Crow’s Nest: Culvert Replacement on French Creek

At last the seasons and weather have cooperated so that the culvert replacement that was begun last year could be completed. Last year’s record rainfall kept the stream flow too high for the work to proceed, and then no work in the stream could be done during fish spawning season. We are lucky to get the project completed before the permits expire.

The excavating is being done by a contractor but the concrete forms are built by Natural Lands Trust’s Building Stewardship Staff. In the photo above Steve Holmburg is preparing the form for the second pipe. Below, that pipe has been rolled into place and is about to be pushed into the wooden form.

This has been a big project for our staff and involved exhaustive work by Bob Johnson, Steve Holmburg, Scott DeBerardinis, Luke DiBerardinis, David Casteneda, as well as biologist consultant Scott Bush and excavator C. M. Kristman.

The new culverts will carry many times the flow of the old “oil tank” culvert. They are better aligned with the stream, which explains why they are so much longer: the road that goes over them will cross them at an angle. The pipes are canted downstream slightly and a retaining lip at each end will ensure that the bottoms inside remain with a natural stream sediment and stone floor—important for stream habitat.

The service road over the culverts should be open in just a couple weeks, effectively re-opening the part of the preserve on the west side of French Creek. It also provides an off road connection between the Piersol Road and Bethesda Road, between the visitor center of Crow’s Nest Preserve and the Horse-Shoe Trail and Hopewell Furnace National Historic Site.

We will begin replanting native shrubs along the streambank here at a volunteer day this fall.

Posted by Daniel Barringer on July 31, 2012.