Hydrograph Standards

Hydrograph Requests

The Hydrograph Request document (PDF) contains instructions on how to measure the parameters for our unit hydrograph method. Our normal procedure is for hydrograph requests to be sent to us for us to review the input parameters before serious modeling is performed. This can save the engineer or hydrologist from having to redo the hydrology modeling for their project.

Draft Standard Documents

The following documents are drafts of select Contra Costa County Flood Control & Water Conservation District (FC District) standards that are in review. They contain pertinent and useful information, but could contain technical or typographical errors. Please contact Mark Boucher if you find an to report any errors.

HEC-HMS Guidance (PDF) 2017-07-25 (PDF - 2947 KB) - Latest revisions: Added appendix discussing the use of DSS files and HEC-DSSVue.

Further information on the parameters used in the FC District’s unit hydrograph method can be found under "Hydrology Requests" above.

HMS Template Model (Draft)

The FC District has a template HEC-HMS model that is setup to run the FC District’s hydrograph method. A draft of this template model can be found through the link below. Download Version 4.2.1.

FCD_HMS_Template 2018-07-03 (zip - 224 KB)  - [Version 4.2.1] Unzip the downloaded folder to your project file location, open it in HEC-HMS, and rename it as appropriate.

This zip file now contains an Excel file to aid in calculating Tlag and and rain depths based on MSP.

Guidance on the use of this template and how the FC District’s standards are set up in the HMS model is provided in the section above under "HEC-HMS Guidance" above.