CC 2016-02-09_12a Drainage Assessment and Replacement Report
MEMORANDUM
TO: CITY COUNCIL
FROM: GEOFF ENGLISH, PUBLIC WORKS DIRECTOR
MATT HORN, CITY ENGINEER
SUBJECT: DRAINAGE INFRASTRUCTURE ASSESSMENT AND REPLACEMENT
REPORT
DATE: FEBRUARY 9, 2016
RECOMMENDATION:
It is recommended the City Council receive and provide comments and direction on the
draft Drainage Infrastructure Assessment and Replacement Report.
IMPACT ON FINANCIAL AND PERSONNEL RESOURCES:
No financial impact at this time. Information assembled in this report will assist in
prioritizing funding requests for the development of future budget recommendations.
BACKGROUND:
During the development of the Fiscal Year 2015-2017 Biennial Budget, the Public
Works Department submitted a budget request for $25,000 from the City’s Sales Tax
Fund to cover the cost for unspecified equipment and infrastructure replacement and
repairs for drainage facilities. The line item request was titled Various Stormwater,
Drainage and CMP Improvements. In past budget cycles, the Public Works Department
has made similar budget requests which were then subsequently used to complete
needed and/or urgent drainage repair and replacement projects. At the special City
Council Budget hearing for Capital Improvement Projects and Non-General Fund
Programs held on May 12, 2015, the Council requested a list of specific requests in lieu
of the unspecified budget requests for drainage improvements. In addition, the City
Council requested a list of specific infrastructure replacement projects for parks,
government building and ADA improvements.
As a result of this direction, an inventory and assessment of the condition of the City’s
General Fund supported infrastructure and assets in the following general categories is
being conducted:
• Parks, Landscaping and Open Space
• Government Buildings
• Drainage Facilities
• Sidewalks and Pedestrian bridges
• Roads
Item 12.a. - Page 1
CITY COUNCIL
DRAINAGE INFRASTRUCTURE ASSESSMENT AND REPLACEMENT REPORT
FEBRUARY 9, 2016
PAGE 2
Similar infrastructure assessment reports for Government Buildings and the City’s
Parks, Landscaping and Open Space have been previously presented to Council.
Following are the general findings of the two previous infrastructure assessment
reports:
City’s Parks, Landscaping and Open Space system:
• Approximate replacement cost for existing infrastructure: $ 4,900,000
• Approximate annual depreciation and replacement costs: $ 210,000
Government Buildings:
• Approximate replacement cost for existing infrastructure: $ 4,700,000
• Approximate annual depreciation and replacement costs: $ 121,000
The final assessment reports and lifetime replacement schedules in this series will focus
on sidewalks, pedestrian bridge facilities, and roads.
ANALYSIS OF ISSUES:
One of our most critical infrastructure systems is the storm drainage system, which is
often referred to as the Storm Sewer System; however the City storm drain system
drains to basins and creeks and not to the sanitary sewer system. The storm drain
system is designed to convey stormwater runoff through engineered conveyance
systems (pipes and open channels) into detention basins and natural creeks. The City
owns and maintains approximately 20.7 miles of storm drain pipe, made up of pipes of
various types and sizes. Below is a summary of the storm drain pipes in the drainage
system.
Pipe Type Abbreviation Miles
Corrugated Metal Pipe CMP 2.57
High-density polyethylene pipe HDPE 5.43
Polyvinyl chloride pipe PVC 3.38
Reinforced Concrete pipe RCP 9.38
TOTAL MILES 20.7
The storm drain conveyance systems have an industry standard life span which varies
based on the durability of the type of manufactured material. The approximate life
expectancy for each type of storm drain pipe is listed below. Also listed below is a
recommended replacement cycle for the purposes of determining the amortized
replacement costs.
Pipe Type Life expectancy Replacement Cycle
CMP 25 years 50 years
HDPE 100 years 200 years
PVC 100 years 200 years
RCP 100 years 200 years
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CITY COUNCIL
DRAINAGE INFRASTRUCTURE ASSESSMENT AND REPLACEMENT REPORT
FEBRUARY 9, 2016
PAGE 3
Below is a pie chart showing the relative percentage of pipe type that make up the City’s
storm drain system.
