Devil's Gate Sediment Removal and Management Project (Lake or Streambed Alteration Agreement No. 1600-2015-0263-R5)
9 Documents in Project
Summary
SCH Number
2011091084
Lead Agency
Los Angeles County Flood Control District
Document Title
Devil's Gate Sediment Removal and Management Project (Lake or Streambed Alteration Agreement No. 1600-2015-0263-R5)
Document Type
NOD - Notice of Determination
Received
Posted
3/21/2017
Present Land Use
Open Space
Document Description
CDFW has executed Lake and Streambed Alteration Agreement No. 1600-2015-0263-R5, pursuant to section 1602 of the Fish and Game Code to the project Applicant, LA County Flood Control District.
The purpose of the Devil's Gate Reservoir Sediment Removal and Management Project (Project) is to remove sediment and manage future inflows of sediment to maintain capacity of the Devil's Gate Reservoir (Reservoir). Sediment levels have accumulated above elevations levels in Devil's Gate Reservoir that create operational and safety risk for Devil's Gate Dam and Reservoir.
Project need for the Dam is to safely make controlled releases to 5,500 feet per second through the outlet valve and tunnel gates for storm events that are less than or equal to Dam's 50-year design storm (also known as 2% return interval event). The 50-year design storm is defined by LA County Dept. of Public Works Hydrology Manual and used by Permittee to comply with LA county Flood Control Act objectives.
The Project need for the Reservoir is to have sufficient capacity to contain the 50-year storm even and/or have capacity sufficient for 2 Design Debris Events (DDE) or 4 million cubic yards (CY) in event of a future inflow of a large sediment inflow. The DDE is defined by LA County Dept. of Public Works Sedimentation Manual and used by Permittee to comply with LA county Flood Control Act objectives. As a result of sediment deposition following the 2009 Station Fire, the available capacity in the Reservoir is less than one DDE. Therefore, sediment removal is required to maintain flood control capacity of 4.0 million CY (two DDE's) below the spillway elevation of 1,040.50 feet above mean sea level. In order to achieve the Project purposes the Permittee proposes three (4) distinct project phases including initial sediment removal, routine maintenance, habitat restoration, and Dam Operations.
Contact Information
Name
Matthew Chirdon
Agency Name
CDFW
Contact Types
Lead/Public Agency
Phone
Location
Coordinates
Cities
Pasadena
Counties
Los Angeles
Cross Streets
Oak Grove Drive and Windsor Drive
Total Acres
120
Parcel #
5823031900
State Highways
Hwy 210, 2
Schools
La Canada HS
Waterways
Arroyo Seco
Notice of Determination
Approving Agency
CDFW
Approving Agency Role
Responsible Agency
Approved On
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
Yes
(2b) A Mitigated or a Negative Declaration was prepared for this project pursuant to the provisions of CEQA
No
(2c) An other document type was prepared for this project pursuant to the provisions of CEQA
No
(3) Mitigated measures were made a condition of the approval of the project
Yes
(4) A mitigation reporting or monitoring plan was adopted for this project
N/A
(5) A Statement of Overriding Considerations was adopted for this project
No
(6) Findings were made pursuant to the provisions of CEQA
Yes
Disclaimer: The document was originally posted before CEQAnet had the capability to host attachments for the public. To obtain the original attachments for this document, 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.