The Buckhorn mine's Aquatic Management Resources Plan requires that the mine provide mitigation for reduced flows that result from dewatering the Buckhorn mine. Part of this mitigation includes protecting and restoring aquatic habitat and wetlands on the Myers Creek mitigation site (also known as the Thorp property). When several rounds of riparian plantings installed by Kinross at the Myers Creek mitigation site failed, the agencies and the company settled on a different plan. To meet their mine mitigation requirements, the company has replaced a culvert that posed a barrier to fish at Bolster/USFS road 3575. The project helps satisfy the requirements for Kinross to offset the environmental impacts of the Buckhorn mine.
The above left two photos show the upstream end of the culvert, where it is imperative to avoid headcutting of the channel in response to the culvert replacement. Directly above: This concrete apron presented more than a two-foot drop for trout, from the bottom of the outlet to the surface of the stream (depending on the time of year). Trout could be seen attempting to jump.
The original culvert not only created a fish passage barrier in the substantial distance between the culvert bottom and the stream, but also in the culvert itself, which was undersized. Too much water flowing through too small a diameter culvert makes it impossible for fish to pass. The bottom of the new culvert mimics the conditions of a natural streambed and facilitates passage.
Fish will now be able to freely pass under the road, increasing habitat connectivity in this part of the Myers Creek watershed. Cattle have been excluded from the vicinity of the inlet, and the outlet remains fenced as required by the mine’s mitigation plan. Mitigation is intended to compensate for the loss of stream, wetland, and/or other functions of aquatic resources. This is a positive step forward for fish passage.
If you have trouble with the slideshow, please view the culvert pictures here