Fortunately, a significant percentage of the storm drain pipe consists of durable
products with a long life expectancy. Of primary concern is the approximately 2.5 miles
of Corrugated Metal Pipe (CMP) which has a relatively short life span. A significant
portion of the CMP in the ground in Arroyo Grande was installed before 1990, therefore
much of this type of pipe is at or beyond its recommended life cycle. CMP is prone to
corrosion and failure, and two previous CMP failures in Arroyo Grande resulted in
significant road failure incidents.
For the purpose of indentifying the cost of drainage system asset replacement, the
following two methods for data collection and asset inventory were used:
• Field data collection and asset evaluation: A field inspection was conducted to
evaluate the condition of all CMP segments in the City. A specialized camera
device, borrowed from another agency, was used to conduct visual below-ground
inspections. The overall condition of the individual pipe segments was quantified
through a rating system. Six CMP pipe segments were found to be in partially
failing condition; however, none of these pipes appeared to be at risk of imminent
failure. A replacement plan and funding request will be submitted for the
replacement of specific CMP segments in the next fiscal year budget process.
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CITY COUNCIL
DRAINAGE INFRASTRUCTURE ASSESSMENT AND REPLACEMENT REPORT
FEBRUARY 9, 2016
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• Storm Drain System Atlas data: A Storm Drain Atlas was prepared in 2008 that
quantified and mapped the City’s storm drain system at that time. Information
about the remaining underground storm water conveyance pipes was generated
from this document and translated into the asset inventory for this report. A
future project to videotape and conduct a visual analysis of this additional
infrastructure would be prudent, but not recommended at this time.
In addition to the asset types listed above, the storm drain system also includes drain
inlets which were included in the asset replacement report. Drain inlets (DI’s) are a
metal and concrete structure usually at the road edge curb face that conveys storm
water runoff from the curb into the storm drain pipes.
Open channels and stormwater detention basins in the storm drain system require
funding for maintenance and operation improvements; however, that information is not
included in the scope of this report.
ASSET REPLACEMENT COSTS
Estimated replacement cost for the various drainage facility types is listed in the table
below, along with a conservative recommended replacement cycle:
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CITY COUNCIL
DRAINAGE INFRASTRUCTURE ASSESSMENT AND REPLACEMENT REPORT
FEBRUARY 9, 2016
PAGE 5
Below is the approximate value of the elements of the City’s drainage system and the
amount of funding that would be needed to maintain these assets based on the
determined replacement cycle.
• Approximate replacement cost for existing infrastructure: $ 3,360,000
• Annual depreciations and replacement costs: $ 238,107
Funding is not being requested at this time for any specific drainage projects. The
information has been collected to help provide prioritized drainage project
recommendations to the City Council during budget development in the next fiscal year
cycle. This information can also be used comparatively by the City Council when
determining funding requirements for other asset replacement projects.
ALTERNATIVES:
The following alternatives are provided for City Council consideration:
1. Receive and provide comments and direction on the Drainage Infrastructure
Assessment and Replacement Report; or
2. Provide other direction.
ADVANTAGES:
The preparation of the Drainage Infrastructure Assessment and Replacement Report
will provide the Council with cost estimates and fiscal analysis of the City’s deferred
maintenance liabilities that will be useful in determination of future funding allocations.
In addition, the assessment of the condition of the various storm drain infrastructure
provides the Council with a list of prioritized drainage projects.
DISADVANTAGES:
Currently no funds are being set aside for drainage system asset replacement.
Additionally, funding of drainage infrastructure replacement will compete with other
asset replacement projects for parks, buildings, sidewalks and roads.
ENVIRONMENTAL REVIEW:
Not applicable.
PUBLIC NOTIFICATION AND COMMENTS:
The Agenda was posted in front of City Hall on Thursday, February 4, 2016 and the
Agenda and staff report were posted on the City’s website on Friday, February 5, 2016.
ATTACHMENT:
1. CMP Inventory and Evaluation
Item 12.a. - Page 5
CMP INVENTORY AND EVALUATION .. 12120115
'.Pipe Type· Size (in) Length (ft) INDEX ~OCATION •RATING -!
