SACRAMENTO, Calif. – The U.S. Army Corps of Engineers Sacramento District beat a major deadline on the Napa Railroad Relocation Project when it removed the second of two cofferdams from the Napa River Dec. 8, keeping flood risk reduction work for the city of Napa, Calif., on schedule.
The cofferdams, enclosures created by pile driving long sheets of metal into the ground, were necessary to maintain a dry work area to build two bridge piers in the middle of the Napa River. The piers will support spans for one of six new railroad bridges across the river, including five that are replacing lower bridges that needed to be removed for the river to safely pass more water.
With the rainy season approaching and a permit to work within the Napa River set to expire Dec. 15, completing the bridge piers and removing the cofferdams before that day was vital.
"Completion of this in-water work allows construction to continue during the winter on the bridge span over the river,” Corps project manager Bert Brown said. “If this in-water work had not been completed before Dec. 15, this component would have been delayed until June 2011.”
Funded largely by the American Recovery and Reinvestment Act of 2009, the $65 million Napa Railroad Relocation Project, part of the larger Napa River-Napa Creek Flood Protection Project, is scheduled to be completed in 2012.
The Napa River-Napa Creek Flood Protection Project is a partnership between the Corps, the city of Napa and the Napa Flood Control and Water Conservation District designed to help reduce the risk of flooding in the Napa community.
Work on the Napa Creek phase of the project is expected to begin in February. The $14.8 million stimulus project, awarded to Proven Management Inc., will install two large diversion culverts and improve river bank protection along Napa Creek running from its confluence with the Napa River about 3,500 feet to Jefferson Street. The project will also replace the Behrens Street Bridge.
The U.S. Army Corps of Engineers Sacramento District provides flood risk reduction, navigation, watershed planning and ecosystem services in parts of eight western states, including California, Nevada, Utah, Arizona, Colorado, Idaho, Oregon and Wyoming.