Hayfork Creek Domestic Diversion and Hayfork Creek Tributary Stream Crossing Improvements (Lake or Streambed Alteration Agreement EPIMS-TRI-11073-R1I)
168 Documents in Project
Summary
SCH Number
2018122049
Lead Agency
Trinity County
Document Title
Hayfork Creek Domestic Diversion and Hayfork Creek Tributary Stream Crossing Improvements (Lake or Streambed Alteration Agreement EPIMS-TRI-11073-R1I)
Document Type
NOD - Notice of Determination
Received
Posted
4/23/2024
Document Description
Project 1 is limited to the decommissioning of a legacy, seasonal onstream impoundment on an ephemeral tributary to Hayfork Creek. An existing 36-inch corrugated metal pipe (CMP) is set approximately 7-feet above the natural grade of upstream channel conditions, within the prism of an earthen embankment, and acts as a culverted spillway at the outlet of the impoundment. A vertical overflow pipe approximately 2-inches in diameter passes limited flows downstream of the impoundment. The existing CMP will be removed, and approximately 75-cubic feet of earthen embankment will be excavated, impacting approximately 210-square feet of bed, bank, and/or channel, and a new 42-inch CMP will be set at proper grade and in alignment with the natural watercourse. Rock armoring will be applied at the inlet and outlet to protect against erosion and dissipate energy during stream flows. One oak tree may be removed over the course of completing project activities.
Project 2 is limited to the replacement of a culverted CMP crossing on an ephemeral tributary to Hayfork Creek. The existing CMP is 24-inches in diameter and undersized to adequately convey the flows of a 100-year storm event. The existing CMP will be replaced with a new 42-inch CMP set at the same grade and alignment as the existing culvert. Approximately 30-cubic feet of fill will be excavated, impacting approximately 200-square feet of bed, bank, and/or channel.
Project 3 is limited to the surface diversion of Hayfork Creek, an anadromous perennial stream, for domestic use only. The point of diversion (POD) is a 12-foot seep well cased with 42-inch concrete pipe set within the floodplain of Hayfork Creek. The diversion, as well as associated water storage and use, will adhere to a valid water right authorized by the State Water Resources Control Board.
Contact Information
Name
Helen Bowman
Agency Name
CDFW
Job Title
Environmental Scientist
Contact Types
Responsible Agency
Phone
Location
Cities
Hayfork
Counties
Trinity
Regions
Northern California
Parcel #
016-250-009-000 and 016-250-004-000.
Waterways
Hayfork Creek
Other Information
480 Old Haywagon Road and 1505 Hyampom Road, Hayfork, CA, 96041
Notice of Determination
Approving Agency
CDFW
Approving Agency Role
Responsible Agency
Approved On
County Clerk
Trinity
Final Environmental Document Available at
530 Main Street, Weaverville, CA 96093
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
Yes
(5) A Statement of Overriding Considerations was adopted for this project
No
(6) Findings were made pursuant to the provisions of CEQA
Yes
Attachments
Notice of Determination
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