Mitchell Brook Aquatic Organism Passage Culvert Replacement

Princeton Hydro was hired by The Nature Conservancy to design and permit the replacement of the Mitchell Brook culvert in Whatley, MA. The culvert was designed according to the Massachusetts Stream Crossing Standards to promote aquatic organism passage.

Road crossings over streams have gained recent attention in the Northeast for interrupting stream continuity, fragmenting habitat, and creating barriers to fish passage. The USGS, in partnership with other agencies, had been collecting fish passage data at two road crossings in a small rural watershed in western Massachusetts.

The Nature Conservancy contracted Princeton Hydro to design and implement a culvert crossing retrofit that would allow for before-and-after comparison of fish passage rates on Mitchell Brook, a tributary to the West River. As one of the few stream crossing retrofits with extensive fish passage data collection, the project is intended to serve as a model for ongoing efforts.

Princeton Hydro completed a geomorphic assessment and hydrologic and hydraulic modeling, and applied the USFS Stream Simulation process to develop a design that satisfied the Massachusetts Stream Crossing Standards. As the crossing was a public road, the design also had to satisfy MassDOT road and bridge standards. Princeton Hydro gained the necessary permit approvals from Massachusetts Department of Transportation, the local Conservation Commission (administering state Wetland regulations), and the US Army Corps of Engineers.