The Westborough Water District (District) owns the water and sanitary sewer system which serves the Westborough area of South San Francisco. We are located in northern San Mateo County, about 9 miles south of San Francisco. The District serves primarily residential community with three small shopping centers. The District’s boundary encompasses about 1 square mile of land. The District provides water and sewer service to a population of 12,481 through 3,882 service connections. The population was calculated using the Department of Water Resources population tool.

The District was formed in 1961 under the County Water District Act of California. The District contracts with the San Francisco Water Department to purchase water wholesale from the San Francisco Public Utility Commission. With regard to the sanitary sewer system, the District contracts with the City of Daly City (North San Mateo County Sanitation District or NSMCSD) for general maintenance, emergency response, collection and treatment. The District does not physically perform any of the maintenance, repairs or treatment of the sanitary sewer system as those responsibilities are conducted by agreement through the NSMCSD.

The District has three sewer lift stations which pump sewage from the District to the NSMCSD’s treatment plant. The Avalon Sewer Lift Station has two pumps and both the Westborough and Rowntree Lift Stations have three pumps at each station. The District’s sanitary sewer flow averages approximately 598,000 gallons per day during wet weather compared to 648,000 gallons during dry weather. This District has 20 miles of gravity sanitary sewer mains and a three-quarter mile of sewer force main. Since 2010 the District has had only one sanitary sewer overflow that was attributed to an electrical power failure.

Sewer System Management Plan (SSMP) Reporting

The 2015 Sewer System Management Plan (SSMP) has been prepared by the General Manager with the assistance of a District Consultant.

Click here to download the Biennial Report of Sanitary Sewer System Overflows for the Period of January 1, 2016 through December 31, 2017 (PDF).

WWD Ten-Year Sewer History Rates

Fiscal Year NSMCSD Our Rate Increase
2008-2009 $4.82 $5.27 $0.24[1]
2009-2010 $4.82 $5.73 $0.46[2]
2010-2011 $4.82 $5.73 $0
2011-2012 $4.82 $5.73 $0
2012-2013 $4.82 $5.73 $0
2013-2014 $5.26 $6.17 $0.44
2014-2015 $5.74 $6.87 $0.70[3]
2015-2016 $6.26 $7.52 $0.65[4]
2016-2017 $6.76 $8.02 $0.50
2017-2018 $7.30 $8.87 $0.85[5]


[1] Includes WWD increase of 24 cents; from 21 cents to 45 cents
[2] Includes WWD increase of 46 cents; from 45 cents to 91 cents
[3] Includes WWD increase of 22 cents; from 91 cents to $1.13
[4] Includes WWD increase of 13 cents; from $1.13 to $1.26
[5] Includes WWD increase of 31 cents; from $1.26 to $1.57