remedial work, if any, shall be released when the Director of Community Development determines that the best management practices for erosion and sediment control practices have permanently stabilized the site, but not later than eighteen (18) months after installation of all permanent erosion control practices. Item 8.k. - Page 41 EXHIBITB Chapter 13.25 ILLEGAL DISCHARGES AND ILLICIT CONNECTIONS 13.25.010 Purpose. The regulations included in this Chapter are to provide for the health, safety, and general welfare of the environment and the citizens of the City of Arroyo Grande through the regulation of non-storm water discharges to the storm drainage system and receiving waters within the City to the maximum extent practicable as required by federal and state law. 13.25.020 Applicability. This Chapter is applicable to all water entering the storm drain system generated on any developed and undeveloped lands unless explicitly exempted by the State Water Resource Control Board or the City. The requirements of this Chapter are not intended to modify or repeal any other ordinance, rule, regulation, or other provision of law. The requirements of this Chapter are in addition to the requirements of any other ordinance, rule, regulation, or other provision of law, and where any provision of this Chapter imposes restrictions different from those imposed by any other ordinance, rule, regulation, or other provision of law, whichever provision is more restrictive or imposes higher protective standards for human health or the environment shall control. 13.25.030 Objectives. The objectives of this Chapter are: A. To regulate the contribution of pollutants to groundwater and surface waters including but not limited to; Arroyo Grande Creek, Tally Ho Creek, Los Berros Creek or Meadow Creek by storm water discharges. B. To prohibit illicit connections and illegal discharges to the storm drain system. C. To establish legal authority to carry out all inspection, surveillance, monitoring, and enforcement procedures necessary to ensure compliance with this Chapter. 13.25.040 Definitions. For the purpose of this Chapter, certain words and phrases are defined as follows, and certain provisions shall be construed as herein set forth, unless it shall be apparent from the context that they have a different meaning. A. "Basin Plan" refers to the Central Coast Regional Water Quality Control Board adopted Water Quality Control Plan, Central Coast Basin that designates Item 8.k. - Page 42 Ordinance No. 14-_ -Exhibit B Page2 beneficial uses, establishes water quality objectives, and contains implementation programs and policies to achieve those objectives for receiving waters within the Region. B. "California Toxics Rule" refers to regulations codified in 40 CFR Section 131.36 and Section 131.38 respectively, which establish numeric criteria for priority toxic pollutants for California's inland surface waters, enclosed bays, and estuaries. C. "Incidental runoff' shall mean the unintended amount of runoff, which escapes the areas of intended use (e.g., minimal over-spray from sprinklers). Water leaving an intended use area is not considered incidental if it is a result of: (1) inadequate or improper facility design; (2) excessive application; (3) intentional overflow or application; or (4) negligence. D. "Illegal discharge" shall mean any direct or indirect non-storm water discharge to the storm drain system including discharges from commercial and non-profit car washes, mobile cleaning services, pressure washing operations and non-storm water runoff from irrigated areas that is not considered incidental runoff except as exempted in Section 13.25.060. Illegal discharges are also any discharge that may cause or threaten to cause or contributes to an exceedance of any water quality standard in a Statewide Water Quality Control Plan, the California Toxics Rule, or the Basin Plan. E. "Storm drain system" shall mean the system of conveyances (including sidewalks, roads with drainage systems, municipal streets, catch basins, curbs, gutters, ditches, man-made channels, or storm drains) designed or used for collecting or conveying storm water, and that is not used for collecting or conveying sewage. F. "Non-storm water discharge" shall mean any discharge to the storm drain system that is not composed entirely of storm water. G. "Person" shall mean any individual, association, organization, partnership, firm, corporation or other entity living, working or visiting the City. H. "Statewide Water Quality Control Plan" refers to documents issued at the State level for the conservation, development, and utilization of the water resources of the State. They currently consist of the Oceans Plan, Bay-Delta Plan, Thermal Plan, and Freshwater and Estuarine Plan, with future plans under development for Nutrients for Inland Surface Water of the State, and Trash Controls in California Waters (partial list). 13.25.050 Authority. The Public Works Director shall have the authority, to detect and eliminate illegal discharges and illicit connections to the storm drain system. This includes entering onto private property for the purpose of inspecting, at reasonable times, any facility, equipment, practices, or operations for compliance with this Chapter. Should the Public Works Director suspect that an illegal discharge or illicit connection is present, the Public Works Director may do any or all of the following: Item 8.k. - Page 43 Ordinance No. 14-_ -Exhibit B Page 3 A. For non-storm water discharges suspected of being sanitary sewage and/or significantly contaminated, require the discharger to promptly cease and desist discharging and/or cleanup and abate their discharge, spill, or pollutant release as soon as possible. B. For suspected illicit connections, require the owner, within 72 hours of notification, to identify the nature of the suspected illicit connection and to identify the outfall location or point of connection to the storm drain system, sanitary sewer system or other discharge point. Should the suspected illicit connection be confirmed, see item (C) below. C. For illegal discharges and illicit connections, require the discharger to promptly cease and desist discharging and/or cleanup and abate their discharge, spill, or pollutant release within 72 hours of notification. D. For incidental runoff, require the person responsible to detect leaks and correct the leaks within 72 hours of learning of the leaks, and remedy other situations within 10 days, which may include properly designing and aiming sprinkler heads, and/or not irrigating during precipitation events. 13.25.060 Prohibition of Illegal Discharges. No person shall throw, drain, or otherwise discharge, cause, or allow others under its control to throw, drain, or otherwise discharge into the storm drain system or to groundwater and surface waters, including but not limited to; Arroyo Grande Creek, Tally Ho Creek, Los Berros Creek or Meadow Creek, any material other than storm water, except as allowed by this Chapter or as otherwise authorized by a separate NPDES Permit, waiver, or waste discharge order issued to the discharger and administered under the authority of the United States Environmental Protection Agency (EPA), provided that the discharger is in full compliance with all requirements of the permit, waiver, or order and other applicable laws and regulations, and provided that written approval has been granted for any discharge to the storm drain system. The following non-storm water discharges may be allowed provided appropriate control measures to minimize the impacts of such discharges are consistent with the California Stormwater Quality Association (CASQA) Best Management Practices Handbook, or equivalent precautions are taken: (A) water line flushing; (B) individual residential car washing; (C) diverted stream flows; (D) rising ground waters; (E) uncontaminated ground water infiltration (as defined at 40 C.F. R. §35.2005(20)) to separate storm sewers; (F) uncontaminated pumped ground water; (G) discharges from potable water sources; (H) foundation drains; (I) air conditioning condensation; (J) springs; Item 8.k. - Page 44 Ordinance No. 14-_ -Exhibit B Page4 (K) water from crawl space pumps; (L) footing drains; (M) flows from riparian habitats and wetlands; (N) de-chlorinated swimming pool discharges; (0) incidental runoff from landscaped areas; (P) discharges or flow from firefighting; and (Q) other discharges approved by the Public Works Director and specified in writing as being necessary to protect public health and safety. This provision does not obviate the need to obtain any other appropriate permits, such as discharges which are required to be enrolled under Order R3-2011-0223 'Waste Discharge Requirements National Pollution Discharge Elimination System (NPDES) General Permit for Discharges with Low Threat to Water Quality." 