HomeMy WebLinkAbout11-18-2014 C8 Revised Water Resources Status ReportCity of San Luis Obispo, Council Agenda Report, Meeting Date, Item Number
FROM: Carrie Mattingly, Utilities Director
Prepared By: Wade Horton, Water Division Manager
SUBJECT: REVISED 2014 WATER RESOURCES STATUS REPORT
RECOMMENDATION
Receive and file the Revised 2014 Water Resources Status Report.
DISCUSSION
This report replaces the 2014 Water Resources Status Report received by Council on September
2, 2014. Incorrect data related to the per capita demand calculations and 2014 Water Supply
Accounting is corrected in this Revised Report.
Annual reports relative to the City’s water resources have been provided to the City Council since
1985. The original report accepted by Council misapplied how Cal Poly agricultural water was
accounted for in the City per capita demand calculations – the error was discovered in
association with the City’s August 2014 water production reporting to the State for mandatory
emergency drought regulations.
Revised 2014 Water Resources Status Report Summary
Calendar year 2013 was the City’s driest year on record. In January 2014, the Governor declared a
statewide drought emergency. Although San Luis Obispo County is now facing D4 Exceptional
Drought conditions as characterized by the National Oceanic and Atmospheric Administration
(NOAA), prudent planning and investment in a multi-source water supply (Salinas and Whale Rock
Reservoirs, Nacimiento Pipeline Project, groundwater, and recycled water) provided sufficient
water to meet 2013 customer demand. Based on the prior worst case drought scenario the City’s
water model, as of July 2014, shows approximately 7 years of City water supply remaining, the
last three of which would require mandatory rationing.
Water Supply
As of July 2014, the City’s two water supply reservoirs (Salinas and Whale Rock) were at 30
percent and 50 percent storage capacity respectively. In addition, the City has contractual rights
for 3,380 acre feet per year from the Nacimiento Reservoir.
Recycled water use for calendar year 2013 totaled 177 acre feet, up seven percent from 165 acre
feet in 2012. During 2013, two new sites were connected to the City’s recycled water distribution
system to provide landscape irrigation.
Water Demand
The City’s total calendar year 2013 water use was 5,892 acre-feet, with a per capita demand of
116 gallons per day (gpcd). The per capita use rate is not the amount that the average person uses
but takes into account all water uses including residential, commercial, industrial, and landscape.
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Revised 2014 Water Resources Status Report Page 2
In 2013 the water use rate increased from 109 (in 2012) to 116 gpcd. This increase is no doubt
influenced by the drought and related increase in landscape irrigation. Positive changes in the
economic climate resulting in significant increases in tourism and construction also impact the
per capita numbers.
Table 1: Population, Water Use & Rainfall*
Year Population Total Water
Use (acre feet)
Per Capita
(gpcd)
Rainfall
(inches)
2004 44,298 6,239 125.7 21.0
2005 44,687 6,098 121.8 20.8
2006 44,559 6,000 120.2 17.2
2007 44,433 6,494 130.5 12.7
2008 44,579 6,359 127.3 18.1
2009 44,829 6,134 122.2 18.9
2010 44,948 5,489 109.0 36.0
2011 45,418 5,285 103.9 18.9
2012 45,308 5,541 109.2 21.5
2013 45,541 5,892 115.5 3.8
Ten-year per capita average 118.5
* Table corrected
Water Resource Availability
Based on the policies adopted in the City’s Water and Wastewater Management Element
(WWME), Table 2 summarizes the available water supplies to serve the community’s water
demand.
Table 2: 2014 Water Resource Availability
Water Resource Acre Feet Description
Salinas & Whale Rock Reservoirs 6,940 Safe Annual Yield
Nacimiento Reservoir 3,380 Dependable Yield
Recycled Water 177 2013 Annual Usage
Siltation from 2010 to 2060 (500) WWME Policy A 4.2.2
9,997 2014 Annual Availability
Water Supply Accounting
WWME policy specifies that the City will account for water supplies necessary to meet three
specific community needs: 1) Primary Water Supply, 2) Reliability Reserve, and 3) Secondary
Water Supply, which are discussed in detail in the 2014 Water Resources Status Report
(attached) and summarized in Table 3 below.
