Dam Removal on Little Gunpowder Restores Anadromous Fish Passage

Grey clouds soar quietly in the wet sky above and reflect along the sparkling waves of the Little Gunpowder that flows through Monkton, Maryland. To most in the area, May 6, 2020, serves as just another rainy day in the “new normal”. To Ecotone, a welcome challenge awaits, teasing the potential for a new and improved thriving ecosystem. The only thing standing in Ecotone’s way? A historic, 60 foot-wide, 6 foot-tall, concrete dam built in 1968.
 
Per the current landowner’s accounts, the dam powered a water pump that conveyed water to the farming operations on the property. The original purpose phased out quite some time ago, and the dam stands merely as a fortification, inhibiting fish passage.

Ecotone utilized mechanical means to demolish the dam by way of a 50,000-pound tracked excavator and a 10,000-pound hydraulic hammer. The existing concrete was notched incrementally to decrease the backwater at a controllable rate. With all the backwater released; demolition commenced.  What took probably weeks to originally construct, got reduced to rubble in a matter of hours or in just under ten seconds as seen in this video. Ecotone removed concrete remnants from Little Gunpowder River and replaced the dam with a riffle structure. Built entirely from existing, natural river gravels that had collected behind the dam over the past 50 years, the riffle structure adds vital habitat for aquatic inhabitants.  “The transformation in such a short timeframe has been truly quite amazing.  If you didn’t know it, you would never guess there was ever any man-made structure blocking this river at all!” said Chris Kidd, Ecotone Project Manager.
 
At about 25 miles in length and contained within a 4,000-acre watershed, Little Gunpowder River, a natural boundary between Baltimore and Harford County, runs through Gunpowder Falls State Park, Maryland’s largest state park.
 
Thank you’s go out to the Harford Soil Conservation District, the Chesapeake and Atlantic Coastal Bays Trust Fund, a very gracious and environmentally mindful landowner, and the Ecotone staff who helped make this landmark removal possible. Through vital partnerships, a historic dam’s reign ends; and the renewed life of a babbling, unrestricted river system begins.