13.25.070 Prohibition of Illegal Connections. The construction, use, maintenance or continued existence of illicit connections to the storm drain system is prohibited. This prohibition expressly includes, without limitation, illicit connections made in the past, regardless of whether said drain or connection had been previously allowed, permitted, or approved by an authorized enforcement agency or permissible under law or practices applicable or prevailing at the time of connection. A. Illicit connections include any drain or conveyance, whether on the surface or subsurface that allows an illegal discharge to enter the storm drain system including but not limited to, any conveyances that allow any non-storm water discharge including sewage, processed wastewater, and wash water to enter the storm drain system, and any connections to the storm drain system from indoor drains and sinks or, any drain or conveyance connected from a commercial or industrial land use to the storm drain system that has not been documented in plans, maps, or equivalent records and approved by an authorized enforcement agency. B. Improper connections in violation of this Chapter must be disconnected and redirected, if necessary, to an approved onsite wastewater management system or the sanitary sewer system upon approval of the City. C. Any drain or conveyance that has not been documented in plans, maps or equivalent, and which may be connected to the storm drain system, shall be located by the owner or occupant of that property upon receipt of written notice of violation from the City requiring that such locating be completed. Such notice will specify a 72 hour time period within which the location of the drain or conveyance is to be determined, that the drain or conveyance be identified as storm drain, sanitary sewer or other, and that the outfall location or point of connection to the storm drain system, sanitary sewer system or other discharge point be identified. Results of these investigations are to be documented and provided to the Public Works Director. Item 8.k. - Page 45 Ordinance No. 14-_ -Exhibit B Page 5 13.25.080 Violations. It shall be unlawful for any person to violate any provision or fail to comply with any of the requirements of this Chapter. Any person who has violated or continues to violate the provisions of this Chapter, may be subject to the enforcement actions outlined in this section or may be restrained by injunction or otherwise abated in a manner provided by law. A. In the event the violation constitutes an immediate danger to public health or public safety, the City is authorized to enter upon the subject private property, without giving prior notice, to take any and all measures necessary to abate the violation and/or restore the property. B. Warning Notice. When the City finds that any person has violated, or continues to violate, any provision of this Chapter, or any order issued hereunder, the City may serve upon that person a written Warning Notice, specifying the particular violation believed to have occurred and requesting the discharger to immediately investigate the matter and to seek a resolution whereby any offending discharge will cease. Investigation and/or resolution of the matter in response to the Warning Notice in no way relieve the alleged violator of liability for any violations occurring before or after receipt of the Warning Notice. Nothing in this subsection shall limit the authority of the City to take any action, including emergency action or any other enforcement action, without first issuing a Warning Notice. C. Notice of Violation. Whenever the City finds that a person has violated a prohibition or failed to meet a requirement of this Chapter, the City may order compliance by written Notice of Violation to the responsible person. The Notice of Violation shall contain: ( 1 ) The name and address of the alleged violator; (2) The address when available or a description of the building, structure or land upon which the violation is occurring, or has occurred; (3) A statement specifying the nature of the violation; (4) A description of the remedial measures necessary to restore compliance with this Chapter and a time schedule for the completion of such remedial action; (5) A statement of the penalty or penalties that shall or may be assessed against the person to whom the notice of violation is directed; (6) A statement that the determination of violation may be appealed to the City Public Works Director by filing a written notice of appeal within 10 days of service of notice of violation; and (7) A statement specifying that, should the violator fail to restore compliance within the established time schedule, the work will be done by a designated governmental agency or a contractor and the expense thereof shall be charged to the violator. Item 8.k. - Page 46 Ordinance No. 14-_ -Exhibit B Page 6 Such notice may require without limitation: (1) The performance of monitoring, analyses, and reporting; (2) The elimination of illicit connections or discharges; (3) That violating discharges, practices, or operations shall cease and desist; (4) The abatement or remediation of storm water pollution or contamination hazards and the restoration of any affected property; (5) Payment of restitution to cover all administrative, labor and remediation costs incurred by the City; and (6) The implementation of source control or treatment BMPs consistent with the California Storm Water Quality Association (CASQA) Best Management Practices Handbooks or equivalent. D. Penalties. In the event the alleged violator fails to take the remedial measures set forth in the notice of violation or otherwise fails to cure the violations described therein, the alleged violator is subject to civil and/or criminal action in accordance with Chapter 1.16 of this Code. E. Compensatory Action. In lieu of enforcement proceedings, penalties, and remedies authorized by this Chapter, the City may impose upon a violator, alternative compensatory options, such as storm drain stenciling, attendance at compliance workshops, creek cleanup, etc. Item 8.k. - Page 47 Exhibit C City of Arroyo Grande Design Requirements for Post Construction Stonnwater Compliance Purpose The purpose of this document is to provide guidance and direction on how to comply with Post- Construction Storm water Requirements (PCR's) within the City of Arroyo Grande. This document is intended to be used by developers, contractors, builders, designer8, engineers, architects, planners, homeowners, and all others interested in learning how to address stormwater quality during the planning, design, construction and maintenance phases of a project. It is meant to be used as an aid for both onsite and public improvement projects. Project applicants should use this document to: • Determine which performance requirement apply • Understand how each performance requirement will be applied within the City • Obtain direction regarding means of demonstrating compliance Impact of Development on Water Resources Undeveloped natural landscape areas such as forests and grasslands act like sponges for rainfall. When natural landscape areas are covered with impervious (nonporous) surfaces like roads, parking lots, and roofs, this "sponge-like" function is lost and the amount of rainfall that can be absorbed is considerably reduced. The percentage of impervious surface area of a site influences how much stormwater is infiltrated into the ground, evapotranspirated back into the atmosphere, or leaves the site as stormwater runoff. See figure 1. When the amount of impervious surface area of a site is altered the normal watershed processes is also altered. This can lead to a significant host of problems including: • Increased loads of chemical pollutants; • Increased toxicity; • Changes to flow magnitude, frequency, and seasonality of various discharges; • Physical changes to stream, lake, or wetland habitats; • Changes in the energy dynamics of food webs, sunlight, and temperature; • Changes in biotic interactions between native and exotic species. Changes in impervious surface area can also alter the amount and quality of stormwater that infiltrates and recharges our groundwater aquifers. Item 8.k. - Page 48 25% shallow infiltration 40% evapotranspiration 10% runoff L-- T 25% deep ~ infiltration 21% shallow infiltration 38% evapotranspiration /" "'-1 ,--- 20% runoff /1 /' \ -.\: k--Tc 21% deep • infiltration Natural Ground Cover 10%-20% Impervious Surface 20% shallow infiltration 35% evapotranspiration ~ ! . 30% runoff / I \ 15% deep ~ infiltration --••••• .... , •••• •••• ••••• ......... '•. tll l!it &:l-1• • mmm3 , •• Cl f3 l!:l , •• Cl~:O :::gc!l!l !• a. 10% shallow infiltration 30% evapotranspiration ~~ -· ! 5% deep +-infiltration 35%-50% Impervious Surface 75%-100% Impervious Surface Figure 1. The relationship between impervious surface area, runoff, infiltration and evapotranspiration. (Stream Corridor Restoration: Principles, Processes, & Practices, FISWG 1998) The loss of infiltration from urbanization has also resulted in significant groundwater changes. AB more surface area becomes covered with impervious surfaces, less water is able to seep back into the ground. Reduced groundwater recharge rates may result in lower base flows during dry weather as less groundwater is available to move through the soil and into stream channels and aquifers. See Chapter 13.05 of the City's Municipal Code for more on City's regulations regarding Water Conservation. To protect surface water quality and groundwater resources, new development and significant redevelopment projects should be designed, constructed, and maintained to minimize the interruption of natural watershed processes and to treat storm water as a resource and an asset, instead of a waste product. Item 8.k. - Page 49 Post Construction Requirements The Central Coast Regional Water Quality Control Board recognizes that it is necessary to protect watershed processes so that beneficial uses of receiving waters are maintained and, were applicable, restored. The primary objective of these Post-Construction Stormwater Management Requirements is to ensure reduction of pollutant discharges to the Maximum Extent Practicable and preventing stormwater discharges from causing or contribution to a violation of receiving water quality standards in all applicable development projects that require approvals and/or permit is issued under the planning, building or other comparable authority. To address the impacts of development on water quality, the National Pollutant Discharge Elimination System (NPDES) Small Municipal Separate Storm Sewer System (MS4) General Permit requires the City of Arroyo Grande to develop and implement a Guidance Document that includes specific Best Management Practices (BMPs). Agure 3-2. Which Performance ReQuirements Apply? .YES Table 3-1 :';N'r:i ---.,,· --Do•• proj9ct crollt9 °'""' .... < 5.DDD st ol net YES Do88 project craat• Dt .-.pt.ca -Campliamty drains to •non am uadraU.d depression • Projut is IAcatad oul.Slde of County MS4 Parm11 At11• tne App A) imparviaaa arva7 ~~--• • -I /:, . : (o YES. YES ~=--• . <. 1 &.000 al of nat impcnriom:..-..7 Table 3-2 -Road end parlring lot main1enanca I Sida11'1118f1t 1r.1d blcyclli IBM pro;act.s (wben1 no 1111i.r imperviam surfaces •re crnttd or r11iilaadl, and built ta cir11ct stmmwalar 10 ••cam nguatad ..... II Trds and pathways 1Wtr9ro no atfmr Snpnniaus sar~ .,. C'l'Wl!lt.d ar r•pl:emdl, end budt lD dlroct: stomrwatar nriofl lD adjamnt ngatai.d arus II Underground utd1ty propieu ddt replace the ground surfaco with in·•ind matarial or matariala with s:milar runGff c.ha1'11ctau•be.SI I Curb end gunar improv11111ent or naplec:amenl pn1:J8Cls that are not pan al the •nv add1taonai cre•tiDn or raplac9fnant of irnperwious-curf•ca am (e.g. :RdhwDls. rudway) • Second story •dditJOns thH da not incn1ua tl1D building faotp1in1 Rml38d tnol bw:a cfrutty on the ground) dlld:s. 1hirs. ar ..... ..nrwavs dKigrmd ~th spmcas ao •!~Vlf for water d.-einaQll' Photovoltaic .sysums mstalllld on1onr uistulg roof 01 Glbm impennous mufacu. and pa.nab locatad ov1n p:1nnous stD"l•e11s with w.lkn•:nt•1n11d grass or veg.at.ated ~r. or panel erravs Wth e buffer strip 11t Iha mast~ gr11dillnt row t»f panatm Temporary structts'9S tin place lor le.&a dmn aia monlhsl ~)YES ,.-.-p~ .......... ' --' Applicable ta : ~ • P,.ajeat . ~ft=J· lcalationl I u Imp I m I ,,--_:___j -___ ___J',.;_, -----~ -i:- ••• YES~ PR #2 ~D-p<ajectc<9ata LWO .• >:!2.500"1alaaw ~ •ndnplaced ..._ .................. , YES __ ------~-• . . ~ . PR4t4 'PR .. 5 JPR#1 PR#TB '.::=:=:::::'. '----~. • See Appe:nd1x D If site unable to retain required PR3 Volurno:s Figure 2. Performance Requirement Flow Chart (Source: County of San Luis Obispo) ' ''· Item 8.k. - Page 50 Regulated projects include all new development or redevelopment projects that create and/or replace greater than or equal to 2,500 square feet of impervious surface (collectively over the entire project site). Using the flow chart Figure 2, determine ifthe project is: • EXEMPTor • SUBJECT TO ONE OR MORE PERFORMANCE REQURIEMENT (i.e. the project is regulated), The project is exempt if the project retains 100% of stormwater on site for all storms or if the project consist of only one of the items listed in Draft Resolution No. R3-2013-0032, Section B. Post - Construction Requirements 1 b. Typically, maintenance and utility projects are also considered "exempt" from post-construction requirements specified by the Regional Board. Examples of exempt maintenance projects include routine overlays and slurry seals. Examples of utility projects that are "exempt" include the installation of an ADA ramps, or solar panels on rooftops, or repair of roads or aerial utilities. If the project meets the criteria to be considered "Exempt'', project applicants are still encouraged to implement practices that will reduce stormwater impacts associated with their proposed development. Performance Requirements If the project is considered to be a Regulated project, the regulated project will be required to meet Performance Requirement 1 (PR 1). Many regulated projects are required to meet additional performance requirements. To determine if the project must meet additional requirements, you must determine the Net Impervious Area. The Net Impervious Area is the total (including new and replaced) post-construction impervious areas, minus any reduction in total imperviousness from the pre-project to post-project conditions. Permeable pavements may only be excluded from the impervious surface area calculation if they are designed to infiltrate. Net impervious area New and replaced impervious area Pre-project to post-project reduction in impervious area, if any Pre-project impervious areas consists of all hard, non-vegetated surface area