Work that put the equivalent of half a million dump trucks' worth of slushy soil on the old Hamilton Airfield has been finished, marking a milestone in the massive wetlands restoration project in Novato.
"It was completed earlier this month," said Tom Gandesbery, project manager for the state Coastal Conservancy. And the work is already paying environmental dividends.
"We are seeing more birds come to the area," Gandesbery said.
Ruddy ducks, hawks and egrets are visiting the area, but work on the $104 million project is not quite done. About 250 acres of the 700-acre site still needs to be contoured to create pools, and other areas will be planted with native vegetation. A 2.5-mile Bay Trail segment that runs along the perimeter of the airfield is also planned. Most critically, the levee holding back San Pablo Bay water will be breached. That will allow bay water to rush back into the area, helping return hundreds of acres of vital, ecologically rich wetlands that were choked to death more than a century ago as land was diked for farming.
That could occur as soon as October 2012.
"The big thing will be the breaching," said Dick Wayman, conservancy spokesman. "That will allow the tidal bay action to return."
On Thursday the conservancy board approved $4 million to pay for the final work that completed the sediment work on the runway. The state Wildlife Conservation Board will reimburse the conservancy.
The airfield has received about 6 million cubic yards of sediment since material began arriving at the site in 2008, covering it in 4 to 7 feet of mud. The majority of the dredged material came from the Port of Oakland — with a smaller amount from other bay ports — through a system of temporary barges and pipes that sent the slurry some seven miles to Hamilton. That system is now being dismantled.
The military decommissioned the base in 1974 and ballfields, a polo field and even a skate park were bandied about as potential uses for the airfield over the years. But a cadre of environmental groups and state agencies, led by the Coastal Conservancy, were determined to return the area to what it used to be.
Planners studied old maps from the 1800s, historic photos and dated drawings for a better understanding of what was at the airfield before the landscape was changed.
In the North Bay, up until the mid-19th century, there were some 55,000 acres of wetlands, providing ideal conditions for migrating waterfowl, a nursery for a variety of fish species and an incubator for plants. A potent mix of wetlands — tidal marshes, tidal flats, vernal pools, streams and creeks — provided optimal conditions for a myriad of plant and animal life.
As people settled nearby, they saw the areas of shallow water as locales where water could be diked and drained and the area reclaimed for agriculture and housing.
As the wetlands dried up, so did the number of species. Legions of fish, California clapper rail, brown pelicans, California black rail, salt marsh harvest mice, red-legged frogs, snowy egrets and great blue herons were lost, and today many are listed as endangered.
When the land was diked, it not only dried but constricted as well. The sediments from Oakland were needed to raise the ground surface of the site to a level near sea level.
"I heard it is done, it's spectacular news," said Barbara Salzman, president of Marin Audubon. "I can't wait to see the tidal action come in once the levee is breached."

(http://www.marinij.com/marinnews/ci_17647463?IADID=Search-www.marinij.com-www.marinij.com)

I was very interested by this story because for a while in the immediate past, I would see a lot of trucks driving towards the marshes but I could never see what they were actually doing, until one day I walked up Ammo Hill, looked down and saw new marsh I had never seen before. I'm also very interested in Hamilton's history as an Air Force Base during WWII, and to me, that's all the history of Hamilton was. I never thought about what it looked like here before the Air Force base, but I'm glad to see that we made efforts/ are still making efforts to restore what it used to be. These wetlands will be very beneficial to this areas biodiversity, and will bring back marine species that live in wetlands, as well as many other animals.