To accompany changes to physical features of Folsom Dam, the U.S. Army Corps of Engineers (USACE), Sacramento District (SPK) will develop a new Water Control Manual (WCM). This new water control manual includes a water control diagram---a strategy to guide flood operations. To develop the water control diagram, proposed operation rules must be tested against a wide range of events, including both historical flood events and design events not seen in the historical record.

To produce the numerous design events and to characterize historical events efficiently, we developed the Hydrograph Balancing and Reporting Tool (HyBART). Given a family of flow-duration-frequency curves, HyBART automates development of balanced hydrographs. The user specifies a set of frequencies, a set of historical event patterns, and a set of durations that the hydrographs should be balanced to. HyBART queries the flow-duration-frequency curves and scales the hydrographs for the multiple event patterns to match the volume associated with the multiple durations for the multiple frequencies. This automation greatly expedites development of inputs for reservoir operation analysis, or other studies, and eliminates human error.

To develop and implement HyBART, we:

  1. Identified and analyzed the project requirements.
  2. Designed a prototype.
  3. Wrote the code.
  4. Tested the software.
  5. Documented the source code.
  6. Produced a user’s manual.
  7. Deployed the application.

As a result of this project, SPK now has a tool that:

  • Queries flow-duration-frequency values for durations between 0 and 365 days, interpolating between durations and frequencies as necessary.
  • Analyzes the frequencies of flows and corresponding durations for associated hydrograph patterns.
  • Creates balanced hydrographs for multiple durations based on hydrograph patterns and frequencies.