Hydrology Section staff collects and analyzes precipitation and runoff data. They maintain rainfall and stream gauges and equipment. Staff also prepares hydrological analysis of watersheds, data, and engineering charts for use in project development

Services Provided

The Hydrology Section provides the following services:


  • Collection and reporting of rain and stream gauge data from District gauges
  • Hydrologic data analysis
  • Maintenance of rain and stream gauges
  • Determination of flow design rate flow rates for: 2-, 5-, 10-, 25-, 50- and 100-year flows
  • Review of flow rates and model provided by others
  • Production of hydrographs using our specific unit hydrograph method.
  • Review of proposed watershed modifications such as:
    • Mitigation of increased impervious surface not planned for in current Drainage Area land use maps
    • Proposed revisions and updates to Drainage Area Plans
  • Review of hydrologic impacts of watershed changes to existing hydrologic model
  • Collection of published data from EBMUD, National Weather Service, US Army Corps of Engineers, and other agencies gauge data
  • Frequency and correlation analysis of collected data
  • Analysis and reporting of major storm events for understanding of the storms statistical return period

HMS Guidance and Template Model

The FC District has written a draft guidance on how to use the FC District method in HMS. We have also built a template HEC-HMS model that uses FC District methods. The HEC-HMS Guidance document and HMS Template are available through links on our Hydrograph Standards page.