CC 2021-10-26_08i Monthly Water Supply and Demand Update_September
MEMORANDUM
TO: CITY COUNCIL
FROM: BILL ROBESON, ASSISTANT CITY MANAGER/PUBLIC WORKS
DIRECTOR
BY: SHANE TAYLOR, UTILITIES MANAGER
SUBJECT: MONTHLY WATER SUPPLY AND DEMAND UPDATE
DATE: OCTOBER 26, 2021
SUMMARY OF ACTION:
Receive a report of the City’s water supply and demand for September 2021, including
current and projected Lopez Lake levels.
IMPACT ON FINANCIAL AND PERSONNEL RESOURCES:
Approximately two (2) hours of staff time is required to prepare the report.
RECOMMENDATION:
It is recommended the City Council receive and file the Monthly Water Supply and
Demand Report.
BAC KGROUND:
On April 25, 2017, the City Council, by Resolution, rescinded the previous Stage 1 Water
Shortage Emergency along with related emergency water conservation measures and
restrictions. During that public meeting, Council requested that staff continue preparing
the monthly water supply and demand updates. Council urged citizens to continue to
practice everyday water saving measures, and reiterated that the previously adopted
water conservation measures were to remain in effect.
In response to Council discussion on April 27, 2021, staff has begun to provide notice to
customers in non-compliance of the mandatory water conservation measures by hanging
door tags. In addition, four social media posts have been posted to the City’s social media
channels reminding customers of the measures, information is highlighted on the City’s
website, and message boards displaying conservation messaging have been placed at
various locations around the City. The City’s drought response team has continued to
enhance public awareness of the drought and has been preparing for upcoming water
shortage measures.
Item 8.i. - Page 1
CITY COUNCIL
MONTHLY WATER SUPPLY AND DEMAND UPDATE
OCTOBER 26, 2021
PAGE 2
On October 12, 2021, the City Council adopted a Resolution declaring a Stage 1 Water
Shortage Emergency, and implementing reductions in water usage as provided in Arroyo
Grande Municipal Code Section 13.07.030(A).
In September 2021, the City’s water use was 202.0 acre-feet with a per capita use of 124
gallons per day/per person. There was no measurable rainfall in September 2021. The
water use for the current “rolling” water year from October 2020 to September 2021 was
2,378.9 acre-feet which equates to a per capita use of 120 gallons per day per person.
There was a total of 9.11 inches of rain fall for this period.
ANALYSIS OF ISSUES:
The United States Drought Monitor, as of October 15, 2021, shows San Luis Obispo
County in an extreme drought. Rainfall to date for the period July 1, 2021, through October
15, 2021, is 0.0 inches at the Corporation Yard rain gauge. Lopez Lake, as of October
15, 2021, is at 30.3% capacity (14,950 acre-feet of storage).
The new water began on April 1, 2021, and the City’s annual Lopez contract supply was
2,290 acre-feet. On August 24, 2021, the San Luis Obispo County Board of Supervisors
(Board) enacted the Low Reservoir Response Plan (LRRP) for Lopez Lake. On
September 8, 2021, the Zone III Technical Advisory Committee endorsed the action of
reducing contract deliveries by 10%. The City began reducing the flow of Lopez Lake
deliveries on September 15, 2021, to 1.9 million gallons per day, compared to the normal
flow of 2.2 million gallons per day. In addition, the City has 1,323 acre-feet of ground
water entitlement from the Santa Maria Basin, and wells within the Pismo Formation that
produce approximately 160 acre-feet per year. The fourth quarter monitoring for the Santa
Maria Basin sentry wells was completed in October. The deep well index was 6.64 feet
above sea level, which is 0.86 feet lower than the deep well index threshold value of 7.5
feet and 0.43 feet lower than the index value one year ago (7.07 feet). This is the second
consecutive quarter the index is below the 7.5-foot threshold. If the deep well index value
is below 7.5’ for six (6) continuous quarters, this is also a Stage 1 triggering condition.
The projected water use for the City of Arroyo Grande for water year 2021/22 is 2,450
acre-feet based on current rainfall.
ADVAN TAGES:
This report provides the City Council and the public with the current and projected
conditions of our water supply and demand.
DISADVANTAGES:
No disadvantages noted at this time.
ALTERNATIVES:
Not applicable at this time.
Item 8.i. - Page 2
CITY COUNCIL
MONTHLY WATER SUPPLY AND DEMAND UPDATE
OCTOBER 26, 2021
PAGE 3
ENVIRONMENTAL REVIEW:
No environmental review is required for this item.
PUBLIC NOTIFICATION AND COMMENTS:
The Agenda was posted at City Hall and on the City’s website in accordance with
Government Code Section 54954.2.
Attachments:
1.Lopez Monthly Operations Report for September 2021
1.a. Lopez Monthly Operations Report for March 2020
2.Lopez Reservoir Storage Projection
3. Monthly Water Use Comparison
4.Monthly Monitoring Report for September 2021
Item 8.i. - Page 3
San Luis Obispo County Flood Control and Water District
Zone 3 - Lopez Project - Monthly Operations Report
September, 2021
0.00
Note: Deliveries are in acre feet. One acre foot = 325, 850 gallons or 43, 560 cubic feet. Safe yield is 8,730
acre feet.