that prevents or significantly limits the entry of water into the soil mantle, as would occur under natural conditions prior to development. Common impervious surfaces include, but are not limited to, roof tops, walkways, patios, driveways, parking lots or storage areas, concrete or asphalt paving, surfaces which impede the natural infiltration of stormwater. Open, uncovered retention/detention facilities shall not be considered as impervious surfaces for purposes of determining whether the thresholds for application of Performance Requirements are exceeded. However, for modeling purposes, open, uncovered facilities that retain/detain water (e.g., retention ponds, pools) shall be considered impervious surfaces. Item 8.k. - Page 51 Total Project Site Area is the area defined by the legal boundaries of a parcel or parcels of land which the new development or redevelopment takes place. Post-project Impervious surface areas is the total (including new and replaced) impervious areas on the development site once the project is completely constructed. They include, but are not limited to: roof tops, walkways, patios, driveways, parking lots or storage areas, concrete or asphalt paving, surfaces which impede the natural infiltration of stormwater. It does not include open, uncovered retention/detention facilities. New (%) is the portion of the post-project impervious area that did replace an existing pervious surface area. Replaced (%) is the portion of the post-project impervious area that replaced an existing impervious surface area. Total Disturbed Area is the portion of the total project site area that will be subject to construction, used as a staging or storage area, or whose vegetation and soils are otherwise directly impacted by the project. An applicant will be required to provide supporting documentation regarding permeable paver (or alternate surface) areas excluded from impervious area calculations. The five Post-Construction Requirements (PCRs) developed by the State Regional Water Quality Control Board are summarized below: Performance Requirement 1: Site Design and Runoff Reduction All regulated projects, projects creating and/or replace :'.'.: 2,500 square feet of impervious surface (collectively over the entire project site), including detached single-family home projects, are subject to PR 1 and must minimally incorporate the following Low Impact Development (LID) design strategies into the project. 1. Limit disturbance of creeks and natural drainage features 2. Minimize compaction of highly permeable soils 3. Limit clearing and grading of native vegetation at the site to the minimum area needed to build the project, allow access, and provide fire protection 4. Minimize impervious surfaces by concentrating improvements on the least sensitive portions of the site, while leaving the remaining land in a natural undisturbed state 5. Minimize stormwater runoff by implementing one or more of the following site design measures: i. Direct roof runoff into cisterns or rain barrels for reuse ii. Direct roof runoff onto vegetated areas safely away from building foundations and footings, consistent with California building code 111. Direct runoff from sidewalks, walkways, and/or patios onto vegetated areas safely away from building foundations and footings, consistent with California building code Item 8.k. - Page 52 Iv. Direct runoff from driveways and/or uncovered parking lots onto vegetated areas safely away from building foundations and footings, consistent with California building code v. Construct bike lanes, driveways, uncovered parking lots, sidewalks, walkways, and patios with permeable surfaces The developer shall provide appropriate documentation certifying that project complies with Site Design and Runoff Reduction Performance Requirements. Certification Statement shall clearly identify the level of compliance with each of the applicable performance requirements the project is subject to. All certification shall be signed and stamped by the engineer of Record and shall include qualify and quantify identified deficiencies, per performance requirements. Performance Requirement 2: Water Quality Treatment Projects subject to PR2 are projects with a Net Impervious Area:::: 5,000 square feet, that are not single family homes, and detached single family homes :::: 15,000 square feet of Net Impervious Area. These projects shall treat stormwater runoff to reduce pollutant loads and concentrations using physical, biological and chemical removal. Developer shall provide and include net impervious area calculations. Regulated projects subject to PR2 must treat a defined minimum volume or maximum surface loading rate of runoff using onsite measures. Allowable onsite measures are listed in the order of preference (highest to lowest): • Low Impact Development -implement harvesting and use infiltration, and evapotranspiration measures that collectively retain stormwater runoff equal to the volume of runoff generated by the 85th percentile 24-hour storm event, based on local rainfall data. • Biofiltration Treatment Systems -implement biofiltration systems using facilities that must be demonstrated to be at least as effective as a biofiltration treatment system that meets the following parameters: I. a max surface loading rate of 5" per hour based on a rain intensity of 0.2 inches or two times the 85th percentile hourly rainfall intensity for the applicable area, II. Surface minimum reservoir volume of equal to the biofiltration area times a depth of 6 inches, m. Proper plan selection with a minimum depth of 24 inches and an infiltration rate of 5 in/hr, IV. Subsurface drain/storage layer with an area equal to the biofitration surface area and having a minimum depth of 12 inches. • Non-Retention Based Treatment Systems -implement stormwater control measure that achieve at least one of the following: 1. a volume capacity designed to treat stormwater runoff equal to the runoff generated by the 85th percentile 24-hour storm event ii. a flow capacity sized equal to at least two times the 85th percentile hourly rainfall intensity for the applicable area and equal to at least 0.2 in/hr intensity. Item 8.k. - Page 53 Design alternatives will only be considered if the applicant can demonstrate that ALL of the following measures of equivalent effectiveness are demonstrated: 1. Equal or greater amount of runoff infiltrated or evapotranspired; 2. Equal or lower pollutant concentrations in runoff that is discharged after bio-filtration; 3. Equal or greater protection against shock loadings and spills; and 4. Equal or greater accessibility and ease of inspection and maintenance. Technical guidance for designing bio-retention facilities is available from the Central Coast LID Initiative web site: http://www.centralcoastlidi.org/Central Coast LIDl/LID Structural BMPs.html The guidance includes design specifications and standard plans. It also includes plant lists appropriate for installation of LID and Bio-filtration Systems on the Central Coast. Project subject to PR2 shall include a Stormwater Control Plan (SWCP) containing the following: 1. Project type and address and name of applicant 2. Calculations for total new, replaced and net impervious area pre/post development 3. Applicable requirement for both PR 1 and PR 2 4. Description of all post construction structural stormwater control measures including calculations 5. Documentation certifying that the selection, sizing and design of measures meet requirements Performance Requirement 3: Runoff Retention Performance Requirement 3 shall apply to projects, except detached single family homes, that create and/or replace ~ 15,000 square feet of impervious surface (collectively over the entire project site), and detached single family homes~ 15,000 square feet of net impervious area, WMZs 1, 2. Regulated projects subject to PR3 must retain a designated design storm