Drainage Restoration: Upper Jordan Gulch (East Branch)

Drainage Restoration: Upper Jordan Gulch (East Branch)

Existing poorly designed waterbars and earthen ditches in and adjacent to Spring Road would be replaced with properly designed earthen ditches and waterbars, and the gravel roadbed would be recontoured to slope northward toward the new ditch (using mechanized equipment). Two undersized (4-inch and 12-inch) metal pipe culverts that convey runoff beneath the road to the drainage would be replaced with an adequately sized (24-inch) pipe culvert. All road runoff from the culvert would be directed to a new compacted earth inlet basin, from which it would enter a new subsurface, 300-foot long, 18-inch diameter metal pipe culvert to be installed west of the channel. (Trenching with a backhoe to allow the installation of the northernmost 225 feet of the pipe would occur within a fenced, 20-foot wide corridor along the pipe alignment; the remaining approximately 75 feet of the pipe near the drainage channel would be installed above-ground, with no mechanized trenching required.) The proposed pipe alignment would avoid all mature trees, but saplings and shrubs would be removed. The resulting vegetation loss would be temporary, and it is expacted that native species would soon re-colonize the site. Flows from the pipe would be discharged to a rock energy dissipator within the channel. As many as four wooden check dams would be installed within the natural drainage channel using hand tools. Erosion from seepage from the perched aquifer would be controlled by the installation of a 4-inch, perforated plastic subsurface drain line that would collect subsurface flows and direct them to the natural drainage. Areas of Disturbed soils will be seeded with barley and mulched with straw to prevent surface erosion.

Santa Cruz

Santa Cruz