HomeMy WebLinkAbout12-15-2015 Item 14 - 2015 Water Resources Status Report
Meeting Date: 12/15/2015
FROM: Carrie Mattingly, Utilities Director
Prepared By: Aaron Floyd, Water Division Manager
Jennifer Metz, Utilities Projects Manger
Ron Munds, Utilities Services Manager
SUBJECT: 2015 WATER RESOURCES STATUS REPORT
RECOMMENDATION
Receive and file the 2015 Water Resources Status Report.
DISCUSSION
The 2015 Water Resources Status Report (Attachment A) provides an overview and update of the
City’s water resources. These reports have been provided to the City Council and community since
1985 and serve to both inform future policy decisions as well as provide historical documentation of
existing water conditions.
2015 Water Year Summary
Potable Water Use 4,988 acre feet
Recycled Water Use 168 acre feet
Per Capita Demand Per Day 97.3 gallons*
Per Capita Demand - 10 year running average 114.4 gallons
Water Projection Model as of November 30, 2015 3.5 years
Water Resource Availability (planning data)
Primary Water Supply
Reliability Reserve
Secondary Water Supply
10,005 acre feet
7,330 acre feet
1,174 acre feet
1,501 acre feet
* As a comparison, water demand in 2014 was 108.5 gallons per person per day. The reduction to 97.3
gallons per person per day amounts to a 10 percent decrease in one year.
Change in Reporting Period
Beginning this year, the reporting period has changed from the calendar year to the “water year”; a
timeframe from October 1 through September 30. This will cover the timeframe in which rainfall
typically occurs in our region and is consistent with other water reporting periods. The water year is
designated by the calendar year in which it ends. This report covers water year 2015.
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Response to Drought
Following the Governor’s Executive order in April 2015, the State Water Board adopted
mandatory reductions with the City’s required reduction at 12 percent. The community has done
a laudable job in meeting the mandated reductions and has continued to demonstrate its
commitment to resource conservation and stewardship.
As the drought continues into its fifth year, both the State and the City have taken increasing actions
to encourage water conservation through active outreach regarding the importance of water
conservation continue. Efforts made by the City in 2015 have included hosting a community
water forum, offering rebates and free water saving fixtures, and numerous site visits to assist
concerned residents. City staff aimed for a 17% reduction during warmer months in which
irrigation typically occurs to offset the lower reductions anticipated during winter months in
order to achieve the cumulative 12% reduction for the period from June 2015 to end of February
2016.
The following table is a summary of the water use reduction, compared to 2013, which
demonstrates the community’s success in reaching this goal.
Water Use Reduction from 2013
Month Percent Reduction
June 20
July 26
August 25
September 19
October 19
Cumulative 22.6
Recycled Water
Recycled water use for calendar year 2014 totaled 185 acre feet, up seven per cent from 177 acre
feet in 2013. The recycled water use for water year 2015 was 168 acre feet.
Corporation Yard Well
As part of the drought response strategy adopted by City Council in June, the use of the
Corporation Yard well located on Prado Road was brought under a permit system. Water use was
curtailed to only allow non-construction use within the San Luis Obispo groundwater basin. This
change has had the effect of generating 40 permit users for the Corporation Yard well as well as
increasing the number of recycled water permits for construction from 9 to 37 and a
corresponding increase in recycled water use for construction from 6 acre feet in 2014 to over 13
acre feet in 2015.
Water Modeling
The city uses two models to assist in water management. The first is the Water Projection Model
which is used to predict the City’s current water availability. This model was updated to include
data on rainfall, evaporation, stream inflow, future population growth, and downstream releases
from the 2012-14 time period to more accurately reflect the impacts of the drought on reservoir
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levels. Based on this analysis, the model indicated the City had approximately a three and a half
year supply of water as of November 2015.
The second model used is the Safe Annual Yield Model. This model defines the annual amount
of water available from Salinas and Whale Rock Reservoirs when operated in a coordinated
manner. Water from Nacimiento Reservoir is accounted for independently and not part of the
Safe Annual Yield Model since it is a contracted amount of water delivered on an annual basis.
