Duncan Creek Diversion Improvement Project

16 Documents in Project


SCH Number
Lead Agency
Placer County Water Agency
Document Title
Duncan Creek Diversion Improvement Project
Document Type
NOD - Notice of Determination
Document Description
The proposed project is limited to improvements to the existing Duncan Creek Diversion Dam to allow sediment to pass downstream and to implement instream flow and pulse flow requirements associated with the license for the PCWA’s Middle Fork American River Project (MFP), which was issued by the Federal Energy Regulatory Commission (FERC) on June 8, 2020 (FERC Project No. 2079). Specifically, the project is designed to modify the diversion such that the existing diversion pool will permanently fill with sediment, allowing natural stream sediment (and large woody debris) transported from upstream during high flow events to pass downstream of the diversion. This natural sediment transport is intended to benefit the biological functioning of the stream (e.g., spawning gravel supply). PCWA proposes to modify the existing diversion dam to include a new diversion facility on the southern portion of the diversion dam to divert water into the tunnel. The new diversion facility will include: new diversion approach channel and gated notch designed to generate adequate hydraulic head to divert water and a path to pass sediment through the crest gates of the diversion dam; new infrastructure for the diversion and screening of water to the Duncan Creek – Middle Fork Tunnel Intake; new fish bypass and receiving pool that will provide fish passage downstream of the diversion dam; new instream flow piping designed to allow PCWA to meet the new minimum instream flow and pulse flow requirements; and new micro-hydro facility that will generate power to operate various components of the diversion facility.

Contact Information

Patrick Moeszinger
Agency Name
Department of Fish and Wildlife
Job Title
Senior Environmental Scientist (Specialist)
Contact Types
Responsible Agency


Northern California
Other Location Info
The project is located off the gated Duncan Creek Diversion Dam Road, accessible via Mosquito Ridge Road approximately 20 miles northeast of the community of Foresthill.

Notice of Determination

Approving Agency
California Department of Fish and Wildlife
Approving Agency Role
Responsible Agency
Approved On
County Clerk
Final Environmental Document Available at
the office location listed above for the Lead Agency. CDFW’s record of execution of the above Lake and Streambed Alteration Agreement as Responsible Agency is available at CDFW’s regional office.


(1) The project will have a significant impact on the environment
(2a) An Environmental Impact Report was prepared for this project pursuant to the provisions of CEQA
(2b) A Mitigated or a Negative Declaration was prepared for this project pursuant to the provisions of CEQA
(2c) An other document type was prepared for this project pursuant to the provisions of CEQA
(3) Mitigated measures were made a condition of the approval of the project
(4) A mitigation reporting or monitoring plan was adopted for this project
(5) A Statement of Overriding Considerations was adopted for this project
(6) Findings were made pursuant to the provisions of CEQA


Notice of Determination

Disclaimer: The Governor’s Office of Planning and Research (OPR) accepts no responsibility for the content or accessibility of these documents. To obtain an attachment in a different format, please contact the lead agency at the contact information listed above. You may also contact the OPR via email at state.clearinghouse@opr.ca.gov or via phone at (916) 445-0613. For more information, please visit OPR’s Accessibility Site.

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