"Year to Date" is January to present for State water, April to present for Lopez deliveries, and July to present for rainfall.
1186.98
April to Present
0.04
Arroyo Grande 2061
Lopez Dam Operations
Lake Elevation (full at 522.37 feet)469.5
Storage (full at 49200 acre feet)15208
Rainfall 0
Downstream Release (4200 acre feet/year)366.43
Spillage (acre feet)0
This Month Year to Date
1643.15
0.00
807.00 185.10
Entl.Surplus
Water
Declared Usage
2868
Total
Available
Water
Lopez Water Deliveries
0.00Oceano CSD 272.7 107.00 0.00380
396.13Grover Beach 720 282.00 64.601002
46.13Pismo Beach 802.8 314.00 0.001117
44.68CSA 12 220.5 86.00 6.97307
902.021260116.36
70.83968.07
346.6764043.43
State Water Deliveries
1673.9240771596.00 256.675673 1420.582116177.03Total
Contractor
Difference (feet)-52.87
% Full 30.9%
Comments:
1) Oceano supplied water to Canyon Crest via Arroyo Grande's Edna turn out. A total of 2.23 AF delivered to Canyon Crest was added
to Oceano's water usage this month and 2.23 AF was subtracted from Arroyo Grande's usage this month.
2) On May 12, 2021 Pismo requested to take all SW for April 2021. On May 18th, PB's SW Delivery Request was changed to 1260 AF.
3) Lopez Water Deliveries are now operated under the Low Reservoir Response Plan (LRRP). In August 2021 TAC requested a 10%
entitlement reduction (retroactive to April 2021) in anticipation of reaching the 15,000 AF trigger of the LRRP. Entitlements shown
represent a 10% reduction.
Surplus water shown is actually "Carry Over" water as designated in the LRRP.
April to Present Lopez Entitlement+Surplus Water Usage
0
50
100
150
200
250
Jan '21 Feb '21 Mar '21 Apr '21 May '21 Jun '21 Jul '21 Aug '21 Sep '21Acre FeetAG GB OCSD PB CSA12
January to Present State Water Usage
0
20
40
60
80
100
120
140
160
180
200
Jan '21 Feb '21 Mar '21 Apr '21 May '21 Jun '21 Jul '21 Aug '21 Sep '21Acre FeetOCSD PB CSA12 SanMig
San Miguelito 101.061209.17
This Month
%
Total
January to Present
Usage
This Month
% of
Annual
Request
Usage % of Annual
Request
185.1
Total Water
Deliveries
This Month
43.43
64.6
116.36
15.04
9.17
433.70
Annual
Request
0.00
Usage
0.00
0.00
0.00
0.00
%
0.00
0.00
0.00
0.00
0.00
1186.98
0.00
396.13
46.13
44.68
1673.920.00 1335.00
SWP
Deliveries
SWP
Deliveries
Change in
Storage
271 93.97
1180.58This Month Stored State Water
0.0%
9.0%41.4%
0.0%0.0%
9.0%39.5%
0.0%4.1%
3.2%14.6%
9.2%71.6%
8.4%73.8%
6.8%54.2%
6.3%29.5%8.4%67.1%
7.6%84.2%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
57.6%
0.0%
55.0%
5.7%
20.3%
41.1%0.0%
Entitlement Surplus
Usage %Usage %
Entitlement Surplus
Usage %
1086.61Last Month Stored State Water
Surplus
Requested
807.00
107.00
282.00
314.00
86.00
1596.00
Friday, October 8, 2021 Page 1 of 1Report printed by:AdminData entered by:D. Bravo
Attachment 1
Item 8.i. - Page 4
San Luis Obispo County Flood Control and Water DistrictZone 3 - Lopez Project - Monthly Operations ReportMarch, 2020727.00Note: Deliveries are in acre feet. One acre foot = 325, 850 gallons or 43, 560 cubic feet. Safe yield is 8,730 acre feet."Year to Date" is January to present for State water, April to present for Lopez deliveries, and July to present for rainfall.2122.35April to Present14.31Arroyo Grande2290Lopez Dam OperationsLake Elevation (full at 522.37 feet)490.87Storage (full at 49200 acre feet)25472Rainfall5.37Downstream Release (4200 acre feet/year)207.46Spillage (acre feet)0This MonthYear to Date2736.220.00378.00139.74Entl.Surplus Water DeclaredUsage2290.00Total Available WaterLopez Water Deliveries624.35Oceano CSD30350.000.00624.35787.22Grover Beach800132.0064.00820.001297.65Pismo Beach892147.000.001297.6586.34CSA 1224540.007.19245.0097.27112023.845.92272.040.002270.00State Water Deliveries4917.914530747.00210.935277.00132.28150135.14Total ContractorDifference (feet)-31.50% Full51.8%Comments:Available Surplus Water is shown and as designated per BOS May 14, 2019 Declaration of Surplus Water. Beginning with July 2019 report, Surplus Water Requested is amount purchased by each agency. Surplus Water used is based on Surplus Water Requested. 