The current combined Safe Annual Yield for Salinas and Whale Rock Reservoirs is 6,940 acre
feet per year. Since it is unknown how long the drought will last, model updates used
hypothetical precipitation scenarios for the upcoming rain season. The results of these model
runs showed that a relatively normal rainfall year would not impact the Safe Annual Yield;
however, a continued drought will negatively impact the Safe Annual Yield from these two
water sources.
Outlook for 2016
Work continues on several projects that will impact the City’s future water status. In September of
this year, City Council authorized the signing of the letter of intent to pursue an additional allocation
of over 2,100 acre feet of water from Nacimiento Reservoir. In early 2016, City Council will
consider taking further action related to Nacimiento water resources. The City’s Urban Water
Management Plan and Recycled Water Master Plan will be updated in 2016. Lastly, meteorologists
have predicted, and City staff have prepared for, a major El Nino event associated with an above-
normal rainfall season.
ENVIRONMENTAL REVIEW
This report does not meet the definition of a “project” under the California Environmental Quality
Act (CEQA).
FISCAL IMPACT
There are no fiscal impacts associated with the recommended action.
Attachments:
a a - 2015 Water Resources Status Report
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CITY OF SAN LUIS OBISPO
2015
Water Resources
Status Report
This Report Covers the Time Period of October 1, 2014 through September 30, 2015
Salinas Reservoir Dam, February 2015.
Photo credit: County of San Luis Obispo.
PREPARED BY:
Ron Munds, Utilities Services Manager
Jennifer Metz, Utilities Projects Manager
Aaron Floyd, Utilities Deputy Director-Water
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The Water Resources Status Report updates the City Council and community on existing water
resources. This report focuses on seven main areas:
I. Drought
II. Water Supply
III. Projected Water Supply
IV. Water Demand
V. Water Resource Availability
VI. Water Supply Accounting
VII. Water Demand Management
The 2015 Water Resources Status Report includes water production and water consumption
data for October 1, 2014 through September 30, 2015 and was prepared in accordance with the
City’s General Plan, Water and Wastewater Management Element (WWME), Policy A5.3.1.
Historically, data provided in the Water Resources Status Report reflected on the preceding
calendar year. Starting with this report, the Report corresponds to the Water Year (October 1
through September 30), the 12-month period for which precipitation totals are measured. This
change enables the City to better report on water supply availability issues.
I. DROUGHT
The statewide drought has continued and is now well into the fourth year. Governor Brown
declared a drought emergency on January 17, 2014 and, as part of the response, directed the
State Water Resources Control Board (State Water Board) to draft water conservation
regulations to respond to the emergency. The State Water Board adopted regulations
prohibiting water waste in July 2014, and issued directives to reduce water use statewide. In
response to the continuing drought conditions, the State Water Board extended the 2014
emergency regulations and added new measures on March 17, 2015. On April 1, 2015, the
Governor issued Executive Order B-29-15 mandating increased enforcement against water
waste and declared a statewide water use reduction goal of 25 percent. This action was
followed by the State Water Board adopting regulations that require specific water purveyors
to reduce water use in a range of 8 to 36 percent compared to their 2013 water usage . The
amount of the mandated reduction is dependent on the water purveyor’s per capita use in
2013. The City’s required reduction is 12 percent. The following is a summary of the City’s
progress of reaching this goal.
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2015 Reduction
from 2013
June 20%
July 26%
August 25%
September 19%
October 19%
The community has done an outstanding job in reducing water
consumption in response to the new regulations and the city is
on target to meet the State’s requirement.
