Yosemite National Park and the Stanislaus National Forest are seeking commentary from the public on their plan to restore wetlands in the Ackerson Meadow, which they said have been drained as a result of a century of domestic water diversion.
The plans include a complete fill of the gullies developed over the last century by ranchers and agriculturalists who utilized water flow, or the the installation of manmade beaver dams to partially restore the wetlands.
Ackerson Meadow and South Ackerson Meadow, which were donated to Yosemite National Park in 2016, make up the largest mid-elevation meadow complex in the park. The meadow complex spans into the U.S. Forest Service lands of the Stanislaus National Forest and are considered important habitats for at-risk wildlife species, such as the endangered great grey owl and little willow flycatcher.
What they have referred to as a "large erosion gully network" is measured at maximum depths of 14 feet and 100 feet wide. A news release said the gully network is draining 90 acres of former wetlands within the meadow complex and threatening an additional 100 acres of wet meadow.
"The gully network is a result of over a century of landscape manipulation including domestic water diversion, farming, ranching, and timber harvest," the National Park Service said in a release.
The restoration project has been hailed by conservation and preservation organizations, such as the Central Sierra Environmental Resource Center in Twain Harte.
"If no restoration project moves forward, Ackerson Meadow wetland areas will continue to dry, leaving some rare wildlife that rely on them with little to no habitat," Sara Husby, program director at CSERC, said. "Our center is excited to see that the Stanislaus National Forest and Yosemite National Park are taking the necessary steps to restore such an important and sensitive area."
The goals of the restoration include protecting the wetlands and establishing natural hydrologic conditions. The plan is expected to establish high water tables, an increased proportion of wetland plants and a hospitable habitat for wildlife. Invasive species would be removed.
The plan also includes functional grazing allotments on Forest Service-managed lands. Grazing is not allowed in the park.
Husby said CSERC has been involved in the public planning process since it began last year and plans to review the documents and provide comments in the coming weeks.
The acquisition of the meadow by Yosemite National Park has long been the bane of local ranchers who vehemently criticized it as impinging on Tuolumne County's long history of cattle grazing.
In December 2015, Shaun Crook was president of the Tuolumne County Farm Bureau and spoke against the transfer on behalf of his organization to the county Board of Supervisors at a public meeting.
“For over 100 years, the land has been managed through grazing and logging,” he said at the time. “Proper forest management has allowed the survival of the (Great Gray) Owl and meadow. … I strongly fear we will lose those qualities if it’s turned over to the national park.”
The Ackerson Meadow was privately held land dating back to 1857. It was primarily used for ranching and agriculture for more than 150 years, which led to the installation of drainage ditches and vegetation alteration due to grazing by sheep and cattle.
"These alterations culminated in extensive soil erosion, gully formation, and a lowered water table at Ackerson Meadow complex," the park service said in a release.
In September 2016, 400 acres of critical wetlands and meadow habitat on the park's western boundary known as Ackerson Meadow was donated to the park through a cooperative effort between the Trust for Public Land, Yosemite Conservancy, and the National Park Service.
The Trust for Public Land purchased Ackerson Meadow from private owners for $2.3 million.
Three options for projects to restore the meadow complex were developed by the park service through public input sessions last year. Its preferred option would be to completely fill the erosion gullies to the level of the meadow in order to "restore original topography, hydrology, and vegetation."
Fill material would be a combination of soil from upland hills, wood chips and biochar, a charcoal that is used as a mix in soils. The project would require 151,000 cubic yards of filler.
"This alternative will maximize the acres of protected and restored existing and former wetlands," the park service said on the restoration page.
Another option proposed was the installation of 350 hand-built structures in the gullies to deposit sediment and redirect water flow. The project would require the installation of beaver dam analogs, or man-made structures that replicate beaver dams, which would create a stair-step sequence of ponds about 4 feet deep and over the channels.
The project would not require fill or heavy equipment, but would not "fully restore the gullies to natural meadow topography, rather it would enhance the wetland and floodplains within the gully network and eventually form an inset floodplain."
The park service said the introduction of beavers to the meadow was considered infeasible at this time.
The last option would be a hybrid of the two plans, filling in deeper portions of the gullies and installing the BDAs where the gullies were less than 3 to 5 feet deep.
Annual long-term maintenance is required for both options involving the BDAs.
The project area for the alternatives encompasses 1,210 acres and 230 acres of the Ackerson Meadow complex.
Comments on the environmental assessment can be submitted through July 8 online at https://www.nps.gov/yose/getinvolved/ackersonmeadow.htm.
Contact Giuseppe Ricapito at firstname.lastname@example.org or (209) 588-4526.