A project taking place some 20 miles south of the Presidio will result in new life for dried-up wetlands in the national park, as part of a unique arrangement with San Francisco International Airport.
The old wetlands — once primary water sources for American Indians and early European settlers — are to be restored under a $7.5 million plan funded by SFO under the 1972 Clean Water Act.
The airport is set to embark on a runway-improvement program to strengthen land near its airstrips, which calls for 3.7 acres of San Francisco Bay wetlands to be replaced with landfill. Under the water act, replacing Bay coastland requires adding back twice as much wetlands somewhere else in the region.
The San Francisco Airport Commission agreed Tuesday to spend $7.5 million restoring three old creeks in the Presidio. One wetlands area is near Mountain Lake, and the other two are in the northeast area of the national park.
The former wetlands played an integral role in allowing Spanish settlers to create a fort in the Presidio, said Terri Thomas, an ecologist with the Presidio Trust.
The project will restore 7.4 acres of wetlands and help set up a continuous stream of water, running from the Presidio and underneath Doyle Drive, which is being rebuilt, and into the salt marshes of Crissy Field, Thomas said. By restoring the ecology, the project will replace piped water with natural streams, a change that should encourage once-native animals to return, Thomas said.
Typically, restoration projects take place near the area where landfill is being added to the Bay, said Bruce Wolfe of the San Francisco Bay Regional Water Quality Control Board, a state group that regulates shoreline development. When no suitable sites could be located near the airport — a spate of restoration projects have recently been finished at the hub — the Presidio was chosen as an ideal alternative, Wolfe said.
The wetlands at the airport are located between two landing strips, making them a less than ideal habitat for many creatures, Wolfe said. The airport has already taken efforts to keep the areas free of birds, which can hamper flights.
Under a mandate from the Federal Aviation Administration, SFO must fortify emergency landing areas near its runways, and the landfill project will help accomplish that goal. Work on that project is scheduled to start this summer. Restoration work in the Presidio also is slated to begin later this year.
SFO is funding the Presidio wetlands project after preparing to remove Bay wetlands near the airport. The Clean Water Act requires the replacement of displaced wetlands.
3.7 acres Amount of Bay landfill being added to SFO
7.4 acres Wetlands being restored in the Presidio
$7.5M Cost of wetlands restoration project
Areas in the Presidio being restored:
Mountain Lake East Arm