Lower Alemany Area Stormwater Improvements Project

The San Francisco Public Utilities Commission operates a combined sewer system that collects and treats San Francisco's wastewater (sewage and stormwater). We are upgrading and modernizing our system so that we can continue to protect public health and the environment. One key area of investment includes enhancing flood resilience across the City through operational improvements, capital projects, and community resources to help the public prepare for and recover from intense but inevitable storm events.

The Lower Alemany area is part of the Islais Creek watershed that historically transported stormwater from Glen Canyon, Outer Mission, and the Excelsior to the Bay. Like many parts of San Francisco, over time, the creek and the low-lying Alemany area were covered with streets, homes, and businesses, preventing much of this water from flowing to the Bay. The Lower Alemany Stormwater Improvements Project will increase collection system capacity and reduce the risk of flooding by constructing a new tunnel and box sewer.

Project Details
The project proposes to construct a 10-foot diameter pipe underground from Stoneybrook Avenue to Industrial Street via Alemany Boulevard, Gaven and Boutwell streets to increase the capacity of our system to transport wastewater. Construction would involve three portals or shafts to construct the tunnel, other sewer connections, and related improvements in the area. See Area Map.

Project Status as of Early 2026
The project is reevaluating a very competitive construction and tunneling landscape and we will be re-engaging with the contracting community. We will keep you updated on progress and the project timeline as this process progresses. We anticipate sharing another update in late Spring 2026.

Resources for Flood Resilience
It is important to note that even after project completion, this area will still be at risk of flooding during heavy rains. Residents and business owners in these areas are encouraged to visit sfpuc.gov/rainreadysf, which provides information about planning, preparing, and protecting properties during storms.