About the Urban Watershed Assessment
The Urban Watershed Assessment is the watershed-based planning process the SFPUC is using to help plan the City’s Sewer System Improvement Program (SSIP), a 20-year, multi-billion dollar project to improve the collections portion of our combined sewer system.
San Francisco has eight distinct urban watersheds, five on the Bayside (North Shore, Channel, Islais, Sunnyvale, and Yosemite) three on the Westside (Richmond, Sunset, and Lake Merced). This assessment promotes progressive solutions considering unique characteristics of each of the City’s urban watersheds, such as soil type, underlying geology, age of infrastructure and urban development patterns.
UWA recommendations will include a blend of innovative green (rain gardens, permeable pavement, bioswales) and traditional grey (tunnels, pump stations, upstream conveyance pipes) infrastructure projects, incentive programs and policies to meet our sewer system challenges. The recommendations will shape the next generation of sewer improvements to provide a compliant, reliable, resilient, and flexible system that can respond to catastrophic events, manage stormwater and flooding, adapt to climate change, and provide community benefits and environmental sustainability.
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System Challenges
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Aging Infrastructure
Over 80% of San Francisco sewer pipes are over 100 years old and the system gets overwhelmed during heavy rains.
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Seismic Vulnerability
Our sewer system was not built to withstand a major earthquake and facilities are seismically vulnerable.
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Climate Change
The increasing intensity and frequency of storms can overwhelm our system and contribute to flooding.
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Odor Control
Odors can be a problem when aging equipment malfunctions and during dry weather. |
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Water Quality
Continue to reduce combined sewer discharges to help improve water quality in the Bay and Ocean.
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Localized Flooding
Stormwater runoff can overwhelm our system during heavy rains and lead to neighborhood flooding.
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Urban Watershed Assessment Process
The Urban Watershed team has completed numerous techincal studies and has engaged San Francisco through a variety of outreach efforts since 2011. Check out the reports and recordings below for Bayside and Westside planning activities. Learn more about the History of SF Urban Watershed Planning.
Bayside Urban Watersheds Documents
Below are reports and webinars from the Characterization and Opportunities Phases of work for the North Shore, Channel, Islais Creek, Yosemite, and Sunnydale Watersheds.

Technical Reports
Public Meetings and Materials
Westside Watersheds Documents
Below are reports and webinars from the Characterization and Opportunites Phases of work for the Richmind, Sunset, and Lake Merced Watersheds.

Technical Reports
Public Meetings and Materials
Get Involved
Check out the SFPUC calendar for upcoming Green Infrastructure and other SSIP events coming to your neighborhood!
Stay informed by subscribing to our e-newsletter to learn about upcoming sewer and urban watershed events and projects. Sign up here: sfwater.org/signup.