LOCAL RESPONSE STRATEGY
The impacts of the 1987-1991 drought enculturated a strong
water conservation ethic in San Luis Obispo along with an
urgency to develop new water supply sources. The current
statewide drought brought about unprecedented regulatory action from the State of California
which resulted in a mandatory average 12 percent reduction in water use from June 2015 to
February 2016, when compared with 2013 water use numbers. To achieve this mandate, the
City Council adopted a drought response strategy in June 2015. This strategy includes:
1. Adoption of a resolution declaring a drought emergency;
2. Adoption of a resolution to defer new landscape installation or the use of modified
landscape plans during the drought emergency;
3. Introduction of an ordinance amending Chapter 13.07 of the City’s Municipal Code to
include two-day-a-week and time-of-day restrictions for outdoor watering;
4. Approval of an incentive program for high efficiency toilets and washing machines; and
5. Adoption of a resolution establishing a permit fee for the use of the Cor poration Yard
groundwater well.
This strategy relies on active enforcement of water waste prohibitions, with a core focus on
providing information and resources to the public
Nacimiento Reservoir Dam, February 2015.
Photo credit: County of San Luis Obispo.
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II. WATER SUPPLY
Per WWME Policy A2.2.1, 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 landscape irrigation and construction
water), with groundwater serving as a fifth supplemental source. The supply per source for
Water Year 2015 (October 1, 2014 to September 30, 2015) is summarized as follows:
2015 City Water Supply by Source (Acre Feet)
Salinas Whale Rock* Nacimiento Groundwater Recycled Total Water Demand
1,122 1,718 1,891 89 168 4,988
23% 34% 38% 2% 3% 100%
Notes:
All Values are rounded.
*Water delivered to Cal Poly State University is excluded from the City’s water demand.
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 related 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 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
Whale Rock Reservoir, February 2015.
Photo credit: County of San Luis Obispo.
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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 a
County Representative (who is a member of the County Board of Supervisors which also sits as
the Board of Directors for the Flood Control District), provides oversight to project operations,
maintenance, and the project budget. The Nacimiento pipeline was shut down on June 2, 2014
for emergency repairs and was offline for the remainder of 2014 , with flow being reinstated in
April of 2015.
RECYCLED WATER
Recycled water use for 2014 totaled 185 acre feet, up five
percent from 177 acre feet in 2013. For the 2015 Water
Year, the City delivered 168 acre feet of recycled water.
GROUNDWATER
The City stopped supplying groundwater to its drinking
water system in April 2015. Due to new regulatory
requirements, using the groundwater would require
additional costly treatment at the wells before the water
could be used. Groundwater wells remain in operable
stand-by condition should use of groundwater be
required in the future .
Pe r WWME Policy A 3.2.3, the Cit y does not consider
groundwater a source of supply due to limitation s on its
use. Cit y wells are summarized below:
Well Type Use Location
Pacific Beach #1 Potable Domestic Los Osos Valley Road near
Pacific Beach School
Corp Yard Well Non-potable Construction Water City Corporation Yard
Prado Road
Laguna Lake Golf Course Non-potable Irrigation Laguna Lake Golf Course on
LOVR
SLO City Farm Non-potable Irrigation SLO Community Farm off
Highway 101 & LOVR
Note: The City discontinued domestic groundwater use in 2015.
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43%
25%
21%
11%
Single Family
Residential Uses
Multi-Family
Residential Uses
Non-Residential Uses
Landscape Irrigation
III. PROJECTED WATER SUPPLY
The City uses a computer model to estimate its future reservoir storage in Salinas and Whale
Rock Reservoirs. This is accomplished by applying historical drought, weather patterns, water
use projections, reservoir data, and available water supplies from Nacimiento Reservoir, and
recycled water. The model assumes implementation of Stage I conservation measures when
supplies are projected to last three years. Stage II and III conservation measures are
implemented when water supplies are estimated to last two years and one year, respectively.
In December 2014 the model predicted water supplies would last six years. In early 2015, the
model was updated to include the new worst case drought information (climatic data for 2012,
2013, and 2014). The model indicates the City has approximately a three year supply of water
as of September 2015.
IV. WATER DEMAND
During Water Year 2015, 68 percent of water use in the City was for single and multi-family
residential uses. Historical water use is summarized below, as well as corresponding population,
per capita use rate, and precipitation. The 2015 per capita water use was 97.3 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 114.4 gpcd.
