Ackerson Meadow Restoration
Ackerson Meadow is the largest mid-elevation meadow in Yosemite National Park. The meadow is a vital wildlife corridor and habitat for endangered species such as the great grey owl and little willow flycatcher. Ackerson Meadow is facing significant challenges as a result of a century of landscape manipulation such as domestic water diversion, farming, ranching, and logging. These manipulations have created a large erosion gully network, impacting 90 acres of wetlands in the meadow and is eroding an additional 100 acres of remaining wetlands.
The Ackerson Meadow Restoration Project was initiated through collaboration between Yosemite National Park, Stanislaus National Forest, American Rivers, and Yosemite Conservancy.
Our work in the highly sensitive habitat involved a complex process filling the gully system and restoring hydrologic function to the 230-acre meadow. Ultimately, raising the streambed and water table will help reconnect the meadow floodplain, while slowing and spreading water flow across the meadow. Increasing groundwater recharge and storage improves flood protection downstream and overall increases water quality, storage, carbon sequestration, and wildlife habitat.
Hanford produced and installed approximately 100,000 cubic yards of native soil in the erosion gullies. About 50% of this fill material was mixed with site-sourced wildfire impacted tree wood chips. We installed a robust rock weir grade control structure at the downstream end to prevent further damage to the restored meadow floodplain from the existing road and related infrastructure. Hanford salvaged and installed wetland grasses and willows throughout the project area. Hanford will return in spring of 2024 to install container plants to complete the restoration project.
