Hell Hole Dam Core Raise Project

3 Documents in Project

Summary

SCH Number
2016052036
Lead Agency
Placer County Water Agency
Document Title
Hell Hole Dam Core Raise Project
Document Type
NOD - Notice of Determination
Received

Document Description
At the request of the California Department of Safety of Dams (DSOD), PCWA Investigated the permeability of Hell Hole Dam above the impervious dam core in the event of a Probable Maximum Flood (PMF). The PMF is the theoretically largest flood resulting from a combination of the most severe meteorological and hydrologic conditions that could conceivably occur in a given area. Investigations identified that the PMF over tops the dam core for a distance fo approx. 700 feet adjacent to the left abutment and approx. 700 feet adjacent to the left abutments and approx. 700 feet adjacent to the right abutment. To meet DSOD and Federal Energy Regulatory Commission (FERC) requirements, PCWA is proposing to raise the dam core to ensure that seepage that could occur above the core under PMF loading is safely controlled.

Contact Information
Jon Mattson
Placer County Water Agency
PO Box 6570
Auburn, CA 95604

530-823-4886

Location

Counties
Placer
Cross Streets
Forest Rd 2 and Hell Hole Dam and Powerhouse Rd
Waterways
Hell Hole Reservoir, Rubicon River, NFLC Creek
Township
14N
Range
14E
Section
16
Other Location Info
Foresthill

Notice of Determination

Approving Agency
Placer County Water Agency
Approving Agency Role
Lead Agency
Approved On
Final EIR Available Location
144 Ferguson Road, Auburn, CA 95603

Determinations

(1) The project will have a significant impact on the environment
No
(2a) An Environmental Impact Report was prepared for this project pursuant to the provisions of CEQA
No
(2b) A Negative Declaration was prepared for this project pursuant to the provisions of CEQA
Yes
(3) Mitigated measures were made a condition of the approval of the project
Yes
(4) A Statement of Overriding Considerations was adopted for this project
No
(5) Findings were made pursuant to the provisions of CEQA
No
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