Port dredging to benefit Bair Island
The mud sucked up from an upcoming dredging project at the Port of Redwood City will be delivered to inner-Bair Island to restore hundreds of acres of the area’s tidal marshes. The island, right next to the Whipple Road exit off Highway 101, is currently mostly brown near its center and plays home to endangered birds and mice, among other species unhappy with their homes. “What people will see in the first few years is that brown island turning green,” said David Lewis, executive director of Save the Bay, a group working with the port and the U.S. Fish and Wildlife Service as part of Save the Bay’s Bair Island Restoration Project. The project is being done partly because 90 percent of the San Francisco Bay’s historic tidal marshes are now gone, Lewis said. The dredging process essentially involves applying a giant vacuum cleaner to the bottom of the shallowest part of the channel. The regular process gets rid of about a foot of mud so that incoming ships can reach the port — but usually the mud is dumped on an out-of-state site by the U.S. Government. The mud from the upcoming project, however, appears destined for greater causes. The clean material will help raise the area in the center of the island and create tidal marshes. The raised elevation, coupled with the opening of a levee that will allow water and sediment to flow through from the Bay to the island, will result in a much better living environment. The restored marshes would also soak up water better, serving as natural flood control. Inner Bair Island is subsided because it was used as a salt pond and allowed to dry out, Lewis said. If the island isn’t raised soon, a lake will form, he added. “The elevation of Bair Island is significantly below sea level so the level of the island needs to be raised in order to restore the marsh more quickly,” said Mike Giari, Port of Redwood City executive director. The dredging, preliminarily scheduled for September, will be the port’s first in two years and the first time it has done anything with the mud other than disposing of it. About 200,000 cubic yards of mud will be removed to increase the channel’s shallowest waters from 29 feet deep to 30 feet. The project should cost $2.5 million to $3 million and will be paid for by the federal government. Typically the mud from the port’s dredging is taken to a site in Nevada by the U.S. Army Corps of Engineers. This time, they’ll take the mud sucked up by a hydraulic dredge, mix it with water and send it through a pipeline that connects to Bair Island. The project is a win-win for both parties because it’s a shorter trip — meaning cheaper costs. This particular mud also seems to be a good fit for the marshes that will thrive on water flowing in from the Bay. “What material could be more appropriate for this marsh restoration than Bay mud?” Giari said. The restoration project has been being planned for the past three years and should begin in the coming months. Project volunteers will also enhance the island’s parking, improve walking trails and build a bridge from the outskirts to a trail at the center of the island. Plants will also begin to grow there as groups of Save the Bay volunteers take canoes out to plant seeds on the island. The process should also reduce the heavy numbers of mosquitoes currently in the area, Lewis said. One of the species that will benefit most from this project is the California clapper rail, a grayish brown chicken-sized bird with a long, downward curving bill. There are only a few hundred of these left, Lewis said. The bird has lost most of its Bay Area marsh habitat due to land development and shoreline fill. Another animal happy to hear about the restoration is the salt marsh harvest mouse, a tiny brown critter. Recent development in its area has gotten so bad that it now has to worry about domestic cats as predators, Lewis said. |
©2007 Daily Journal