Table 3: 2014 Water Supply Accounting*
Total Primary Water Supply Reliability Reserve Secondary Water Supply
9,997 7,128 1,209 1,660
* Table Corrected
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Revised 2014 Water Resources Status Report Page 3
Water Demand Management
The City’s water conservation program continues to implement the California Urban Water
Conservation Council’s Best Management Practices as defined in its Memorandum of
Understanding Regarding Urban Water Conservation in California. The water conservation
program will continue to play an important role in the future as the City faces new water supply
challenges attributable to climate change and regulatory requirements related to statewide water
use reduction goals.
2014 State Emergency Drought Regulations
On July 15, 2014, the California State Water Resources Control Board (Water Board) adopted
emergency drought regulations that must be implemented by all urban water suppliers who have
over 3,000 water connections regardless of that community’s water supply situation. The
emergency regulations specifically mandate the City implement mandatory outdoor water
restrictions and water waste prohibitions or face fines up to $10,000 a day and no access to state
grants and loans.
On August 19, 2014 the City Council supported changes to the Municipal Code allowing for the
restriction of outdoor irrigation of ornamental landscape and turf with potable water to three days
a week, and allocated funds to support an education and public outreach program. On September
16, 2014, the City Council adopted a Resolution to implement the three day a week watering
restrictions as mandated by the State.
FISCAL IMPACT
No fiscal impact is associated with the recommended action.
ATTACHMENT
Attachment 1 – Revised 2014 water Resources Status Report
T:\Council Agenda Reports\2014\2014-11-18\Revised Water Resources Status Report (Mattingly-Horton)
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PREPARED BY:
Ron Munds, Utilities Services Manager
Jennifer Metz, Utilities Project Manager
Wade Horton, Deputy Director-Water
City of San Luis Obispo
WATER RESOURCES STATUS REPORT
2014
REVISION 1: 14 OCTOBER 2014
This revision corrects per capita demand calculations and 2014 water supply
accounting. The original report accepted by City Council on 02 September 2014
misapplied how Cal Poly agricultural water was accounted for in the city per
capita demand calculations—this revision corrects that error.
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Table of Contents
CITY OF SAN LUIS OBISPO
2014 Water Resources Status Report
WATER SUPPLY
Salinas and Whale Rock Reservoirs 3
Nacimiento Water Project 4
Recycled Water 4
Groundwater 4
Projected Water Supply 4
WATER DEMAND 5
WATER RESOURCE AVAILABILITY
Water Supply Accounting 6
WATER DEMAND MANAGEMENT
2014 State Emergency Drought Regulations 7
REGIONAL COOPERATION 8
LIST OF TABLES
2013 City Water Supply by Source 3
Current Supply Status 3
City Wells 4
Population, Water Use & Rainfall 5
2014 Water Resource Availability 6
2014 Water Supply Accounting 7
LIST OF FIGURES
Reservoir Storage Curve 5
2013 Water Use by Category 5
Water Conservation Legislation Summary 8
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City of San Luis Obispo
2014 Water Resources Status Report
Although the Governor declared a statewide drought emergency in January 2014 and San Luis Obispo
County is currently experiencing a category D4 Exceptional Drought, our city’s local water supply
remains reliable and secure. Assuming historical worst-case drought conditions and current reservoir
storage levels, mid July 2014 water projection modeling estimates about seven years of water currently
available (with the last three of those years being a period where mandatory conservation actions
would occur). Investment in a multi-source water supply allows for responsible use even following
2013’s driest year on record.
This 2014 Water Resources Status Report is prepared in accordance with the Water and Wastewater
Management Element of the General Plan (WWME) Policy A 5.3.1. This report covers production and
use information for calendar year 2013.
