Colorado TU staff recently joined colleagues from the U.S. Forest Service for a site visit to the Corral Creek fish passage and temporary barrier project site, to inspect work completed this year. Winter weather has already set into the project area, and driving to the project site proved challenging though the Forest Service jeep, with the assistance of chains, was able to make it.
The Corral Creek fish passage/barrier project is a unique combination of a long-term fish passage structure – a larger culvert with a simulated streambed bottom to facilitate free passage by fish – along with a temporary barrier to isolate the upstream habitat for native fish until downstream areas can also be restored to native fish habitat, at which point the barrier will be removed to reconnect the habitat. The installation is a challenging one, managing a roadway, appropriate culvert and fish passage features, a large steel-plate barrier, and a downstream concrete splash pad and rock apron, all of which need to work together to achieve the required end result. Corral Creek is just one phase of the larger Poudre Headwaters Project, aiming to restore Greenback cutthroat trout to nearly 40 miles of connected habitat in a series of phased restoration efforts.
When we arrived, we were greeted by an impressive sight: the large natural-stream-bottom culvert that was previously installed now has the steel plate fish barrier mounted at its outlet, pooling water up through the culvert and above the road crossing while creating a five-foot drop to prevent upstream movement of non-native fish from below the culvert. With the winter weather, ice had formed all along the face of the barrier wall, creating a frozen waterfall on the downstream side of the road crossing.
The inspection did yield at least one area needing additional work in the new year – the road will need to be widened additionally over the culvert to meet road specifications. Colorado TU’s contractor will work on that final task when weather allows in late spring/early summer of 2025. We will return to the site for further inspection after snowmelt to verify that other aspects of the project are operating as intended. Once work on the barrier is completed and its effectiveness confirmed, Colorado Parks and Wildlife, the Forest Service, and TU will collaborate on removal of non-native fish above the barrier – followed by reintroduction of Greenback cutthroat trout into their newly restored home in upper Corral Creek.
