SCH Number 2004062147

Project Info

Title

Lake 20 - Roadway Rehabilitation & Curve Realignment Project

Description

The California Department of Fish and Game is executing Lake or Streambed Alteration Agreement number 1600-2009-0045-R2, pursuant to Section 1602 of the Fish and Game Code to the project applicant, California Department of Fish and Game. Caltrans proposes to stabilize a section of the Grizzly Creek streambank along State Route 20 near Post Mile (PM) 40.67. To stabilize the streambank, 470 cubic yards of ¼ ton rock slope protection (RSP) and RSP fabric will be placed along 120 feet of the Grizzly Creek streambank. RSP will be placed in the channel from the top of the bank/roadway level. An excavator located in the channel will place the RSP along the bank. The RSP will be keyed in 3 feet at the bottom of the slope. Approximately 65 cubic yards of soil will be excavated in order to key in the RSP. The excavated soil will be disposed of at the contractor's disposal site, which is located approximately 5 miles west of this location. The culvert at PM 40.67 will not be modified. The culvert will drain over the top of the newly placed RSP. Two to three small willow trees (Salix sp.,) will be removed in order to place the RSP. These willows are growing above the ordinary high water mark of Grizzly Creek. Willow cuttings will be incorporated into the RSP in order to offset this loss of willow trees. Cuttings will be collected from sources within the vicinity of the work area. Temporarily impacted areas of the Grizzly Creek streambank will be restored to pre-project conditions upon project completion. Original contours will be restored once the project is complete. Revegetation of temporarily impacted areas of the Grizzly Creek streambank will be conducted through permanent erosion control. Spanish clover (Lotus purshianus), thingrass (Argostis pallens), bottle-brush squirreltail (elymus elymoides), Idahoe fescue (Festuca idahoensis), meadow barley (Hordeum brachyantherum), California melic (Melica california), and pine bluegrass (Poasecunda) will be used for permanent erosion control. In addition, Caltrans will debit 0.070 acres of riparian vegetation credits at the Caltrans Beach Lake Mitigation Bank to offset permanent and temporary impact associated with this work.

5 documents in project