The Elk Bushkill stream restoration project is headed toward completion with construction in full swing. In-channel work will be completed in 1-2 weeks if no major rain events interfere. After this, planting to revegetate the site will begin. The Elk Bushkill flows through Burnham Hollow and flows into the Esopus Creek at Oliverea.
Hubbell, Inc. is building the project using a stream restoration design created by Stantec Consulting. The project is supervised on the ground by the Ulster County Soil and Water Conservation District on behalf of the Ashokan Watershed Stream Management Program. The project’s funder is the New York City Department of Environmental Protection.
Active stream restoration sites are impressive. The Elk Bushkill’s entire stream flow is diverted through a pipe while work on the channel bed and banks is underway. The stream flow can still be heard flowing through the pipe. Below the black water diversion pipe (on the right) is running past the now dry channel bed.
Hubbell is installing rock features that help to stabilize the newly designed channel’s margins until vegetation can regrow. The new channel is designed to resist down-cutting through soft clay sediments that are mixed into glacial till lining the 1,000 linear feet of stream under construction.
Looking toward the downstream end of the project site, Hubbell equipment operator Dave Cowan places large boulders into a stacked rock wall stabilizing the stream bank. Jesse Lyon, also with Hubbell, surveys the installation from top of the stream bank to make sure installation meets design specs.
As the channel is redesigned, thick clay is removed from the channel and trucked off-site to a disposal site away from any sensitive water bodies.
Other materials are retained on site and re-used in the channel design – stream cobble is left in place or pushed to the side to be placed back into the channel. Large, natural boulders are especially valuable when put back in the channel to create the potential for “pocket pools” to form on the downstream side of the boulder. These pools are good holding spots for small fish. The Elk Bushkill restoration design includes boulder sills, log vanes, and boulder clusters to promote fish habitat.
Below Project Manager Adam Doan (right) with the Ulster County Soil and Water Conservation District stands next to Tim Koch and Max Kelly (right to left) with Cornell Cooperative Extension of Ulster County. Adam’s left foot is resting on a rock sill installed in the channel bed to hold grade for a pool that will be constructed just downstream.
Below, a log vane is under construction. The root wad will provide roughness at the channel margin to slow water velocities near the stream bank and create habitat. The stacked rock on the stream bank is backfilled with soil to make sure no voids exist for flowing water to fill and erode. Large boulders were placed another eleven feet below the ground’s surface seen below – this rock must withstand high velocity stream flows in a steep mountain valley.
The entire site will be replanted after channel construction ends with willows and other plants. The plantings and other project features will be monitored for years by the Ulster County Soil and Water Conservation District. Once the last truck leaves the site, nature and the stream will do their work to regrow and evolve, but with less erosion through this now stabilized stream reach.