Mule Creek Dam Reservoir Inundation Mapping
« All Projects

Mule Dam is located near the city of Ione, in Amador County, California. The 540 acre-feet reservoir holds treated effluent from nearby Mule Creek State Prison (MCSP).

Classified as a high-hazard potential dam (HHPD) by the California Division of Safety of Dams (DSOD), the failure of this structure would likely cause significant damage and loss of human life. The project's objective was to evaluate the impacts of a potential breach. Information from the study was used to update the dam's Emergency Action Plan (EAP).

Geosyntec's Scope of Services

Geosyntec performed a dam breach analysis and inundation mapping study to update the EAP. Geosyntec developed a two-dimensional model using HECRAS 2D to simulate the flood inundation resulting from the CSP Mule Creek Dam breach. The dam breach analysis and inundation mapping were done in accordance with the California Code of Regulations for Inundations Mapping and the Federal Emergency Management Agency (FEMA) guidelines for inundation mapping.

The study included data acquisition, model grid setup, parameterization, simulation execution, results evaluation, and inundation mapping. Two hypothetical worst-case dam breach scenarios were modeled as per the regulatory requirements: A sunny-day breach from an upward extended piping failure which occurs when the initial dam water level is at peak level during dry weather; and a storm-induced failure scenario when an overtopping failure breach extends downward from the top of the dam at the peak stage during an extreme rain event.

Geosyntec is also managing the Owner's Dam Safety Program (ODSP) external audit for Valley Water. The Dam Safety Program (DSP) external audit is a Federal Energy Regulatory Commission (FERC) requirement, separate from the part 12D safety review, conducted by an independent reviewer for owners of one or more high-hazard dams.

Notable Accomplishments

Geosyntec conducted the necessary steps for the dam breach analyses, inundation mapping, and EAP update. The updated EAP will be used to aid emergency authorities in the event of a dam breach.