volume. Applicants of regulated projects subject to this requirement must: 1. Watershed Management Zone 1 : a) Retain 95th Percentile Rainfall Event -Prevent offsite discharge from events up to the 95th percentile 24-hour rainfall event as determined from local'rainfall data.4 b) Compliance must be achieved via infiltration 2. Watershed Management Zone 2: Item 8.k. - Page 54 a) Retain 95th Percentile Rainfall Event -Prevent offsite discharge from events up to the 95th percentile 24-hour rainfall event as determined from local rainfall data. b) Compliance must be achieved via storage, rainwater harvesting, infiltration, and/or evapotranspiration. PR3 regulated projects shall use the following LID development standards: 1. Site Assessment Measures -each Regulated Project shall identify opportunities and constraints to implement LID Stormwater Control Measures. Provide documentation of the following, as appropriate to the development site: a) Site topography including hydrologic features b) Seasonal high groundwater c) Geological analysis including geotechnical hazards d) Soil type and hydrologic soil groups e) Run-on characteristics and existing drainage infrastructure 2. Site Design Measures -Regulated Project shall optimize the use of LID site design measures, as feasible and appropriate at the project site. Regulated Projects subject to Performance Requirement No. 3 must augment design strategies required by Performance Requirement No. 1 with the following: a) Define the development envelope and protected areas, identifying areas that are most suitable for development and areas to be left undisturbed b) Conserve natural areas, including existing trees, other vegetation, and soils c) Limit the overall impervious footprint of the project d) Construct streets, sidewalks, or parking lot aisles to the minimum widths necessary, provided that public safety or mobility uses are not compromised e) Set back development from creeks, wetlands, and riparian habitats f) Conform the site layout along natural landforms g) A void excessive grading and disturbance of vegetation and soils 3. Delineation of discrete Drainage Management Areas (DMAs) -Regulated Project shall delineate DMAs to support a decentralized approach to stormwater management. A map or diagram dividing the entire project site into discrete DMAs shall be provided. Each Regulated Project shall account for the drainage from each DMA using measures identified as follows: Item 8.k. - Page 55 a) Undisturbed and Natural Landscape Areas -each Regulated Project shall implement appropriate Site Design and Runoff Reduction Measures in Performance Requirement No. 1, to reduce the amount of runoff for which retention and treatment is required. Runoff reduction measures that can be used to account for this reduction also include as follows: 1. Undisturbed or areas planted with native, drought-tolerant, or LID appropriate vegetation that do not receive runoff from other areas may be considered self-treating and no additional stormwater management is required. 11. Runoff from impervious surfaces, generated by the rainfall events identified in Section B.4.c, may be directed to undisturbed or natural landscaped areas. When the applicant can demonstrate that this runoff will be infiltrated and will not produce runoff to the storm drain system, or a surface receiving waterbody, or create nuisance ponding that may affect vegetation health or contribute to vector problems, then no additional stormwater management is required for these impervious surfaces. b) Structural Stormwater Control Measures -Where it has been demonstrated in the Stormwater Control Plans, that the use of Site Design measures listed above, Runoff Reduction measures listed in Performance Requirement No. l, and undisturbed and natural landscape has been maximized to the extent feasible, Structural Stormwater Control Measures designed for water quality treatment and/or flow control shall be used to comply with Performance Requirement No. 3. 4. Ten Percent Adjustment for Sites with Technical Infeasibility -Where technical infeasibility, as described in Section C.1.c., prevents full on-site compliance with the Runoff Retention Performance Requirement, on-site retention of the full Retention Volume per Section B.4.d.vi. is not required and the Regulated Project is required to dedicate no less than ten percent of the Regulated Project's Equivalent Impervious Surface Area5 to retention-based Stormwater Control Measures. 5. Off-Site Mitigation -Off-site mitigation is required when Regulated Projects do not retain the full Retention Volume, and 1) fail to demonstrate technical infeasibility of full retention; or 2) demonstrate technical infeasibility of full retention AND fail to dedicate at least ten percent of the Regulated Project's Equivalent Impervious Surface Area to retention-based Stormwater Control Measures. 6. Reporting Requirements -For each Regulated Project subject to the Runoff Retention Performance Requirement, provide the following information in a Stormwater Control Plan. Final project approval shall not be granted until the Stormwater Control Plan for the Regulated Project sufficiently demonstrates the Regulated Project design meets the Water Quality Treatment and Runoff Retention Performance Requirements. Performance Requirement 4: Peak Management All Regulated Projects that create and/or replace >22,500 square feet of impervious surface (collectively over the entire project site) in Watershed Management Zones 1 and 2 shall manage peak stormwater runoff to ensure that post-development peak flows, discharged from the site, do not exceed pre-project peak flows for the 2-through 10-year storm events and shall meet Water Quality Treatment and Runoff Item 8.k. - Page 56 Retention Performance Requirements. Reporting Requirements -For each Regulated Project subject to the Peak Management Performance Requirement a Stormwater Control Plan shall be required. Final project approval shall not be granted until the Stormwater Control Plan for the Regulated Project sufficiently demonstrates the Regulated Project design meets the Water Quality Treatment, Runoff Retention, and Peak Management Requirements. Performance Requirement S:Special Circumstances There are no Special Circumstances designation in the City of Arroyo Grande. Alternative Compliance The City will only consider alternative compliance for projects able to demonstration technical infeasibility and who cannot satisfy the 10% adjustment criteria on site. Alternative Compliance may be allowed under the following circumstances: 1. Technical Infeasibility -applicant must submit a site-specific hydrologic and/or design analysis conducted and endorsed by a registered professional engineer, geologist, architect, and/or landscape architect, demonstrating that compliance with the applicable numeric Post- Construction Stormwater Management Requirements is technically infeasible. 