Flood Control Zone 4
Zone 4 at a Glance
Communities served: Portions of Hayward, and communities of Mohrland and Russell City
Area in acres = 2,960
Zones 3A and 4 combined
Total miles of natural creek: 21
Total miles of earth channel: 20
Total miles of concrete channel: 5
Total miles of underground pipe: 43
Zone 4 Hydrology
Situated on the shoreline of San Francisco Bay, this zone is at the western edge of a large alluvial fan created over time by streams draining from the East Bay hills. The alluvial fan, or plain, is made up of sand, silt, and mud deposited by water flowing to the Bay.
Zone 4 Major Projects
Zone-Wide Planning
District engineers began updating the flood control master plan for Zone 4 in 2005. The master plan looks at the entire zone and complete flood control systems rather than individual sections.
Using the latest engineering software and Geographical Information Systems (GIS) capabilities, engineers evaluated the zone’s existing flood control facilities. Their study yielded a list of additional needs for long-term flood control improvement in the zone, including improvements to Line A.
Line A – A Former Bottleneck
In response to the master plan, design began on a channel embankment repair and capacity improvement for a stretch of Line A, an earthen channel that runs through the neighborhood of Russell City to the Bay. Line A has been a bottleneck for stormwater flow. Construction has been divided into two phases scheduled for fiscal year 2007 and 2008: Phase 1) a $1.3 million project between the Union Pacific Railroad (UPRR) and Cabot Boulevard, and Phase 2) a $600,000 project between Cabot Boulevard and Line E. The project will use natural materials to create the most environmentally sensitive result possible.
For more information about the history of projects undertaken in Zone 4, please view the District’s Annual Reports.