SCH Number 2015042009

Project Info

Title

Site 18A Culvert Replacement and Fish Passage Enhancement Project

Description

CDFW has executed lake and streambed alteration agreement no 1600-2015-0079-R2, pursuant to section 1602 of the fish and game code to the project applicant, Sacramento Area Flood Control Agency. The proposed project will include the following activities: Culvert Replacement: A new, larger cross-sectional area, steel plate or concrete arch culvert (approximately 10 to 12-ft wide opening) will connect the Site 18A flood basin more directly and openly to NEMDC/Steelhead Creek, and allow for more positive drainage and fish outmigration into NEMDC/Steelhead Creek and farther downstream to the Sacramento River. The existing culvert will be removed and the new arched culvert would be installed through the bike trail berm in the northwest corner of Site 18A. Swale Modifications: Fish rearing habitat will be enhanced and fish stranding reduced by improving connectivity between NEMDC/Steelhead Creek and the Site 18A floodplain habitats. Existing interior drainage swales would be graded to provide more relief in the micro topography to further enhance outflow gradients between the creek and the basin's vegetated floodplain habitat. Habitat Enhancement: To improve rearing habitat and refugia in the basin floodplain, additional seasonal wetlands plants and riparian scrub would be planted within the Site 18A basin. Enhancement efforts will provide cover and increase habitat variability. Growth rates and canopy cover of existing and proposed new riparian vegetation would be increased by deep-ripping the underlying root-restricting layer (Riverbank Formation) that has suppressed growth rates of trees planted since 1996. Denser, higher quality floodplain habitat and cover for fish will be created at the northwest corner of the Site 18A basin to concentrate and attract fish to the culvert drainage exit.

5 documents in project