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Wawona Meadow Ecological Restoration Phase II
Yosemite National Park » Wawona Meadow Ecological Restoration Phase II » Document List
The primary goal of this project is to ecologically restore the hydrology, native plant communities, and wildlife habitat to the Wawona Meadow.
Ditches that were constructed in the Wawona Meadow in 1936 have altered its hydrology by disrupting both surface and subsurface flow, lowering groundwater levels, drying out adjacent areas, and altering plant communities. The ditch on the south side of the meadow extends for one mile and was reinforced with 22 buried concrete weirs. Fourteen of those weirs are more than 50% exposed. Most of them are located in the 982-feet length of the ditch that has eroded to 10 feet deep. Water flows through the ditch for most of the year, draining the groundwater from the meadow. This is evidenced by the dominance of upland (rather than wetland) and non-native plants adjacent to the gullied sections of the ditch. The rest of the ditch varies: Some parts have slow moving water (1 to 3 feet deep) and other parts are heavily vegetated with no water flow. The ditch on the north side of the meadow is mostly shallow and has less impact on hydrology. Monitoring of hydrology, plant communities, and wildlife would help direct restoration actions.
This project will implement the following actions:
• Remove concrete weirs above ground level and recycle out of the park.
• Fill sections of the ditch with 4,000 cubic yards of native fill.
• Place "plugs" or grade-control structures to re-contour the area and discourage concentrated water flow.
• In shallower sections of the ditch, pull back the remaining soil berm.
• Salvage plants and topsoil prior to restoration disturbance.
• Collect native seeds from adjacent areas.
• Re-vegetate newly restored areas by replacing topsoil and salvaged plants, seeding, and planting willow.
• Place five wayside exhibits around the meadow loop describing meadow ecology, historic events, and the restoration process.
Permits: 401/404 permits from Army Corps of Engineers and California Regional Water Quality Resources Board.
Equipment: Excavator, dump truck, bobcat, or backhoe would access the project from Wawona Loop road. The access points would be cleared by cultural and natural resource staff. All equipment would be inspected for weed seeds.
Staging: Wawona maintenance yard or parking area for the Meadow Loop Trail.
Timing: Late August to October, when groundwater levels are low.
Project duration: Depending on funding, the project may be implemented in stages and completed by 2010 or 2012.