WATER SUPPLY
Per WWME Policy A 2.2.1, the city uses multiple water sources to meet its water supply needs. The city
has four primary water supply sources including Whale Rock Reservoir, Salinas Reservoir, Nacimiento
Reservoir, and recycled water (for irrigation), with groundwater serving as a fifth supplemental source.
Calendar year 2013 water supply per source is summarized as follows:
2013 City Water Supply by Source (Acre Feet)*
SalinasWhale Rock**NacimientoGroundwaterRecycled Total Water Demand
1,4942,897 1,247 77 177 5,892
25%49%21%1%3%100%
*Values rounded
**Does not include Cal Poly Domestic or Agriculture
SALINAS & WHALE ROCK RESERVOIRS
Salinas and Whale Rock Reservoirs have served as the city’s primary water supplies for over 50 years.
The city pays the County of San Luis Obispo Flood Control and Water Conservation District (County)
to provide oversight, operations, and maintenance of the Salinas Dam and water delivery facilities.
The City of San Luis Obispo provides the oversight, operations, and maintenance of the Whale Rock
Reservoir for the benefit of the Whale Rock Commission, a joint powers agency made up of Cal Poly
State University, California Men’s Colony, and the City. The city draws water from these two reservoirs
Current Supply Status
(As of July 1, 2014)
Available Storage
(Acre Feet)
Salinas Reservoir 7,229
Whale Rock Reservoir (City Allocation)9,015
Total Storage 16,244
% of Maximum Storage 36%
32014 Water Resources Status Report
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to maximize the long-term water supply available from these two sources. In addition, the City has in
a coordinated manner adopted policies in the WWME to account for reductions in storage capacity at
each lake resulting from siltation.
NACIMIENTO WATER PROJECT
Water deliveries from the Nacimiento Reservoir began on January 5, 2011. The City has a contractual
right to 3,380 acre feet per year. The county operates and maintains the project that delivers water from
Nacimiento Reservoir to participating agencies (currently the cities of Paso Robles and San Luis Obispo,
Atascadero Mutual Water Company, Templeton Community Services District, and County Service Area
10A [Cayucos]). The Nacimiento Project Commission, which is made up of representatives from each
of the four agencies’ governing boards and County Representative (i.e. County Board of Supervisors),
provides oversight to project operations, maintenance, and the project budget.
RECYCLED WATER
Recycled water use for calendar year 2013 totaled 177 acre feet, up seven percent from 165 acre feet
in 2012. During 2013, two new sites (America’s Tire and Mangano Homes streetscape) were connected
to the city’s recycled water distribution system to provide landscape irrigation.
GROUNDWATER
Per WWME Policy A 3.2.3, the city will continue to use groundwater for domestic purposes when
available, but will not consider this source of supply as a part of its water resources availability due to
limitations for the use of groundwater resources. City wells are summarized below:
City Wells
Well Type Use Location
Pacific Beach #1 Potable Domestic Los Osos Valley Rd. near
Pacific Beach School
Corp Yard Well*Non PotableConstruction Water City Corporation Yard
Prado Rd.
Laguna Lake Golf Course #1 Non PotableIrrigationLaguna Lake Golf Course
SLO Farm**Non PotableIrrigation SLO Community Farm off
HWY 101 & LOVR
*Use of the City Corporation Yard well has increased from prior years.
The Utilities Department is currently evaluating the use of this well.
**Installed May 2014 for agricultural irrigation.
PROJECTED WATER SUPPLY
The City uses a computer model to estimate the city’s future reservoir storage in Salinas and Whale
Rock Reservoirs, applying historical drought weather patterns, water use projections, reservoir data, and
available water supplies from Nacimiento Reservoir, recycled water, and limited groundwater. The model
assumes implementation of Stage I conservation when supplies are projected to last only three years.
