Birders Get Back Stage Pass to Hamilton Wetlands Restoration Project

This month, 33 Bay Area bird watching enthusiasts were given special access past the security gates in order to get a behind-the-scenes tour of the wetlands restoration project at Hamilton Field.

The tour was arranged by Hamilton resident Harvey Abernathey as part of the annual San Francisco Bay Flyway Festival (Feb. 10-12), a bird watching event founded in 1996 to offer access to areas of the San Francisco bay, not normally open to the public.

Abernathey has been attending the Mare Island-based festival for the past five years and after months of negotiation with various agencies got the green light to include Hamilton in the festival’s program of regional events.

Timing and luck also played a part in securing the tour. Abernathey said that until recently the area was still a hard-hat zone with heavy equipment on-site and strictly off-limits to the public.

Eric Jolliffe, an environmental planner with the US Army Corps of Engineers and Brenda Goeden, a sediment manager with the Bay Conservation and Development Commission served as guides to the project.

The tour began with a hike up a public trail that plateaus and serves as a lookout point.  Many were surprised to find out that they were standing on a buried water tower that services the Hamilton community.

From that vantage point, Jolliffe was able to point out the outline of the former Air Force runway that has been covered with recycled dredge material from the Port of Oakland.

Staging ponds are also in place, some partially filled with rainwater and water from when the dredge material was piped in from offshore barges in a mix that was 80 percent water to 20 percent dredge.

“5.6 million cubic yards of dredge material will eventually cover the project – and the bulk of it’s going to be from tidal action,” Goeden said.

“We want this to function as a seasonal wetlands and shorebirds habitat,” added Jolliffe.

For the rest of the tour, the group was allowed to caravan directly on to the off-limits levee to get an overview of the project’s status and see some of the birds that have already moved-in to their under-construction digs.

The outer levee is essentially serving as a construction road and runs parallels to and about a quarter-mile across from the city’s public levee that borders Hamilton Field homes.  Access to the outer levee is gated and is patrolled by on-site security.

The road is being used by several government agencies and separates the Hamilton Field wetlands project from an unrelated flood control project on the North Antenna Field.

The tour group was able to walk out to the eastern-most portion of the levee that is essentially the last barrier to the SF Bay.

Jolliffe pointed out that once that levee is breached-- along with the first two adjoining ponds-- water will ebb and flow with the tides, gradually filling the other multi-level ponds.

The ponds are built with special hydrology equipment that will allow the engineers to control how much water enters the area.

Jolliffe calls the project one big experiment and says it’s one of the largest wetlands restorations attempted with the entire process completing in five to ten years, what would normally take 75 years, if nature was allowed to take its course.

As part of the experiment, vegetation suitable for the seasonal wetland will be planted in test polygons. Both vegetation that is desirable and vegetation that is undesirable will be planted to make sure that the salinity of the water is correct. 

“If any of the unwanted plants start to thrive we will adjust the salinity and the length of time that the plants are underwater with the hydrology,” Jolliffe said.

The tour group included a mix of experienced birders and some Hamilton residents who wanted to see the progress of a project that is visible from their own backyards.

Looking out over the ponds with the sun shining, birds in the foreground and views of Hamilton’s airtower in the background, Novato resident Tom Keena called the project “magnificent.”

Mute swans, cinnamon teals, canvasback ducks, white throated swifts, blue herons, and least sandpipers were some of the species that newbies to birding could check off their list.

But even the experienced were thrilled to find a burrowing owl sitting only ten feet off the eastern levee trail. The owl stayed and allowed everyone to get a good look or photo.

Because of the enthusiasm of the guides, participants and festival organizers, Abernathey said that he hopes to do the event again next year and be able to track the changes in the numbers and types of birds on the developing wetlands.

For Abernathey, like the rest of the group, it’s all about the birds -- spotting something that’s unique or seeing it up close and personal – and on that level he said the outing was a complete success. 

“That burrowing owl was the highlight of the trip,” Abernathey said.