Supervisors hear progress on Emergency Firefighting Water System; two reports due in June

San Francisco supervisors on Jan. 21 heard progress reports from the San Francisco Public Utilities Commission (SFPUC), the Fire Department and the Budget and Legislative Analyst Office on efforts to expand the city’s Emergency Firefighting Water System (EFWS), including neighborhood-by-neighborhood hydraulic modeling and a feasibility study of seawater pump stations. Departments said two reports are due to the Board by June 30, 2021, and a comprehensive citywide EFWS plan is planned for presentation by Dec. 31, 2021.

The EFWS is a high-pressure, post-1906 earthquake–era network fed primarily by the Hetch Hetchy regional system with two seawater pump stations as secondary sources, John Scarpulla of the SFPUC told the committee. Scarpulla said teams have replaced the older 45 Fire Response Areas with 50-acre grid cells for finer analysis, added building-inventory and vegetation inputs, and are running thousands of earthquake-and-weather scenarios to model fire demand for 2020, 2030, 2040 and 2050.

"The more you have of [water] sources, the better," Scarpulla said, arguing Lake Merced and Sunset Reservoir can be used quickly while seawater pump stations would take longer to permit and build.…