Phase 2 and 3 of Ardenwood Creek (Zone 5, Line P) flood Control Channel Improvement Project, California

Phase 2 and 3 of Ardenwood Creek (Zone 5, Line P) flood Control Channel Improvement Project, California

The purpose of the project is to improve hydraulic conveyance of the channel to meet Federal Emergency Management Agency (FEMA) flood protection standards. The project would be constructed in three phases and Phase 1 has already been completed. Phase 2 would restorepositive drainage to the earth channel by removing sediment from an approximately 2,600 LF section of the Ardenwood Creek flood control channel from 0.4 mile downstream of Paseo Padre Parkway to the Patterson Ranch Road crossing. Phase 3 would remove deteriorating culverts further downstream at Patterson Ranch Road and the adjacent Tuibun Trail, the Chochenyo trail crossing, and the Demonstration Urban Stormwater Treatment (D.U.S.T.) Marsh trail crossing and replace them with clear span prefabricated bridges supported by abutments placed beyond the top of bank. The bridge foundations would be protected from scour by rock placed on the creek bank. One of the Project objectives is to reduce the slow spread of the cattail marsh and encourage more desirable seasonal wetlands occupied by pickleweed and other desirable native plant species. The Project would accomplish this by helping to manage the high groundwater table through the deepened and positively drained Ardenwood Creek channel invert, and by removing cattails in the overbank area used for truck haulage of channel spoil. The replacement of the culverts, which restrict drainage, by clear span bridges, would also be beneficial by improving passage of flood flows, and creating new jurisdictional wetland and open water areas. Culvert to clear span bridge conversion would also help control the unwanted spread of cattails in wet and ponded areas. Phase 2 is planned for construction in the summer or fall of 2023, pending receipt of all regulatory permits. Phase 3 is planned for construction in 2024 or later, pending funding availability and separate permit acquisition. Construction may extend over two or more seasons depending on regulatory requirements and seasonal work windows.The purpose of the project is to improve hydraulic conveyance of the channel to meet Federal Emergency Management Agency (FEMA) flood protection standards. The project would be constructed in three phases and Phase 1 has already been completed. Phase 2 would restorepositive drainage to the earth channel by removing sediment from an approximately 2,600 LF section of the Ardenwood Creek flood control channel from 0.4 mile downstream of Paseo Padre Parkway to the Patterson Ranch Road crossing. Phase 3 would remove deteriorating culverts further downstream at Patterson Ranch Road and the adjacent Tuibun Trail, the Chochenyo trail crossing, and the Demonstration Urban Stormwater Treatment (D.U.S.T.) Marsh trail crossing and replace them with clear span prefabricated bridges supported by abutments placed beyond the top of bank. The bridge foundations would be protected from scour by rock placed on the creek bank. One of the Project objectives is to reduce the slow spread of the cattail marsh and encourage more desirable seasonal wetlands occupied by pickleweed and other desirable native plant species. The Project would accomplish this by helping to manage the high groundwater table through the deepened and positively drained Ardenwood Creek channel invert, and by removing cattails in the overbank area used for truck haulage of channel spoil. The replacement of the culverts, which restrict drainage, by clear span bridges, would also be beneficial by improving passage of flood flows, and creating new jurisdictional wetland and open water areas. Culvert to clear span bridge conversion would also help control the unwanted spread of cattails in wet and ponded areas. Phase 2 is planned for construction in the summer or fall of 2023, pending receipt of all regulatory permits. Phase 3 is planned for construction in 2024 or later, pending funding availability and separate permit acquisition. Construction may extend over two or more seasons depending on regulatory requirements and seasonal work windows.

Fremont

Alameda

Northern California

Alameda