TMWA Donner Lake Outlet Emergency Cleanout Project
- SCH Number
- Lead Agency
- Fish & Wildlife 2 (Rancho Cordova) (California Department of Fish and Wildlife, Region 2)
- Document Title
- TMWA Donner Lake Outlet Emergency Cleanout Project
- Document Type
- NOE - Notice of Exemption
- Document Description
- CDFW has executed Lake and Streambed Alteration Agreement No. 1600-2017-0324-R2, pursuant to Section 1602 of the Fish and Game Code to the Truckee Meadow Water Authority, Bill Hauck. The purpose of the project is to regain lost outlet channel capacity to its original capacity to minimize the risk of flood of Donner Lake and the lakefront properties. Since the lake is not draining adequately, the Permittee proposes to return Donner Lake outlet channel back to its original working capacity by removing the accumulated sediment and debris that is casing reduced outlet flows. An estimated 6,500 cubic yards of sediment and debris will be removed down to an elevation of 5,924 feet. Project will require dewatering of the channel above the dam, including the portion of the channel within Donner Lake. No in water will be conducted. A temporary inflatable coffer dam will be installed at the head of the channel to obstruct flows from Donner Lake. Dewatering will be accomplished b surface pumps and possibly dewatering wells. Water will be pumped below the dam through a temporary pipe. An additional bypass pipeline may be installed to divert water around the project and allow for continuous flow to Donner Creek, if water is flowing in the creek. Removal of the sediment will be accomplished by excavating the accumulated sediment using front-end loaders, excavators, dump trucks, and drag lines. Sediment and vegetation will then be loaded into a dump truck and transported offsite. Once the sediment removal is complete, the coffer dam will gradually be deflated and removed, restoring flows to the channel at a rate that will allow sediment to settle. Temporary impacts to Donner Lake and the channel total 1.5 acres for the temporary access ramp, construction, cofferdam, and pipeline installation, and 1 acre of impacts due to the maintenance dredging. Channel excavation is expected to take two weeks to complete, and the overall construction period will occur over 4 weeks surface.
- Contact Information
California Department of Fish and Wildlife, Region 2
Northern Central Region 1701 Nimbus Road, Suite A
Rancho Cordova, CA 95670
Phone : (916) 358-2842
- 39°19.344'"N 120°14.296'"W
Notice of Exemption
- Exempt Status
- Statutory Exemption
- Type, Section or Code
- Reasons for Exemption
- Project involves the emergency repairs to publicly or privately owned service facilities necessary to maintain services essential to public health, safety and welfare. The project involves a specific action necessary to prevent or mitigate an emergency.
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