The Nature Conservancy in South Dakota is working to conserve a small but unique spring-fed wetland at itsWhitney Preserve located near Hot Springs that is at risk due to erosion caused by the 2007 Alabaugh Canyon wildfire.
A contractor is using cottonwood trees killed in the wildfire to install step-like dams that resemble a series of waterfalls to reduce the energy of water as it flows through the bottom of Alabaugh Canyon.
Earthorizons, an excavation contractor from Black Hawk, S.D., started working on the project this week after the Conservancy consulted with U.S. Forest Service hydrologists to determine how the wetland could be conserved.
The project, which is expected to be completed by the end of March, is designed to help protect the wetland from further erosion and prevent a water channel that has been developing and deepening due to the 2007 wildfire.
The fire denuded the walls of Alabaugh Canyon of native vegetation and leaf litter, so after a rain event there is now little to impede the flow of water as it runs down the canyon walls and then flows through the wetland.
The wetland is normally fed by a spring known as Cool Springs that provides continuous water flow, allowing water to soak into the surrounding soil.
The wetland serves as a buffer for droughts and helps the deciduous trees in the canyon survive. If the wetland were to become completely channelized, the water would not soak into deeper layers of soil and the canyon would dry out. The trees provide important nesting habitat for birds such as the yellow warbler.
A nature trail at the Whitney Preserve, which is open to the public, runs through the area.
We needed to address the possible loss of the wetland near Cool Springs, said Jeff Symstad, conservation coordinator for the Conservancy. With the floods cutting a channel through the wetland, we faced the real possibility of losing the wetland and everything that depends upon it.
Due to the trees and permanent water, the diversity of bird species found at Whitney Preserve is more like the northern hills than the surrounding southern hills, Symstad said.
Symstad said that the project should be considered a temporary fix to protect the wetland from worsening erosion and that further work would be needed for a long-term solution.