Patapsco River Fish Ladder Damaged in Storms


Bloede Dam, Patapsco River, MD | NOAA

Bloede Dam, Patapsco River, MD | NOAA

Earlier this month, I shared a blog about fish ladders and the challenges that fish face in using them. It turns out that a big storm that week really wreaked havoc on a fish ladder at one of our dam removal project sites— the Bloede Dam in Patapsco Valley State Park, Maryland.

We have been working on removing dams on the Patapsco River for a number of years. Bloede Dam is the farthest downstream, and its removal would open up access to more than 50 miles of habitat upstream for migratory and resident fish. The fish ladder at the dam is not particularly efficient— one of the reasons that makes removal of the dam desirable. In fact, we have been unable to document the use of this ladder by migratory fish in the past three years of monitoring.

Boulders blocker fish ladder on Bloede Dam, Patapsco River, MD | Jim Thompson

Heavy boulders fill the entrance to the fish ladder at the base of Bloede Dam following a recent storm | Jim Thompson

Now, apparently, any prospects for use of the ladder by fish (migratory or resident species) this spring have been abruptly halted. The recent storm has filled the bottom section of the ladder near the base of the dam with heavy boulders. This situation will require significant manual labor and/or mechanized equipment to open the ladder up again. The top of the fish ladder was also clogged with logs and other debris that had floated downriver during the storm. Given that the spawning run for blueback herring is currently peaking, it will likely be too late to have it open for any significant fish movement this spring. 

The current situation with the fish ladder at the Bloede Dam is not unique. This is a challenge facing private dam owners and state resource agencies across the country. Fish ladders require ongoing maintenance to ensure that they continue to function at their optimal capacity. Imagine the challenge of keeping a private dam owner invested in upkeep of their fish ladder!

However, even under the care of a watchful eye, nature can throw a wrench, or in this case a bunch of big rocks, into even the best managed fish ladders. What a challenge moving fish up rivers can be! This is why dam removal often shakes out as the best option to ensure adequate fish passage on rivers.

Fish ladder damage at Bloede Dam, Patapsco River, MD | Jim Thompson

After a recent storm, the exit at the top of the fish ladder at Bloede Dam is completely covered in sticks, logs, and debris | Jim Thompson

We will be celebrating World Fish Migration Day at Patapsco Valley State Park on May 24th! If you are in the area, come spend the day enjoying the river. You won’t regret it!

Learn more about our work to remove the Bloede Dam.