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Population, Water Use & Rainfall
Year Population Total Water Use
(acre feet)
Per Capita
(gpcd)
Rainfall1,2,3
(inches)
2006 44,559 5,999 120.2 17.2
2007 44,433 6,493 130.5 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
2014 45,473 5,524 108.5 14.2
2015 45,802 4,990 97.3 11.8
Ten-year per capita average: 114.4
Notes:
1. Rai nfa ll amou nts for 2005 –2012 cal endar year source: Cal Poly CIMIS W eather Statio n.
2. Rai nfa ll amou nt fo r calendar year 2013-2015: SLO Reservoir.
3. Rainfall for 2015 covers October 2014 through September 2015
V. WATER RESOURCE AVAILABILITY
The following table summarizes the Water Resource Availability to serve the community water
demand based on WWME Section 3. Water availability for 2015 is 10,005 acre feet.
2015 Water Resource Availability
Water Resource Acre Feet Description
Salinas & Whale Rock Reservoirs 6,940 Safe Annual Yield 1
Nacimiento Reservoir 3,380 Dependable Yield 2
Recycled Water 185 2014 Annual Usage 3
Siltation from 2010 to 2060 (500) WWME Policy A 4.2.2 4
10,005 2015 Annual Availability
NOTES:
1. 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 (calendar year 2014) 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.
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VI. 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 as
identified in the Land Use Element of the General Plan. Table
3 in the Land Use Element identifies an urban reserve capacity
of 57,200 people. 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 2, and the
population of 57,200 (2014 LUCE). Per WWME Policy A 5.2.2:
Primary Water Supply:
= Ten Year Average per Capita Water Use x City Build-out Population
= 114.4 gal/cap-day x 57,200 x 365 day/year x Acre-Ft/325,853 gal
= 7,330 Acre-Ft/year
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 20 percent of the ten-year average of per capita water use and the existing
City population (45,802, 2015 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 2014 City Population x 20%
= 114.4 gal/cap-day x 45,802 cap x 365 day/year x Acre-Ft/325,853 gal x 20%
= 1,174 Acre-Ft/year
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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
= 10,005 Acre-Ft/year A – 7,484 acre-Ft/year – 1,190 Acre-Ft/year
= 1,501 Acre-Ft/year
A 2015 Annual Availability
Water supply accounting is summarized as follows:
2015 Water Supply Accounting (acre feet)
Total Primary Water Supply Reliability Reserve Secondary Water Supply
10,005 7,330 1,174 1,501
VII. 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, the community has reduced its
annual average per capita water use from over 180 gallons in 1987 to 97 for the 2015 Water
Year.
REGIONAL COOPERATION
Beyond the involvement in the Nacimiento Water Project, 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 and the
regional water conservation group Partners in Water Conservation.
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Water Resources Status Report
Reporting Period
Water Year
Consistency
Drought Response
Month Percent
Reduction
June 20
July 26
August 25
September 19
October 19
Cumulative 22.6
17%
Reservoir Levels
•Rainfall
Naci Pipeline
Recycled Water
108 gpcd 97 gpcd =
2015
Fiscal Impacts
Revenue
33% of Year / 38% Budget Collected
Drought Surcharge
Drought Response Budget
Temporary Employee
54 Rebates
Over 2,000 Water Saving Devices
Non Potable Water Use
Corporation Yard Well
Total Permits 40
Inside City 23
Outside City 17
Recycled Water - Construction
2014 2015
9 Permits 37 Permits
6 Acre Feet 17 Acre Feet
Recycled Water
Year 2013 2014 2015
Acre Feet 177 185 188
Water Quality
Groundwater
<2%
Ceased in April
Availability
Disinfection By-Products
August & November Below Limits
Actions
El Niño
Local DCPP
3.64” This Season
3.60” Average Season
2016
Nacimiento Full Allocation
Urban Water Management Plan
Water Shortage Contingency Plan
Water Supply Reliability
Recycled Water Master Plan
Conjunction with WRRF
Expansion of System
Storage
Questions
Recommendation
Receive and file the 2015
Water Resources Status Report