Flood Control District modernizes county hydrology standards

"San Bernardino County Update", yellow arrowhead and "SBCounty.gov

Cover page of a San Bernardino County Flood Control District hydrology report on a wooden desk. — *San Bernardino County Flood Control District hydrology report* *prepared for a flood control project.*

The San Bernardino County Flood Control District is updating its Hydrology Manual — the primary guide used to design storm drains, flood channels, detention basins and other flood control infrastructure throughout the county.

Originally published in 1983, the manual serves as the foundation for how engineers study rainfall, drainage and flood risks when planning public and private projects. Manuals of this type are intended to function as long-term engineering standards and are updated as needed. The manual incorporates decades of advancements in rainfall science, mapping technology, digital engineering tools, and flood modeling practices to support more accurate and resilient stormwater and flood control planning.

The revised manual also includes new guidance for post-wildfire flooding, sediment and debris flow analysis, and modern engineering standards that improve flood resiliency and public safety.

For the public, this means stronger and more consistent flood protection planning across San Bernardino County. The update will help agencies, engineers and developers design infrastructure that better prepares communities for changing weather conditions and future growth.

The updated Hydrology Manual and supporting digital resources can be viewed at Hydrology Manual – Public Works.

The modernization effort represents an important step toward safer communities and more transparent, efficient flood control planning countywide.

Additional County Update News – May 28, 2026