Post on 18-Sep-2020
Santa Margarita Groundwater AgencyOctober 25, 2018
City of Santa Cruz Water System and Supply Augmentation Strategy
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3
Santa Cruz’s San Lorenzo River Water Rights
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Santa Cruz’s Sources of Supply
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Beltz Wells
4%
Tait Wells
3%Loch
Lomond
22%
San Lorenzo
River
46%
North Coast
Streams
25%North Coast Streams
(1890)
Loch Lomond Reservoir
(1960)
San Lorenzo River
(1924)Beltz Wells
(1964)
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The 20 year water demand forecast, including projected growth and consistency
with the City’s General Plan, is FLAT
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Service Area Population and Population Forecast*
20101 2020 2025 2030 2035
Inside City2 59,946 66,860 70,058 73,375 76,692
Outside City3 31,342 32,543 33,562 34,614 35,698
Service Area Total
91,288 99,403 103,620 107,989 112,390
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* – As used in City of Santa Cruz 2015 Urban Water Management Plan 1 – Actual population per 2010 Census2 – AMBAG 2014 Regional Growth Forecast (adopted June 11, 2014), includes UCSC population3 – Developed by Water Department Staff from 2014 Regional Growth Forecast data
Santa Cruz’s Supply
is Highly Variable
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0
50
100
150
200
250
300
350
400
Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Oct
Loch Lomond
Tait Street
North Coast
Beltz Wells
TOTAL DEMAND
Mill
ion
of
Gal
lon
s
The projected worst year gap is BIG – peak season shortage with DFW-5 flows is 1.2 bg
billion gallons
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Fish Flow Commitments
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Putting the City’s Summer Fish Flow Commitments in Context
June Fish Flow Releases
0
2
4
6
8
10
12
Year Type
Mill
ion
s o
f G
allo
ns
pe
r D
ay
Driest Dry Normal Wet Wettest
June Water System Production
0
2
4
6
8
10
12
June Production
Mill
ion
s o
f G
allo
ns
Pe
r D
ay
2012 (Normal) 2013 (Dry) 2014 (Dryest)
2015 (Dry) 2016 (Normal) 2017 (Wettest)
2018 (Dry) 13
Water Supply Advisory CommitteeApril 2014 – October 2015
• 14 citizens appointed by the City Council
• Interests represented included: inside and outside city water customers, the Chamber, Coastal Watershed Council, Desal Alts, Sierra Club, Surfrider, Sustainable Water Coalition, the Water Commission and 3 community-at-large members.
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WSAC’s Problem StatementJuly 2015
• Limited Storage
• Need to meet fish flow requirements and prepare for potential climate change impacts
• Resulting peak-season gap: ≈1.2 billion gallons worst year shortage
• Water conservation alone is not enough
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Our Water, Our Future: the October 2014 “Santa Cruz Water Supply Convention,” showcased more than 40
water supply solutions and attracted 350 people
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Nearly 100 Alternative Water Supply Solutions Identified and Screened
• Expanded conservation, e.g.,
– Peak season demand reduction
– Water neutral development
• Decentralized systems, e.g.,
– Graywater
– Rainwater catchments
– Water from humidity in the air
• Winter flow harvest, e.g.,
– Passive and active recharge
– Water transfers and exchanges
• Water reuse
– Various approaches to non-potable and potable reuse
• Desalination
– Various locations and technological approaches to seawater desalination
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WSAC Supply Augmentation Recommendations
1. Implement additional water conservation efforts
2. Explore the feasibility of winter water harvest to create drought supply of 3 billion gallons to provide for 2 years of back to back drought
A. In-lieu water transfers/exchange with Soquel Creek Scotts Valley and/or San Lorenzo Valley water districts
B. Aquifer storage and recovery (ASR) in the Santa Margarita and/or Santa Cruz Mid-County Basins
3. Explore the feasibility of alternative water supplies to supplement existing sources during droughts
A. Recycled water
B. Desalination
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Strategy 1Element 1 –
In Lieu
Strategy 1 Element 2 –
ASR
Strategy 1Combined In Lieu and ASR
Strategy 2Element 3 –
Purified Recycled
Water
Strategy 2 Element 3 –Desalination
Thre
sho
ld M
etri
cs
(qu
anti
tati
ve
ind
icat
ors
)
TechnicalFeasibility
Y/N Y/N Y/N Y/N Y/N
Cost (ACAYY) Annual $/mg of yield
Annual $/mg of yield
Annual $/mg of yield
Annual $/mg of yield
Annual $/mg of yield
Yield Billion gallons Billion gallons Billion gallons Billion gallons Billion gallons
Timeliness Meets/Does Not Meet
Meets/Does Not Meet
Meets/Does Not Meet
Meets/Does Not Meet
Meets/Does Not Meet
Gu
idin
gP
rin
cip
les
(qu
alit
ativ
e, c
on
sum
er
rep
ort
typ
e in
dic
ato
rs) Public Health
Public Acceptance
Regional Collaboration
Plan Goal
Incremental Implementation
Ad
dit
ion
al
Val
ue
s SystemRobustness
System Resilience
System Redundancy
Adaptive Flexibility
QUESTIONS?