2. The Regulated Project applicant must submit a description of the project(s) that will provide off- site mitigation. The proposed off-site projects may be existing facilities and/or prospective projects that are as effective in maintaining watershed processes as implementation of the applicable Post-Construction Stormwater Requirements on-site. The description shall include: c) The location of the proposed off-site project(s) must be within the same watershed as the Regulated Project. Alternative Compliance project sites located outside the watershed may be approved by the Central Coast Water Board Executive Officer d) A schedule for completion of offsite mitigation project(s), where the off-site mitigation project(s) has not been constructed. Technical infeasibility may be caused by site conditions, including: a) Depth to seasonal high groundwater limits infiltration and/or prevents construction of sub- grade stormwater control measures b) Depth to an impervious layer such as bedrock limits infiltration c) Sites where soil types significantly limit infiltration d) Sites where pollutant mobilization in the soil or groundwater is a documented concern e) Space constraints (e.g., infill projects, some redevelopment projects, high density development) Item 8.k. - Page 57 f) Geotechnical hazards g) Storm water Control Measures located within 100 feet of a groundwater well used for drinking water h) Incompatibility with surrounding drainage system (e.g., project drains to an ex1stmg stormwater collection system whose elevation or location precludes connection to a properly functioning treatment or flow control facility). Operational and Maintenance Plans The developer shall submit an Operation and Maintenance Plan and Maintenance Agreements (O&M Plan) that clearly establish responsibility for all structural Water Quality Treatment, Runoff Retention, and/or Peak Management controls for all Regulated Projects. The Regulated Project applicant shall develop and implement a written O&M Plan. The O&M Plan shall be submitted for approval prior to fmal approval/occupancy. The O&M Plan must include: a. A site map identifying all structural Stormwater Control Measures (SCM's) requiring O&M practices to function as designed b. O&M procedures for each structural stormwater control measure including, but not limited to, LID facilities, retention/detention basins, and proprietorship devices. c. The O&M Plan will include short-and long-term maintenance requirements, recommended frequency of maintenance, and estimated cost for maintenance. Maintenance Agreement and Transfer of Responsibility for SCMs: Prior to issuing approval for final occupancy the owner of the Regulated Project subject to these Post-Construction Requirements shall provide verification of ongoing maintenance provisions for Structural Stormwater Control Measures, including but not limited to legal agreements, covenants, CEQA mitigation requirements, . and or conditional use permits. Verification shall include, at a minimum: a. The project owner's signed statement accepting responsibility for the O&M of the installed onsite and/or offsite structural treatment and flow control SCMs until such responsibility is legally transferred to another entity; and either i. A signed statement from the public entity assuming responsibility for structural treatment and flow control SCM maintenance and stating that the SCM meets all local agency design standards; or 11. Written conditions in the sales or lease agreements or deed for the project that require the buyer or lessee to assume responsibility for the O&M of the onsite and/or offsite structural treatment and flow control SCM until such responsibility is legally transferred to another entity; or 111. Written text in project deeds, or conditions, covenants and restrictions for multi-unit residential projects that require the homeowners association or, if there is no association, each individual owner to assume responsibility for the O&M of the onsite and/or offsite Item 8.k. - Page 58 structural treatment and flow control SCM until such responsibility is legally transferred to another entity; or iv. Any other legally enforceable agreement or mechanism, such as recordation in the property deed, that· assigns responsibility for the O&M of the onsite and/or offsite structural treatment and flow control SCM to the project owner(s). Reporting The Central Coast Regional Board requires two types of reporting. • Project applicant reporting to the City Applicants of regulated projects subject to Runoff Retention Requirement (PR 3) are required to demonstrate compliance with a decentralized approach to stormwater management through a Stormwater Control Plan. Additional supporting information is required if the project is subject to additional Performance Requirements. Determine Watershed Management Zones Projects creating or replacing 15,000 square feet or more of impervious surfaces, that are not a detached single family residence, and do not qualify for a special circumstance designation, will need to know their Watershed Management Zone (WMZ). Watershed management zones (WMZs) are based on common key watershed processes and receiving water type. They are the basis for determining if the project is subject to Runoff Retention Performance Standards, or Runoff Retention and Peak management Requirements Performance Standards. There are two Watershed Management Zones located within the City of Arroyo Grande. For a copy of the Watershed Management Zone map please visit the Engineer's office at City Hall. If the project is located on one or the two WMZs, the applicant shall satisfy the requirements of each zone proportionately. The City's Engineering Division can assist if the maps does not clearly identify the watershed management zone the project is located in. Determine Applicable Rainfall Event The performance criteria for post-construction retention standards is the percentile storm that best represents the volume that is fully infiltrated in a natural condition, and thus should be managed onsite to maintain the pre-development hydrology for duration, rate and volume of stormwater flows. The percentile rain event is the 95th percentile rain event and shall be achieved by infiltration, rainwater harvesting and/or evaporation for Watershed Management Zones 1 and 2. To obtain exhibits for the 8Sth and 951h percentile, 24-hour storm exhibits go to http://www.swrcb.ca.gov/rwqcb3 /water issues /programs /storm water /docs /lid/lid hydromod c harette index.shtml Item 8.k. - Page 59 Stormwater Control Plan (SWCP) Coversheet Owner/Engineer contact inform (as applicable) Name: --------------------------------- Mailing Address:---------------------------- Email Address: Phone number: ------------------------ Permit/Project Number: ______ _ Property APN: ---------- Impervious surface values: Pre-Project: Post-Project: Impervious Area (sf): Impervious Surface Area (sf): New(%): Total Project Site Area (ac): Replaced{%): Net Impervious Area (sf): Total Disturbed Area (ac): Applicable Performance Requirements o Performance Requirement 1: Site Design and Runoff Reduction o Performance Requirement 2: Water Quality Treatment o Performance Requirement 3: Runoff Retention o Performance Requirement 4: Peak Management o Performance Requirement S:Special Circumstances (select applicable special circumstance(s) from list below) _Highly Altered Channel _ Intermediate Flow Control Facility Historic Lake or Wetland _Technical Infeasibility: Equivalent Impervious Surface Area: _____ _ Identify appropriate certification statement being pursued: o (Full compliance) o (Partial compliance on-site) Location of off-site features: 0 (Alternative Compliance) -------------------- Certification statement must be seal and signed by a State of California licensed civil engineer. Item 8.k. - Page 60 Report Stormwater Control Plan (SWCP) Checklist o Cover Sheet. o Table of Contents. o Project type (commercial, industrial, multiunit residential, mixed use, public) and description. o Identify if project will be completed in phases, and if so, what phase is represented by the SWCP. o List of permits requested and other permits required (401, 404, Caltrans Encroachment, etc). o Table of Performance Requirements applicable to project and ifthere are any adjustments required. o Checklists from each applicable performance requirement or alternate compliance, as appropriate. o Site assessment summary (Step 2 and 3). Reference Site Stormwater Assessment Exhibit described below. o Summary of Site Design and Runoff Reduction, Water Quality Treatment, Runoff Reduction and Structural Stormwater Control Measures, by Drainage Management Area, as well as the entire site (as applicable to project). Reference Exhibits listed below. Identify types ofretention and non-retention based measures specified. o Supporting calculations to demonstrate compliance with applicable