Lohr Napa River Bank Repair, (Lake or Streambed Alteration Agreement No. EPIMS-NAP-57553-R3)

The California Department of Fish and Wildlife has executed Lake and Streambed Alteration Agreement EPIMS Notification No. EPIMS-NAP-57553-R3, pursuant to Section 1602 of the Fish and Game Code, to Streamline Engineering as represented by Eric Austensen. The Project is limited to stabilizing approximately 100 feet of the Napa River bank adjacent to a water storage pond. The Project area includes a ten-foot head cut occurring where a roadside ditch draining from Pratte Avenue joins the river. The Project will construct a live vegetated rock revetment to achieve the primary purpose of preventing loss of the pond via erosion of the embankment and to stabilize the head cut. The vegetated rock revetment will be constructed by placing large (1 to 3-ton) boulders and filling the rock interstices with a growing medium consisting of gravel and 4-inch to 9-inch rock. Rock will be transported to the revetment area using a wheeled front-end loader along an access route of dry stream bed, with an entry point approximately 580 feet downstream from the revetment area. Placed rock will not extend into the channel beyond the previous position of the eroded bank. One tracked excavator will be used below top of bank for the construction of the revetment and stored above top of bank when not in use. The revetment will be planted with approximately 380 willow (Salix spp.) cuttings. An existing fallen concrete headwall will be hauled offsite and disposed of in accordance with local and state regulations. The Project will result in 0.063 acres (2,700 square feet) and 100 linear feet of permanent impacts to stream and riparian habitat resulting from the rock revetment, and 0.164 acres (7,140 square feet) and 185 linear feet of temporary impacts to stream and riparian habitat resulting from the revetment worksite and equipment access point downstream. The 580-foot-long temporary access route will be used by the front-end loader and up to three round-trip passes of the excavator. The project will remove six riparian trees including three oak trees (Quercus ssp.) with diameter at breast height (DBH) of 10 inches each, one four-inch DBH oak tree, one 30-inch DBH Eucalyptus tree (Eucalyptus spp.), and one 12-inch DBH Eucalyptus tree.