Conservation Potential and California’s Urban Water Demand Gary Wolff, P.E., Ph.D. Principal Economist & Engineer April 2, 2004 Presentation at the 4 th Annual North Bay Water Conference

Can We Grow The CA Economy Without More Water?  Yes.  We’ve Done This For the Last 30 Years  Can Continue If More Efficiency Is Possible  Our Efficiency Potential Is STILL Large  Our Efficiency Potential is Cost-Effective  The Limiting Resource Is NOT WATER: It is Our Ability to See the Big Picture and to Overcome Implementation Obstacles

Gleick 2001 The link between water use and economic growth can be broken

California Water Withdrawals and Economic Output Trends

But Can We Continue To Grow Without Additional Physical Water?  No Comprehensive Statewide Estimate of the Potential for Urban Water Conservation Had Ever Been Done.  Such An Analysis – Done Right – Must Use An “End-Use” Approach.  Important Data Gaps Remain to be Filled

The Pacific Institute Report -- “Waste Not, Want Not: …”  Three-Year Process  Extensive Independent Reviews  Report Released in November 2003  Report and Appendices Available Online:  Funded by DWR/CalFed; and the Hewlett, Environment Now, & MacArthur Foundations

California Urban Water Use – 2000 (6.9 million acre-feet per year)

CII Sectors by Group COMMERCIAL/ INSTITUTIONAL Educational (K-12, Colleges, Special Education) Hotels Restaurants Food and Beverage Stores Other Retail Stores Office Buildings Hospitals Golf Courses Coin Laundries Industrial Laundries INDUSTRIAL Food Processing Dairy Meat Processing Fruit and Vegetable Proc. Beverages Petroleum Refining High Technology Paper - Paperboard Mills Textiles Fabricated Metals

How We Evaluated CII Potential

Indoor Residential Water Use – 2000 (2.3 MAF/yr) End UseAcre-feet per year Toilets734,000 Showers496,000 Faucets423,000 Clothes Washers330,000 Leaks285,000 Dishwashers28,000 Total2,296,000

End-Use Analysis: Clothes Washers  WU(t) = HH(t) x L/D x G/L = WU(t) –WU (t) = Total Water Use at Time “t” –HH (t) = Households at Time “t” –L/D = Loads per HH per Day –G/L = Gallons per Load  Compare WU(t) When G/L Changes, Holding Size of Loads Constant  Estimate of Conservation Potential Based on Comparing Average G/L Now With Average G/L of “Efficient” Machines

Some Economic Results – Residential Indoor Conservation

Haasz et al Indoor Residential Conservation Potential Over Time No Efficiency Improvements Current Use Cost-Effective Efficiency *

Total Urban CA Efficiency Potential SectorUrban Water Use, 2000 (TAF/Yr) Efficiency Potential Cost- Effective Potential Res-Indoor2, Res-Outdoor983 – 1, to Comm/Inst.1, Industrial665260Incl. in C/I Unaccounted695Not Eval. Total6,960 (+/- 10%)2,3372,020

Conclusions:  Growth in Water Demand Is Not Inevitable  Future Demand Need Not Grow Because Additional Improvements in Water Use Efficiency Are Possible and Economical  But Implementing Change Requires: –Partnerships Across Traditional Boundaries (e.g., Water/ Wastewater/ Stormwater/ Energy) –Capturing the “Other Benefits” We Identified –Better Balance of New (e.g. Customer Behavior) and Old (e.g., Hydrologic) Uncertainties