Performance Requirements. o Statements of Compliance. Exhibits o Drainage Management Area (OMA) Exhibit. o Uniquely identify each OMA and indicate if the OMA is self-retaining (zero discharge), self-treating, or draining to a treatment/flow control facility. o Include location of all infiltration, treatment, or flow-control facilities, their tributary area and basis for sizing (rational C, NRCS CN value, Tc, etc) o Potential pollutant source areas (if applicable), including loading docks, food service areas, refuse areas, outdoor processes and storage, vehicle cleaning, repair or maintenance, fuel dispensing, equipment washing, etc. o Plan Set with Construction Details for drainage related items (as appropriate) o Site Stormwater Assessment Exhibit. o Site map with (existing and proposed) topographic information o Delineation of sensitive areas, native vegetation and soils types. (Can be provided on multiple exhibits to supplement design strategy narrative) Item 8.k. - Page 61 Performance Requirement 1: Site Design and Runoff Reduction SWCP Checklist DESIGN STRATEGY MEANS OF DEMONSTRATING COMPLIANCE 1 Limit disturbance of creeks and natural drainage Pre and post drainage feature map. features. Delineate natural drainage features on Site Stormwater Assessment Exhibit and OMA Exhibit, as applicable. 2 Minimize compaction of highly permeable soils. Site Stormwater Assessment Exhibit of soil tvoes, overlain with development footorint 3 Limit clearing and grading of native vegetation Site Stormwater Assessment Exhibit with at the site to the minimum area needed to build native vegetation, overlain with development the project, allow access, and provide fire footprint. orotection. 4 Minimize impervious surfaces by concentrating Site Stormwater Assessment Exhibit with improvements on the least-sensitive portions of delineated sensitive areas overlain with the site, while leaving the remaining land in a development footprint natural undisturbed state. MINIMIZE STORMWATER RUNOFF BY IMPLEMENTING ONE OR MORE OF THE FOLLOWING DESIGN MEASURES: MANDATORY SITE DESIGN MEASURES Selected Reason, (SELECT AT LEAST ONE) for not selectino a. Roof runoff directed into cisterns or rain barrels for reuse? Roof runoff directed into vegetated areas b. (safely away from building foundations and footings)? 5 Runoff from sidewalks, walkways, and/or c. patios directed onto vegetated areas (safely away from the building foundations and footings)? Runoff from driveways and/or uncovered d. parking lots onto vegetated areas (safely away from the building foundations and footinos )? Are bike lanes, driveways, uncovered e. parking lots, sidewalks, walkways, and patios constructed with permeable surfaces? NOTE: This checklist must be included with every project application (except for projects deemed EXEMPT). See Figure xxx to determine if your project is considered exempt, or regulated. Item 8.k. - Page 62 Performance Requirement 2: Water Quality Treatment SWCP Checklist o Project Net Impervious Area o Certification that on-site water quality treatment measures have been met on site, or if not achievable: o Documentation of the volume of runoff for which compliance cannot be achieved on site and the associated off-site compliance requirements; o Statement of intent to comply with Water Quality Treatment Performance Requirement through Alternative Compliance. For each Drainage Management Area, provide: o Unique OMA Number, area, and likely pollutant(s) of concern o Water Quality Treatment Approach N/A if self-treating, or, Through the use of LID, Biofiltration or Non-retention Based Treatment System); o Supporting calculations demonstrating compliance with Treatment Performance Requirement; o Plan sheet page and detail number (if appropriate) of Drainage Management Areas (OMA) Exhibit where construction details are provided for each OMA. For DMAs using Low Impact Development Treatment Systems, provide: o 85th percentile 24-hour storm event value, and basis of determination. For DMAs using Biofiltration Systems, provide: o Statement indicating why an LID treatment system was not appropriate; o Surface loading rate approach, and basis of determination;- (0.2 x per hour intensity, or 2 x 85th percentile hourly rainfall intensity); o Calculations to demonstrate that the minimum surface reservoir volume is equal to the biofiltration treatment system surface area time a depth of 6-inches; o Construction detail (or reference to page on plans) which provides: o Minimum planting depth o Planting medium specifications. Either: • Specify 60 to 70% ASTM C33 sand, with 30-40% compost , or • Provide testing documentation demonstrating planting medium specified can minimally infiltrate at a rate of 5 inches per hour) o Plant selection consistent with Appendix L; o Subsurface drainage/storage (gravel) layer with an area equal to the biofiltration treatment system surface area and having a minimum depth of 12 inches; o Underdrain with discharge elevation at top of gravel layer; o No compaction of soils beneath the biofiltration facility (ripping/loosening of soils required if compacted); o No liners or other barriers interfering with infiltration, except for situations where lateral infiltration is not technically feasible. For DMAs using Non-Retention Based Treatment Systems, provide: o Statement indicating why an LID, or Biofiltration treatment system was not appropriate o Hydraulic Sizing Criteria used, and basis of determination (Volume = to 85th percentile, 24-hour storm, or flow basis (2 x 85th percentile hourly rainfall intensity or 0.2 x inches per hour intensity) Item 8.k. - Page 63 Performance Requirement 3: Runoff Retention SWCP Checklist SITE ASSESSMENT MEASURES: (see table 3.5) Include an exhibit and narrative of the opportunities and constraints to implementing LID Stormwater Control measures based on the following items (as applicable): D Site topography D Run-on characteristics (source and estimated runoff from offsite which discharges to the project area) D Hydrologic features including contiguous natural areas, wetlands, watercourses, seeps, D Existing drainage infrastructure for the site and nearby or springs areas, including the location of municipal storm drains D Depth to seasonal high groundwater D Structures, including retaining walls D Locations of groundwater wells used for D Utilities drinking water D Easements D Depth to an impervious layer such as Bedrock D Covenants D Presence of unique geology (e.g., karst) D Zoning/Land Use D Geotechnical hazards D Setbacks D Documented soil and/or groundwater D Open space requirements Contamination D Other pertinent overlay(s) D Soil types and hydrologic soil groups D Vegetative cover/trees SITE DESIGN MEASURES Include in narrative, and provide supporting exhibits as necessary, to demonstrate that the project design has implemented the following design strategies (as applicable) DESIGN STRATEGY MEANS OF DEMONSTRATING COMPLIANCE Define the development envelope and protected Site Stormwater Assessment Exhibit. areas, identifying areas that are most suitable for 1. development and areas to be left undisturbed. Conserve natural areas, including existing trees, Site Stormwater Assessment Exhibit with native vegetation, 2. other vegetation, and soils overlain with development footprint Limit the overall impervious footprint of the Discussion regarding other building configurations 3. project considered (and ultimately rejected) Construct streets, sidewalks, or parking lot aisles Discussion on minimum allowable widths, and rationale for to the minimum widths necessary, provided that using larger values (if applicable) or confirmation that 4. public safety or mobility uses are not minimum values were used (where applicable). compromised Set back development from creeks, wetlands, Discussion on set-back dimensions chosen. 