Bay Area Public Water and Wastewater Utilities Build Advanced Radar Network by San Francisco Public Utilities Commission Mar 26, 2026 Member Submitted News SAN FRANCISCO — The San Francisco Public Utilities Commission (SFPUC), along with a coalition of other Bay Area water, wastewater, and flood control agencies, is taking action to put new weather radar technology to use, bringing advanced precipitation observations and forecasts to California. This advanced network works like a magnifying glass, giving agencies and the communities they serve a clearer, real-time view of atmospheric rivers and rainfall intensity. It helps show where the heaviest rain will fall. This improved data enables public agencies and communities to prepare and respond when dangerous storms approach the coast. And, in our drought-prone state, it provides water agencies pinpointed data to maximize water supply reservoir storage. This system, known as Advanced Quantitative Precipitation Information, or AQPI, was developed through a decade-long local, state, and federal agency collaboration working with key researchers to improve monitoring of extreme weather events within the Bay Area’s complex terrain. In areas shaped by hills, valleys and coastal mountains, traditional weather radar can miss critical details where heavy rain is developing. The San Francisco Bay Area AQPI Network uses five X-band radar installations positioned around the region to provide a much sharper picture of where rain is falling with updates every one to two minutes. This means the system can focus much closer to the ground and capture fine-scale rainfall details that broader, long-range radar systems miss. The X-band radar installations are in Contra Costa, San Mateo, Santa Clara, Santa Cruz, and Sonoma counties. Critical funding for the radar installations was provided by the California Department of Water Resources in the form of a $19.7 million grant. This AQPI network also includes a larger C-band radar placed on Mount Barnabe in western Marin County, facing the Pacific Ocean. This radar helps track storms as they approach the coast and complements the X-band radars by providing a broader view of incoming systems before they move inland. The AQPI radar systems were built, deployed and are currently operated by the Cooperative Institute for Research in the Atmosphere (CIRA) at Colorado State University. CIRA is a NOAA Cooperative Institute, a key partner in the AQPI project, and produces AQPI radar products that support decisions by Bay Area agencies. “Critical infrastructure like our water and emergency response systems keep San Francisco running every day,” said Mayor Daniel Lurie. “This regional radar system will give the San Francisco Public Utilities Commission the tools they need to make timely decisions, manage San Francisco’s stormwater effectively, and keep San Francisco neighborhoods and families safe during a storm.” “Our sewer system is at the forefront protecting public health and the environment, and 2.7 million people in the Bay Area also depend on us to deliver high-quality drinking water around the clock,” said Dennis Herrera, SFPUC General Manager. “This advanced radar system gives us more precise, real-time storm data so we can better manage stormwater and our reservoirs before and during major storms. Earlier and more accurate information helps us make critical operational decisions that strengthen reliability for the communities we serve.” “This work started with a question about how advances in science can better support people making decisions during dangerous storms,” said Marty Ralph, Director of the Center for Western Weather and Water Extremes at UC San Diego’s Scripps Institution of Oceanography. “AQPI represents years of research coming together in a regional radar system designed for the Bay Area’s unique topography, capturing details that standard radar often misses and turning that research into practical forecasts for water and emergency agencies.” “AQPI represents the successful transition of cutting-edge atmospheric research into operational capability,” said NOAA Acting Chief Scientist Steven Thur, the Assistant Administrator for NOAA Oceanic and Atmospheric Research. “It demonstrates how sustained scientific innovation can directly improve hazard preparedness, water management, and community resilience.” “This is a regional approach to water management understanding that we have to get the most out of each storm that comes across California,” said Mike Anderson, State Climatologist with the California Department of Water Resources. “Having the right information at the right time enables the opportunity to maximize benefit while mitigating hazard. The AQPI collaboration delivers key information to the Bay Area for this purpose.” “People rely on accurate forecasts to make decisions about staying safe during extreme weather,” said Mark Tamayo, KTVU meteorologist. “AQPI gives weather experts a clearer picture of what’s happening in your community and helps meteorologists share more timely, useful information that supports you and your family’s safety.” “In the Russian River watershed, we’ve seen storms turn streets into rivers within hours,” said Sonoma County 2nd District Supervisor David Rabbitt. “We have to keep improving how we track and understand these storms, and AQPI is an important step toward giving local agencies and emergency responders the information they need to prepare.” AQPI is a regional project funded by the California Department of Water Resources and developed in collaboration with local, state and federal partners. Participating agencies include water utilities, flood control districts, and research institutions. The system also integrates a radar installation in Santa Cruz County. Participating agencies include: Alameda County Flood Control District; Alameda County Water District; Contra Costa County Flood Control District; East Bay Dischargers Authority, San Lorenzo; East Bay Municipal Utility District; Marin County Public Works; San Francisco Public Utilities Commission; Santa Clara Valley Water; Sonoma County Water Agency; Zone 7 Water Agency, Livermore. Project partners include: California Department of Water Resources (DWR); Cooperative Institute for Research in the Atmosphere (CIRA); National Oceanic and Atmospheric Administration (NOAA); University of California San Diego, Scripps Institution of Oceanography, Center for Western Weather and Water Extremes (CW3E). About the San Francisco Public Utilities Commission The San Francisco Public Utilities Commission is a department of the City and County of San Francisco. It delivers drinking water to 2.7 million people in the San Francisco Bay Area, collects and treats wastewater for the City and County of San Francisco, and meets 75% of the electricity demand in San Francisco with clean energy. The SFPUC’s mission is to provide customers with high-quality, efficient and reliable water, power, and sewer services in a manner that values environmental and community interests, and sustains the resources entrusted to the agency’s care. Learn more at sfpuc.gov.