1) Oceano supplied water to Canyon Crest via Arroyo Grande's Edna turn out. A total of 1.5 AF delivered to Canyon Crest wasadded to Oceano's water usage this month and 1.5 AF was subtracted from Arroyo Grande's usage this month.On 2/7/2020 Pismo requested the remaining 127 AF of surplus water (SurW) in addition up to 90 AF of Oceano’s SurW if needed for March, 2020. In March, Pismo used 78.65 AF of Oceano's remaining SurW. Pismo Surplus = 200 AF (original) + 127AF (Total remaining SurW) + 78.65 (Oceano's remaining SurW Requested) = 405.65 AF.San Miguelito29.091279.26This Month%TotalJanuary to PresentUsageThis Month% of Annual RequestUsage% of Annual Request139.74Total Water Deliveries This Month48.0764102.499.239.26372.79Annual Request0.00Usage48.070.0078.650.00%0.00321.350.00405.650.002122.35303.00787.22892.0086.344190.91126.72136.00SWP DeliveriesSWP DeliveriesChange in Storage1459.97This Month Stored State Water97.3%6.1%92.7%0.0%100.0%8.0%96.0%0.0%100.0%2.9%35.2%2.1%8.7%7.6%21.9%0.0%0.0%4.7%93.2%2.3%8.8%7.3%22.9%0.0%15.0%0.0%19.4%0.0%0.0%100.0%0.0%100.0%0.0%92.7%100.0%98.4%100.0%35.2%92.5%17.0%EntitlementSurplusUsage%Usage%EntitlementSurplusUsage%Last Month Stored State WaterSurplus Requested0.00321.3520.00405.650.00747.00Friday, April 3, 2020Page 1 of 1Report printed by:AdminData entered by:D. Bravo$77$&+0(17DItem 8.i. - Page 5
5.44
0.54
0.00
4.70
2.14
0.24 0.00 0.00 0.00 0.00 0.000.52
1.42
5.16
0.22
0.94
0.00 0.00 0.00 0.00 0.00 0.00
2.87 3.10 2.77
0.90
0.33 0.32 0.62
1.34
2.03
3.02 3.25 2.91
1.13
0.41 0.07 0.03 0.02 0.32 0.62
1.70
2.24
3.12 2.98
0.00
2.00
4.00
6.00
8.00
10.00
12.00
14.00
0
5000
10000
15000
20000
25000
30000
35000
40000
1/1/20202/1/20203/1/20204/1/20205/1/20206/1/20207/1/20208/1/20209/1/202010/1/202011/1/202012/1/20201/1/20212/1/20213/1/20214/1/20215/1/20216/1/20217/1/20218/1/20219/1/202110/1/202111/1/202112/1/20211/1/20222/1/20223/1/2022Storage (AF)Date
LOPEZ RESERVOIR STORAGE PROJECTION
Actual Precipitation Predicted Precipitation Actual Storage
20,000 AF Storage Projection Storage Projection (No Rain)
1. Storage projection is based on predicted rainfall from longrangeweather.com, inflow based on predicted rainfall, 20-21 downstream release requests, and municipal usage.
2. Municipal Usage is based on Jan 2010-Dec 2020 average monthly deliveries.
3. Predicted inflow is based off of historical precipitation and storage data. Antecedant moisture conditions are factored into the model.The first rainstorms after months without
rain will cause less inflow than rainstorms during the rainy season. If the average daily rainfall for the previous three months is below 1 inch the model will multiply the predicted
inflow by 0.1, if the average is above 1 inch the inflow is multiplied by 1.25.
Attachment 2
Item 8.i. - Page 6
216.8
202
134
124
0
50
100
150
200
250
Sep-20 Sep-21
Monthly Water Use Comparison
Acre Feet Usage (gpcd)
Attachment 3
Item 8.i. - Page 7
ATTACHMENT 4
Below is the information you have submitted for the month of September 2021. If this
information is incorrect, you can edit the report or re-submit your report for the month
with the corrected information. We use your most recently submitted monthly report in
our calculations.
Reporter Shane Taylor
Urban Water Supplier (Number) Arroyo Grande City of (608)
Public Water System ID(s) CA4010001
Reporting Month 9/21
County / Counties San Luis Obispo
County Under Drought Declaration Yes
Water Shortage Contingency Plan 0
Water Shortage Level No
Population 17636
Total Potable Water Production 202 AF
Commercial Agricultural Water 0 AF
Residential Use Percentage 80%
CII Water 22.2 AF
Recycled Water 0 AF
Non-revenue Water AF
Estimated R-GPCD 99.53
Qualification
Emergency Response Section Revealed? Yes
State Water Resources Control Board Office of Research, Planning & Performance
Item 8.i. - Page 8