HEALTHY DEVELOPMENT MEASUREMENT TOOL

Indicator ES.1.c Water use

Descriptive Title: Gross per capita water use

Geographic Unit of Analysis: County

Why Is This An Indicator Of Health and Sustainability?

Maintaining an adequate water supply is a basic necessity for health of individuals and communities. Sufficient water resources affect human health both directly and indirectly. Every person requires about 2 liters of clean drinking water each day. Water is also needed for many everyday activities, including personal hygiene (i.e. showers, sewage removal), dish washing, and laundry. Water resources are necessary for the success of agriculture and industry (e.g. irrigation, food processing, cooling, and mining). Water resources also affect the health of fisheries, indirectly affecting nutrition and the livelihood of those in the fishing industry. Lastly, adequate water resources are necessary for human recreational activities at lake and rivers.

Processing potable water is energy intensive and thus contributes to air emissions associated with fossil fuel energy combustion. Water conservation efforts, control of water pollution, and restricted use of potable water can all play a part in ensuring a safe and sufficient water supply.

Interpretation and Geographic Equity Analysis

Currently, San Francisco's gross water use is approximately 73.3 million gallons per day (mgd), or 91.5 gallons daily per capita. Approximately 62% of this total is delivered to San Francisco residential customers. Non-residential water use accounts for approximately 38% of the demand. Not shown here, unaccounted water amounts to approximately 9% of water use. The gross per capital water use has slowly declined over the last five years; this is primarily due to water efficiency in plumbing.

According to the 2005 Urban Water Management Plan, "Single-family units comprise approximately 33 percent of the total households in San Francisco, and use approximately 40 percent of the total water delivered to the residential sector. The remainder of residential water use (60 percent) occurs from multi-family units such as apartments. Due to the moderate climate and the high density housing in San Francisco, water use within the residential sector is used almost entirely indoors. For multi-family units, the average outdoor water use is considered negligible. For single-family residential units, the average, outdoor water use is less than ten percent of their total use."^a

Methods

Gross sales include total city paying and total city non-paying customers.  Residential sales include total city single family and multifamily paying customers.  These figures do not include unaccounted for water.  Per-Capita Water Use is estimated by dividing residential water consumption by city population. Gross Per-Capita Water Use is estimated by dividing gross water consumption by city population.  “Gpcd" = gallons per capita per day and "mgd" = million gallons per day.

Data Source

Water figures from SFPUC Monthly Sales Data. Water Use is presented by SFPUC Fiscal Year (July - June). Population estimates are from US Census Bureau.

Map and tables prepared by City and County of San Francisco, Department of Public Health, Environmental Health Section using ArcGIS software.

Map and table data is presented for the county. Detailed information regarding census data, geographic units of analysis, their definitions, and their boundaries can be found in the HDMT at the following links:

http://www.thehdmt.org/etc/Geographic_Units_of_Analysis.pdf

http://www.thehdmt.org/data_map_methods.php