5. and riparian habitats Conform the site layout along natural landforms Within the Drainage Management Area (OMA) Exhibit, show Topo survey with existing and planned contours cut and fill 6. lines. Discussion of grading approach. Avoid excessive grading and disturbance of Exhibit with native vegetation, overlain with planned 7. vegetation and soils disturbed area limits. Item 8.k. - Page 64 Performance Requirement 3: Runoff Retention SWCP Checklist Continued STORMWATER STRUCTURAL CONTROL MEASURE SIZING For Overall project, o Certification statement indicating that the selection, sizing, and design of Stormwater Control measures meets the applicable Water Quality Treatment and Runoff Retention Performance Requirements, or, if not achievable o Provide documentation of the volume of runoff for which compliance cannot be achieved on-site and the associated off-site compliance volume o Statement of intent to comply with Water Quality Treatment and Runoff Retention Performance Requirements through an Alternative Compliance Agreement o Documentation demonstrating percentage of the project's Equivalent Impervious Surface Area dedicated to retention-based Stormwater Control Measures For each OMA, o Indicate sizing strategy used o Hydrologic analysis and sizing methods o Locally/regionally calibrated continuous simulation model that results in equivalent optimization of on-site runoff retention volumes o Hydrologic analysis and sizing methods, equally effective in optimizing on-site retention volumes of the runoff generated by the rainfall events specified o Provide supporting calculations demonstrating compliance with Runoff Retention Performance Requirement o Indicate if a ten percent adjustment (based on technical infeasibility) is included in design approach o Indicate if off-site mitigation is included in design approach NOTE: This checklist must be included with every project application (except for projects deemed EXEMPT). See Figure xxx to determine if your project is considered exempt, or regulated. Item 8.k. - Page 65 Performance Requirement 4: Peak Management SWCP Checklist Project Level Documentation, identify o Point source discharge locations o Hydraulic Report demonstrating that post development storm water runoff peak flows discharged from the site do not exceed pre-project peak flows for the 2-through 10-yer storm events) o Certification that on-site water quality treatment measures have been met on site, or if not achievable: o Documentation of the volume of runoff for which compliance cannot be achieved on site and the associated off-site compliance requirements o Statement of intent to comply with Water Quality Treatment Performance Requirement through Alternative Compliance NOTE: This checklist must be included with every project application (except for projects deemed EXEMPT). See Figure xxx to determine if your project is considered exempt, or regulated. Item 8.k. - Page 66 Performance Requirement 5: Special Circumstances SWCP Checklist Project Level Documentation, identify D Which types of Special Circumstances apply D Which Watershed Management Zones (WMZ) the project is located in D Identification if the project is located atop of a designated Groundwater Basin D Proposed Performance Requirement modifications based on special circumstances o Peak Management o Runoff Retention For highly altered channels, D Vicinity map indicating channel location relative to project, and downstream receiving waters D Narrative, and supporting calculations (as applicable) regarding anticipated impacts to downstream waters For intermediate flow control facilities, D Vicinity map indicating location of intermediate flow control facilities relative to project, and downstream receiving waters D Quantification of pre-project tributary area to intermediate flow control facility performance D Quantification of proposed post-project tributary area to intermediate flow control facility Performance D Summarize flow control performance data (pre and post) and include supporting performance information based on numeric, hydraulic modeling, including flow volumes, durations and velocities D Narrative, and supporting calculations (as applicable) regarding anticipated impacts to downstream Waters D Vicinity map delineating location of historic lake and/or wetlands relative to project D Supporting technical information to substantiate the request D Narrative, and supporting calculations (as applicable) regarding anticipated impacts to downstream Waters D Stamped submittal (by registered professional engineer, geologist, architect, and/or landscape architect) NOTE: This checklist must be included with every project application (except for projects deemed EXEMPT). See Figure 1 to determine if your project is considered exempt, or regulated. Item 8.k. - Page 67 Alternate Compliance (Off-Site Compliance) SWCP Checklist The City will only consider alternative compliance for projects able to demonstrate technical infeasibility. Projects approved for alternative compliance must identify and secure rights to use an alternative site. Potential off-site compliance alternative projects might include green streets retrofits, off-site drainage features, riparian habitat restoration projects, etc. The off-site compliance alternative project must be located within the same watershed as the project and retain the storm water retention volume required by the original project. It is recommended that discussions with City staff begin early in the development process regarding the acceptability of an off-site compliance alternative project. Project Level Documentation, identify o Indication of site conditions which are resulting in LID technical infeasibility o Depth to seasonable high groundwater limits infiltration and/or prevents construction of subgrade stormwater control measures o Depth to an impervious layer such as bedrock limits infiltration o Sites where soil types significantly limit infiltration o Sites where pollutant mobilization in the soil or groundwater is a documented concern o Space constraints (e.g., infill projects, some redevelopment projects, high density development) o Geotechnical hazards o Stormwater Control Measures located within 100 feet of a groundwater well used for drinking water o Incompatibility with surrounding drainage system (e.g., project drains to an existing stormwater collection system whose elevation or location precludes connection to a properly functioning treatment or flow control facility) o Indication of site conditions which are resulting in Bioretention technical infeasibility o Biofiltration is not compatible with surrounding drainage system o Location available for biofiltration facility is in an area with identified erosion or landslide hazards o Location available for biofiltration facility is on a slope equal to or in excess of 8 percent o Location available for biofiltration facility is within 50-feet from the projected top of the slope (using projected angle of repose) that is great than 20% o Areas where runoff potentially contains industrial wastes o Areas where there is a higher risk of concentrated spills (such as gas stations, truck stops) o Site-specific hydrologic and/or design analysis conducted and endorsed by a registered professional engineer, geologist, architect, and/or landscape architect, demonstrating that compliance with the applicable numeric Post- Construction Stormwater Management requirements is technically infeasible. o Schedule for completion of offsite project with milestone dates to identify funding, design, and construction of the off-site project(s) Note, Approved Watershed or Regional Plans, and projects situated within designated Urban Sustainability Areas are currently not acceptable reasons for pursuing off-site compliance NOTE: This checklist must be included with every project application (except for projects deemed EXEMPT). See Figure xxx to determine if your project is considered exempt, or regulated. Item 8.k. - Page 68