HYDROLOGY MANUAL (2026) EDITION
The 2026 Edition of the Hydrology Manual serves as a comprehensive guide for hydrologic studies within San Bernardino County. The manual includes current standards, procedures, examples, and maps. Hydrology Manual (2026 Edition) (PDF)
HYDROLOGY MANUAL MAP VIEWER
This interactive GIS viewer application allows users to explore and search the following datasets:
- Hydrologic Soil Groups
- Antecedent Moisture Condition (AMC)
- Areas requiring special analysis under representative burn conditions
- Areas requiring sediment/debris analysis under typical conditions
- Precipitation isohyet maps
These datasets correspond to the figure maps included in the Hydrology Manual PDF.
HYDROLOGY MANUAL SUPPORT FILES
The ZIP file includes the same datasets available in the Maps Viewer, provided in Shapefile format.
Additional supporting tools include:
- Rational Method Tool (for small projects)
- Unit Hydrograph HEC-HMS Pre-Processor Tool
- Post-Fire CN Adjustment Tool
- Sediment-Debris Yield and Bulking Tool
- Hydrology Manual HEC-HMS User Guide (PDF)
The information contained in these files should be used in accordance with the methods, standards, and procedures outlined in the 2026 Edition of the Hydrology Manual.
Hydrology Manual Maps – Shapefiles.ZIP
Hydrology Manual Maps – CAD.ZIP
Unit Hydrograph HEC-HMS Pre-Processor Tool
Sediment-Debris Yield and Bulking Tool
Software Requirements for Drainage Report and Permit Applications
In addition to the supporting tools listed above, projects requiring complex hydraulic or hydrologic modeling should adhere to the following software:
Accepted Hydrologic Software:
- Advanced Engineering Software (AES)
- CivilDesign Software
- HEC-HMS (Hydrologic Engineering Center – Hydrologic Modeling System)
Accepted Hydraulic Software:
- Los Angeles County WSPG program
- HEC-RAS (Hydrologic Engineering Center – River Analysis System)