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Water Supply Update

Voluntary Water Conservation - Goal is 10% Reduction

On January 31, 2014, the San Francisco Public Utilities Commission (SFPUC) officially asked all customers of the Hetch Hetchy Regional Water System to voluntarily curtail water consumption. The goal is to reduce system-wide usage by 10%. The request applies to all residential, commercial, industrial, municipal and wholesale customers that receive water from the Hetch Hetchy Regional Water System.

California is experiencing extreme drought conditions. Though San Franciscans initially responded our request to reduce water use by 10 percent, consumption is now on the rise and the voluntary conservation reductions are not being met. Intermittent spring rains provided a little relief, but it wasn’t enough. Another dry winter will put our Hetch Hetchy regional water supplies at serious risk.

To learn more, please read our updated press release.

Original announcement press release.

Visit our Water Conservation section to read more about how you can help meet the 10% voluntary reduction goal and find answers to some of our most frequently asked questions about the drought.

About the Hetch Hetchy Regional Water System

The Hetch Hetchy Regional Water System, operated by the San Francisco Public Utilities Commission, provides water to 2.6 million residents in four Bay Area counties. Two thirds of this water is provided to wholesale customers serving communities in Alameda, Santa Clara and San Mateo counties, with the remaining one third serving the residents and businesses of San Francisco. The Bay Area Water Supply and Conservation Agency (BAWSCA) represents our 1.7 million wholesale customers.

Our regional water system relies on snowfall and rainfall collected in the Hetch Hetchy, San Mateo Creek, and Alameda Creek watersheds. The Sierra snowpack is particularly critical to our water supply as snow serves as an additional water storage mechanism during the winter months, providing snowmelt water as the weather warms.

Current Water System Status

As a regional water provider, we carefully monitor precipitation conditions throughout the water year (Oct 1- Sept 30), particularly during the winter months when the majority of precipitation occurs and the mountain snowpack accumulates.

Historically, more than 63% of our annual precipitation and snowfall has occurred in the months of January through May.

Current System Storage and Precipitation information for the system can be found here:

Previous Water Reduction Requests

We last issued a 10% voluntary reduction request to our retail customers in April 2007. Dry-winter conditions continued in 2008 and the request remained in place until 2009.

At the time, 2007 was one of the driest winters on record, setting the stage for reduced water storage levels and possible first year drought conditions.  The call for voluntary cutbacks effectively reduced overall water consumption by 12%, exceeding the goal and avoiding mandatory rationing.

Low Residential Water Use in San Francisco

San Francisco’s gross water use is about 88 gallons per capita per day (gpcd),  less than one half the statewide average of 197 gpcd. Gross per capita reflects total water deliveries by a water agency (as measured by service area meters) divided by total population and includes residential, commercial, industrial and other water uses.

San Francisco's residential water use is about 49 gpcd. Residential per capita is the total water sales (measured by residential meters) divided by total population. Gallons per capita per day tells us the number of gallons of water used per person per day. Climate, land use, population density and other factors can cause significant variation in gpcd among regions.

Even though San Francisco has low per capita water usage, the SFPUC continues to aggressively pursue water conservation as the best means to protect our vital water supply. Through active conservation and plumbing code requirements, we forecast the potential to reduce water demands by 14 million gallons per day (mgd) by 2018 and 23 mgd by 2035.   

 Drought Planning 

With 2.6 million customers relying on the Hetch Hetchy Regional Water System, we carefully manage our water supply; plan for its future availability, and develop alternative water supplies to supplement and serve our regional water needs.

We plan water deliveries anticipating that a drought more severe than the worst drought ever experienced may occur. For example, the 1987-92 drought defines the most extreme recorded drought for regional system water deliveries, and establishes the basis for our ‘Design Drought’. This particular drought covered a 6½-year period from July 1986 (when the SFPUC reservoirs were full) to November/December 1992 (when the SFPUC reservoirs reached minimum storage).

All of our supply decisions and water reduction scenarios take into account water supply planning over multiple years and in consideration of our worst drought.

More information is outlined in our most current UWMP for the City and County of San Francisco found at:

Water Supply Diversification and Conservation Efforts

As an essential element of our water supply and drought planning efforts, we are diversifying our local water supplies by advancing groundwater, recycled water, non-potable water projects that maximize our supplies while putting all available water to its best use.

For more details please see our Water Resources Fiscal Year 2012 – 2013 Annual Report. 

Last updated: 6/20/2014 3:13:35 PM