CMP 42 282.279 03 HUASNA RO/ ORO DR 2: PARTIALLY FAILING
CMP 36 184.732 D2 UNDER CHEVRON ON W BRANCH 2: PARTIALLY FAILING
CMP 30 634.212 Bl,Cl 900 BLK OAK PARK BLVD 2: PARTIALL V FAILING
CMP 24 646373 C3, 03 ORO DR 2: PARTIALLY FAILING
CMP 24 39.173 C3 312 TA~LY HO RD 2: PARTIALLY FAILING
CMP 8 349.876 E2 S RENA ST/ S ALPINE ST 2: PARTIALLY FAILING
CMP 18 118.362 03,03 LAUNA LN 3: PARTIALLY FAILING
CMP 43 69.819 Bl EQUESTRIAN WAY/ NOYES RD 4: B_EGIN FAILING_COND.
CMP 43 68.299 Bl EQUESTRIAN WAY/ NOYES RD 4: BEGIN FAILING COND.
CMP 43 68.614 81 EQUESTRIAN' WAY/ NOYES RD 4: BEGIN FAILING COND.
CMP 43 ---81 EQUESTRIAN WAY/ NOYES RD 4: BEGIN FAILING COND. 68.795
CMP 43 68.015 Bl EQUESTRIAN WAY/ NOYES RD 4: BEGIN FAILING COND.
CMP 24 79.504 Cl OAK PARK BLVD/ W BRANCH ST DRAINAGE BASIN 4: BEG.IN FAILING COND.
CMP 24 25.715 Cl KENNEDY CLUB DRAINAGE 4: BEGIN FAILING COND.
CMP 18 110.194 Fl ALDER ST/ CAMERON CT 4: BEGIN FAILING COND.
CMP 18 19.143 F2 BAMBI tr 4: BEGIN FAILING CONO.
CMP 18 lP&-~87 E2 TAYLOR PL 4: BEGIN FAILING COND.
CMP 18 279.717 Bl DEER TRAIL CR 4:_ BEGIN FAILING COND.
CMP 18 67.295 Cl JAMES WAY/ LEISU.RE DR 4: BEGIN FAILING COND.
CMP 16 398.410 El E GRAND AVE/ ALDER ST I SUNSET OR 4: BEGIN FAILING COND.
CMP 16 72.987 El E GRAND AVE/ ALDER ST/ SUNSET DR 4: BEGIN FAILIN'G COND.
CMP 12 91.610 C2 VIA LA BARRANCA DRAINAGE 4: BEGIN FAILING CONO.
CMP 12 33.574 01 MONTEGO ST (OCEAN VIEW ELEM) 4: BEGIN FAILING COND.
CMP 30 83.391 B1,C1 900 BLK OAK PARK BLVD 6: LOSS OF GALIVINIZATION
CMP 54 57.991 C3 TALLY HO RD/ PRINTZ RO 6: LOSS OF GALV. & SILTED
CMP 54 60.775 C3 TALLY HO RD/ PRINTZ RD ' 6: LOSS OF GALV. & SILTED
CMP 72 90.100 Bl NOYES RO 6: LOSS OF GALVANIZATION
CMP 72 86.443 Bl NOYES RD 6: LOSS OF GALVANIZATION
C:MP 24 38.835 02 STATION WAY/ POST OFFICE 6! LOSS OF GALVANIZATION
CMP 18 25.845 01 BRIGHTON AVf. / FAIRVIEW DR 6: LOSS OF GALVANIZATION
ATTACHMENT 1
Item 12.a. - Page 6
CMP 18 153.313 E2 EMANCT 6: LOSS OF GALVANIZATION
CMP 18 188.745 C3 ORO DR TO TERRA OE ORO DRAINAGE BASIN 6: LOSS OF GALVANIZATJON
CMP 18 120.452 C3 TOYON PL 6: LOSS OF GALVANIZATION
CMP 18 121.190 04 STROTHER PARK 6; LOSS OF GALVANIZATION
CMP 18, 157.674 F2 TURQUOISE OR 6: LOSS OF'GALVANIZATION
CMP 18 146.822 F2 PEARL DR 6: LOSS OF GALVANIZATION
CMP 14 20.100 02 SHORT ST 6: LOSS OF GALVANIZATION
CMP 48 325.660 El SOTO FIELDS BASIN l TO BASIN 2 6: LOSS OF GALVINAZATION
CMP 72 111.353 Cl JAMES WAY (BRIDGE) 7: SOME GALVANIZATION LOSS
