Urban Water Demand Trends Conservation and the Future of Residential Water Use Peter Mayer, P.E.
Water Demand Management: Why? Water shortages Expensive to develop new supplies Climate change
Demand Management = Serious Business
vs Notorious Recent Historical Droughts PDSI = Palmer Drought Severity Index PDSI was developed by Wayne Palmer in the 1960s and uses temperature and rainfall information in a formula to determine dryness. Source: Dr. Martin Hoerling, NOAA Earth System Research Laboratory
Utilities are Asking: Where did the demand go? City of Westminster, CO average annual household water use, 2000 – 2010, with trend line
Seattle Public Utilities
Forecast Without Conservation
Firm Yield in 2013
Forecast With Conservation
2013
A brief history of demand forecasting in Seattle
Seattle Saved $725 million PV Cost of New Supply $800 Million PV Cost of Conservation: $ 75 Million _______________________________________________________________ NPV : $725 Million
Avg. Annual Use Per SF Home (kgal) Source: Mayer, P. et. al Residential End Uses of Water Update. AWWA - ACE, Denver, CO.
1999 REUWS vs REUWS gallons per household per day
2014 REUWS Update
Homes Meeting Efficiency Criteria Toilet < 2 gal., Clothes washer <30 gal.
Technological change Behavioral change More intense and frequent drought Water demand management at the retail level
Peter Mayer, P.E.