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. The update reflects major advancements in rainfall data, mapping technology, digital engineering tools, and flood modeling software developed over the past four decades.
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.