Elkhorn Slough: the $4.5M project to preserve mud
Underground wall designed to slow erosion in the tidal estuary
John Sammon
Santa Cruz Sentinel
05/18/2011
At Elkhorn Slough, it's all about mud, preserving mud.
Before a gathering of 50 wildlife officials, local residents and directors of the Elkhorn Slough Reserve on Wednesday, Bryan Largay, director of tidal wetlands for Elkhorn Slough National Estuarine Research Reserve, touted the successful completion of the "sill," a $4.5 million project designed to slow erosion in the tidal estuary.
"Elkhorn Slough is an amazing and beautiful place," Largay said. "Mud is what sustains the basic building block to support wildlife in the area. For the first time in 60 years, we have a project that will support a more sustainable marsh."
A newly constructed underwater retaining wall, the sill is 200 feet wide, 15 feet high, and 5 feet underwater.
A steel wall surrounded by rock, the sill weighs 3 million pounds and was installed in interlocking parts. It is located near Union Pacific railroad tracks at the confluence of Parson and Elkhorn sloughs, twin channels leading from the sea that feed more than 3,000 acres of marsh and tidelands, habitat for innumerable birds, fish, crustaceans, otters, seals and other animals.
Elkhorn Slough officials say they can already see the benefits of the project. Plant, bird, and other animal life have adapted well to the project including as many as five otter moms and pups resting in the area by the sill. Last month, biologists witnessed an otter birth born very near the construction site. And harbor seals with pups are use the area extensively.
The project is anticipated to restore an additional seven acres of tidal marsh around the perimeter of the Parsons Slough Complex.
About 3 miles from Moss Landing Harbor, the area of the sill remains closed to boaters, but the area is visible from the reserve center's overlook.
"The majority of the funding is from the American Recovery & Reinvestment Act," said Lorili Toth, director of development and communications for the Elkhorn Slough Foundation.
Largay said the sill is designed to ease in-and-out tidal erosion from the sea, which is eating away at the banks of the slough and the mud and sediment deposits vital for its health.
In 1947, a direct channel was cut through sand dunes to allow a permanent entrance to the Moss Landing Harbor, exposing marshy areas to greater tidal surge.
The project also made improvements to public access at the slough's Kirby Park including a new boat dock and repair of a parking lot at the site.
Mark Pastick, owner of Kayak Connection in Santa Cruz and Moss Landing, said he's pleased about the sill and its erosion-fighting.
"That been a concern for decades," he said. "I'm also impressed with the Kirby Park upgrades."
The successful completion of the project included securing 14 permits from state and federal agencies and the collaborative efforts of the National Oceanic & Atmospheric Administration, California Department of Fish and Game, Elkhorn Slough National Estuarine Research Reserve, U.S. Fish & Wildlife, David & Lucile Packard Foundation, California Coastal Commission, California State Coastal Conservancy, U.S. Environmental Protection Agency, Union Pacific Railroad, California Regional Water Quality Control Board and the Monterey County Planning Department.
Duck's Unlimited, an international nonprofit involved in conservation of wetlands, oversaw the engineering contracts for the project. URS Corp. based in Oakland did the project design.
Mark Silberstein, executive director of the Elkhorn Slough Foundation, called the project, "one small step for mud." He said the project involved numerous planning meetings with members of the public, scientists, engineers and groups concerned about the health of the slough.
