Alameda County Flood Control and Water Conservation District
Flap Gate and Outfall Structure Rehabilitation at Eden Landing Pump Station (Zone 3A, Line A), Hayward, Alameda County, California.
NOE - Notice of Exemption
The Alameda County Flood Control and Water Conservation District (District) owns and maintains the Eden Landing Pump Station. Eden Landing Pump Station requires maintenance repair and replacement of the existing flap gate and outfall structure as part of the maintenance process. This would also require rehabilitating and repairing an existing concrete outfall structure that is connected to the pump station outfall. Spalled concrete on existing concrete headwall and wingwalls will be removed and patched with new concrete. The new concrete headwall and wingwalls will be constructed in front of the existing headwall and wingwalls. The existing concrete apron will not be disturbed. Work will include removal and replacement of the existing 48” flap gate with a new flap gate. Work on the outfall structure and flap gates will require a temporary gravel bag cofferdam installed within a tidal zone. Most of the cofferdam will be on an existing concrete apron but portions may need to be on a rock slope protection area of the flood control channel. A flow-through plug may need to be utilized to keep the pump station discharge operational during the work. Work will be phased to take place during the summer months to minimize any impacts.