CMP 72 111.441 Cl JAMES WAY {8_RIDGE)' 7: SOME GALVANIZATION LOSS
CMP 72 112.000 Cl JAMES WAY {BRIDGE) 7: SOME GALVANIZATION LOSS
CMP 36 181.962 E.2,03 . ORCHARD AVE/ PILGRIM WAY 7: SOME GALVANIZATION LOSS
CMP '36 51.786 El SOTO Fl-ELDS-BASIN 2 TO BASIN 3 / BAKE MAN lN 7: SOME GALVANIZATION LOSS
CMP 30 17.402 C2 JAMES WAY I GRACE BIBLE/ RANCHO GRANDE 7: SOME GALVANIZATl.ON LOSS
CMP 24 229.955 F2 WOODLAND DR/ WOODLAND CT 7: SOME GALVANIZATION LOSS
CMP 24 65._529 03 TRAFFIC WAY/ CHERRY AVE 7: SOME GALVANIZATION LOSS
CMP 24 140.182 ACORN DR 7: SOME GALVANIZATIOl')l LOSS
CMP 24 108.162 WOODLAND DR 7: SOME GALVANIZATION LOSS
CMP 24 75.99'1 02 OLOHAN ALY (MIDDt.E} 7: SOME GALVANIZATION LOSS
CMP 18 59.169 E2 500 BU<. FAIR OAKS AVE 7: SOME' GALVANIZATION LOSS
CMP 18 40.341 Cl JAMES WAY (BRIDGE) 7:SOME GALVANIZATION LOSS
CMP 18 18~.488 Cl ACORN DR/ ACROSS JAMES WAY 7: SOME GALVANIZATION LOSS
CMP 18 37.357 C3 GUILARTE RD/ COBRE Pl 7: SOME GALVANIZATION LOSS
CMP 18 36.000 Cl JAMES WAY (BRIDGE) 7: SOME GALVANIZATION LOSS
CMP 18 54.3~7 Cl JAMES WAY (BRIO.GE) 7: SOME GALVANIZATION LOSS
CMP 18 42.5.15 Cl JAMES WAY /LEISURE DR 7: SOME GALVANIZATION LOSS
CMP 18 12,728 C3 TALLY HO /VIA LA BARRANCA 7: S_OME GALVANIZATION LOSS
CMP 18 39.316 C3,D3 PASEO ST I MAY ST 7: SOME GALVANIZATION LOSS
CMP 12 37.006 03 SMASONST 7:_SOME GALVANIZATION LOSS
CMP 12 38.396 03 SMASONST 7; SOM(GALVANIZATION LOSS
(:MP 8 12.453 E2· CERRO VIST4 lN 7:,SOME GALVANIZATION LOSS
CMP 0 26.116 02 E GRAN-DAVE/ SB HWY 101 OFF-RAMP/ ARCO 7: SOME G-ALVANJZATION LOSS
CMP 24 63.469 04 COACH RD/ BRANCH M_ILL RD 8: GOOD COND.
CMP 18 46.651 01 POPLAR ST/ POPLAR BASIN 8: GOOD COND.
Item 12.a. - Page 7
CMP 36 380.248 Cl OAK PARK BLVD BEHIND BEST WESTERN 9': GOOD COND.
CMP 18 305.960 E2 CERRO VISTA LN 10: LOOKS NEW
CMP 24 lSS.288 Fl S ELM ST/ S ELM DRAINAGE BASIN ALREADY BEING REPLACED
CMP 18 101.360 81 NOYES RD COUNTY
CMP 18 184.474 €3 PLOMOCT UNKNOWN COND. DI STUCK
CMP 24 91.778 Cl ACORN DR /ACROSS JAMES WAY UNKNOWN COND. INACCESSIBLE
CMP 18 326.512 f 2 WOODLAND OR/ WO,ODLAND CT UNKNOWN COND: INACCIESSIBLE
CMP 8 112.787 E2 NEWMAN DR UNKNOWN COND. INACCESSIBLE
CMP 36 79.618 04 FLORA RD/ ACROSS A(; CREEK FROM STROTHER UNKNOWN COND. SILTED
CMP 24 1~5.207 C3 312·TALLYHO RD UNKNOWN COND. UNDER WATE.R
CMP 18 25.845 01 BRIGHTON AVE/ FAIRViEW DR UNKNOWN COND. UNDER WATER
CMP 12 49.482 01 MONTEGO $T (OCEAN VIEW ELEM) UNKNOWN COND. UNDER WATER
CMP '18 74.338 03 HARRISON .st I tt>RBETf CANYON RD UNKNWON COND. INACCES.SIBLE
Item 12.a. - Page 8