Stage II and III conservation measures are implemented when water supplies are estimated to last only
two years and one year, respectively. Assuming an extended drought, the model predicts current water
supplies will last seven years. See the following reservoir storage curve figure for details.
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WATER DEMAND
Water use by category for 2013 is shown here. Historical
water use is summarized below, as well as corresponding
population, per capita use rate, and precipitation. The 2013 per
capita water use was 116 gallons per capita per day (gpcd).
Based on WWME policies, the City uses the ten-year
gpcd average to project water required to serve build-out
population. The ten-year average water use is 119 gpcd.
Population, Water Use & Rainfall
Year Population Total Water Use
(acre feet)Per Capita 1 (gpcd)Rainfall (inches)
200444,298 6,239 125.7 21.0
200544,687 6,098 121.8 20.8
200644,559 6,000 120.2 17.2
200744,433 6,494 130.5 12.7
200844,579 6,359 127.3 18.1
200944,829 6,134 122.2 18.9
201044,948 5,489 109.0 36.0
201145,418 5,285 103.9 18.9
201245,308 5,541 109.2 21.5
201345,541 5,892 115.5 3.8
Ten-year per capita average 118.5
NOTE:
1. Rainfall amounts for 2004–2012 calendar year source: Cal Poly CIMIS Weather Station.
Rainfall amount for calendar year 2013: SLO Reservoir.
2013 Water Use by Category
Reservoir Storage Curve
Single Family Residential 41%
Multi Family Residential
20%
Commercial
Institutional 29%
Landscape Irrigation
11%
52014 Water Resources Status Report
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WATER RESOURCE AVAILABILITY
The following table summarizes the Water Resource Availability (based on WWME Section 3), to serve
community water demand. Water availability for 2014 is 9,997 Acre-Feet.
2014 Water Resource Availability
Water Resource Acre Feet Description
Salinas & Whale Rock Reservoirs 6,940 Safe Annual Yield1
Nacimiento Reservoir 3,380 Dependable Yield2
Recycled Water 177 2013 Annual Usage3
Siltation from 2010 to 2060 (500)WWME Policy A 4.2.24
9,997 2014 Annual Availability
NOTES:
1. Quantity of water which can be withdrawn every year while operating both reservoirs in coordinated operations under
critical drought conditions. Safe Annual Yield determined from computer model, which accounts for siltation loss through 2010
(per WWME Policy A 4.2.1).
2. Dependable Yield is the contractual amount of water the City has rights to from Nacimiento Reservoir.
3. The quantity of recycled water included is the actual prior year’s recycled water usage (2013) per WWME Policy A 7.2.2.
4. Reservoir siltation is a natural occurrence that reduces storage capacity over long periods, resulting in the reduction of safe
annual yield.
WATER SUPPLY ACCOUNTING
Per WWME Section 5, the City will account for water supplies necessary to meet three specific
community needs:
1. Primary water supply 2. Reliability reserve 3. Secondary water supply
The primary water supply is defined as the amount of water needed to serve the build-out population
of the city (Table 4, 2013 Water and Wastewater Development Impact Fee Study). The quantity of water
needed for the primary water supply is calculated using the ten-year average of actual per capita water
use, shown in Table 4, and the city’s build-out population 53,700. Per WWME Policy A 5.2.2:
Primary Water Supply:
= Ten Year Average per Capita Water Use x City Build-out Population
= 118.5 gal/cap-day x 53,700 cap x 365 day/year x Acre-Ft/325,853 gal
= 7128 Acre-Ft/year
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The reliability reserve provides a buffer for future unforeseen or unpredictable long-term impacts to the
city’s available water supply. The quantity of water for the reliability reserve is established using twenty
percent of the ten-year average of actual per capita water use and the existing city population (45,541,
2013 population). The reliability reserve concept is included in the city’s charter (Section 909) which
identifies that the water may not be used to serve future development, and is defined per WWME
Policy A 5.2.3:
Reliability Reserve:
= Ten Year Average per Capita Water Use x 2013 City Population x 20%
= 118.5 gal/cap-day x 45,541 cap x 365 day/year x Acre-Ft/325,853 gal x 20%
