Presentation on Local Supply Development in San Diego County by Toby Roy, Water Resources Manager for the San Diego County Water Authority. Provided at Water Talks: New Challenges, New Supplies on September 13, 2011. Presentation covers recycled water, conservation, stormwater catchment, graywater.

1. Local Water Supply Development
Toby Roy, Water Resources Manager
September 13, 2011
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2.  Local Water Supply Development
o Supplies developed by water agencies
 Customer demand reduction
o Conservation
o Graywater
o Stormwater

3. San Diego County Water Supply Diversification
1991 2011 2020
Population 2.49 mil Population 3.16 mil Population 3.44 mil
5% 6% 7%
5% 3% 8% 4%
13%
12% 6%
552,000
10%
13% 285,000 231,000
95%
Total = 578,000 AF
30%
47%
12%
Total = 611,000 AF 24%
Total = 779,000 AF
(includes conservation savings)
(includes conservation savings)
Conservation & Recycling:
1991=<1% Metropolitan Water District
2011=42%
Local Surface Water
2020=53%
Imperial Irrigation District Transfer Groundwater
All American & Coachella Canal Lining Seawater Desalination
Local Conservation
Recycled Water
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4.  Comparison to imported water costs
 Advancement in technology
 Drought proof supplies
 Reduced dependence on Delta
 Local control
 Multiple benefits
 Regulatory Feasibility

5.  Local supplies will provide 23%
of the region’s water supply by
2020
 Groundwater
 Recycled Water
 Seawater desalination
◦ Carlsbad
◦ Camp Pendleton
◦ Rosarito Beach
 Indirect Potable Reuse
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6. 28,000 af/year today, growing to
44,000 af/year by 2020
o Drought-proof water supply
o 17 agencies in San Diego purvey
recycled water
o Primarily used for landscape
irrigation

7. Industrial and Commercial Uses
Dust Control
Cooling Towers
Decorative Water Features
Johnson & Johnson
Toilet/Urinal Flushing
Landscape Irrigation
B D Biosciences Pharmagen

8.  Non-Potable Reuse
◦ Tertiary treatment:
Coagulated, filtered,
disinfected
◦ Ensure no cross-connections
between potable and
recycled water
 Potable Reuse
◦ Advanced treatment
◦ Environmental barrier

9.  Continue existing non-potable uses
 Strong interest in expanding potable reuse
◦ Large scale non-potable opportunities are limited
◦ Reliable, proven, cost-effective technology is
available
◦ Regulatory reform (SB 918)

10.  20,000 af/year today, growing to 27,000 af/year by 2020
 San Diego does not have significant underground storage basins
 Brackish groundwater must be desalinated
 Seven local agencies have groundwater projects

11. Cost of the Next Increment of Local Supply
Actual Proposed San Diego Region Project Unit Costs - $/AF
(Before incentives, grants, or netting out avoided costs)
Carlsbad (Poseidon)
~ $1,800
(2011$)
Mission Basin Narrows
$1,700
Otay River
$2,100
North City IPR *
$2,190
(2005$)
0 500 1,000 1,500 2,000 2,500
$/AF
Brackish Groundwater
Indirect Potable Reuse
* Cost of re-treatment not
Seawater Desalination included
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12.  Agencies are accountable under SBX 7 7
 Retail agencies establish targets (GPCD)
◦ Regional Average: 167 GPCD including Agriculture
 Develop measures, programs and policies
 Targets have been included in UWMP
 13% of water supply (104,000 AF) in 2020

13. Regional Actual & Target GPCD1
240
220
Baseline GPCD - 209
200
Actual GPCD
180
GPCD
2020 Target GPCD – 167 2
160
Current GPCD - 141
140
120
100
1995 2000 2005 2010 2015 2020
Fiscal Year
1Municipal,industrial and agricultural use; excludes recycled water use
2Target based upon 2009 California law SBX7-7

14. Maintaining Water Use Efficiency
 Maintain recent gains in
conservation
◦ Regional water use down about
30% since 2007
 Efficiency needs to be social
norm
 Collaborative Approaches
◦ Stormwater and conservation
 Emphasis on outdoor
efficiency
◦ Market transformation
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15.  SB 1258 (2008)
◦ Approved by Building Standards
Commission
◦ Local Adoption may be more
stringent
 SB 518 (2010)
◦ BSC to develop standards for
non- residential use
 SB 849 (2011)
◦ Pending governor’s signature
◦ Makes indoor use possible
◦ Limits local discretion to be
more stringent

16.  No Permit, No Notice:
◦ Flow to irrigation
◦ No connection to potable
◦ No pump
◦ Contained on site
◦ No ponding/runoff
◦ Minimize contact
◦ No hazardous constituents
◦ Operations manual

17.  No permits required for outdoor landscape use
 Homeowner harvesting not a significant supply for
San Diego
◦ Rainwater events do not coincide with demand
2.5
8
7
2 6
5
1.5 4
3
1 2
1
0.5 0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
0
July
Feb
Aug
June
Nov
April
Jan
Mar
Dec
May
Sept
Oct

19.  Licensed contractors may install
rainwater capture systems for
landscaping
 Allows indoor use of stormwater:
◦ Filtered and disinfected
◦ Local agency issues permit after
consulting with local health
department
◦ Plumbing installed per IAPMO Codes

20.  Visit our website: sdcwa.org
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