= 1,209 Acre-Ft/year
The secondary water supply is the amount of water remaining from the city’s available water resources
above those needed to meet the primary water supply and reliability reserve. The secondary supply
is identified to meet peak water demand periods or short-term loss of city water supply sources, per
WWME Policy A 5.2.4:
Secondary Water Supply:
= Current Annual Availability – Primary Water Supply – Reliability Reserve
= 9,997 Acre-Ft/year A – 7,128 Acre-Ft/year – 1,209 Acre-Ft/year
= 1,660 Acre-Ft/year
Water supply accounting is summarized as follows:
2014 Water Supply Accounting (Acre Feet)
TotalPrimary Water SupplyReliability ReserveSecondary Water Supply
9,997 7,128 1,209 1,660
WATER DEMAND MANAGEMENT
The City’s water conservation program is an integral part of its overall water management strategy. In
the late 1980’s, the City implemented effective water efficiency programs and policies that allowed for
continued community growth and economic development during water-constrained periods. Through
strong conservation efforts, our community has reduced its annual average per capita water use from
over 180 gallons in 1987 to 116 gallons in 2013.
During 2013, 1750 requests were received for assistance with high water bills, leak detection
assistance, and general consultations regarding billing problems. In addition, approximately 355 utility
billing adjustment requests were processed during 2013.
Legislation passed over the years requires water agencies to implement water conservation measures
in order to be eligible for state grants, loans, or assistance, and is summarized in Figure 3.
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Figure 3: Water Conservation Legislation Summary
2014 STATE EMERGENCY DROUGHT REGULATIONS
On July 15, 2014, the California State Water Resources Control Board (Water Board) adopted
emergency drought regulations that must be implemented by all urban water suppliers who have over
3,000 water connections regardless of that community’s water supply situation. Water purveyors who
do not implement the mandatory requirements face up to $10,000 per day in fines and other penalties.
The Emergency Regulations are in effect for 270 days but can be rescinded, extended or amended
based on drought conditions.
Notwithstanding the city’s stable water supply position, the Emergency Regulations specifically
mandate that the City implement mandatory outdoor water restrictions and water waste prohibitions
or face fines up to $10,000 a day and no access to state grants and loans. Accordingly, city council
adopted an ordinance limiting the outdoor irrigation of ornamental landscape and turf with potable
water to three days a week, and allocated funding for education and public outreach efforts.
REGIONAL COOPERATION
The City is a participating member of the Water Resources Advisory Council and Regional Water
Management Group, which promotes collaborative, integrated management of water resources within
San Luis Obispo County and provides policy recommendations to the County Board of Supervisors.
In addition, the City participates in the Paso Robles Groundwater Basin Advisory Committee.
URBAN WATER
MANAGEMENT PLANNING ACT
Passed in 1984, requires agencies to report
progress in implementing Water Demand
Management Measures law. The City’s 2010
Urban Water Management Plan outlines
the City’s water conservation program and
verification of compliance with the act.
SBx7-7
Enacted in November 2009, requires increase in
water use efficiency and sets goal of reducing
per capita urban water use by 10% in 2015 and
20% in 2020. City target is 120 gpcd in 2015
and 117 gpcd in 2020 – city use was 116 gpcd in
2013, exceeding targets.
AB 1420
Enacted in January 2009, specifies eligibility
for water management grants or loans be
conditioned on implementation of water Demand
Management Measures described in Water Code
Section 10631(f).
CLEAN WATER STATE REVOLVING FUND
REQUIREMENTS
In order to qualify for a State Water Resources
Control Board loan, an agency must comply
with either the Demand Management Measures
in the Urban Water Conservation Planning Act
or the California Urban Water
Conservation Council Best
Management Practices.CITY COMPLIANT
YES
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