How does the Conowingo Dam capture sediment, and what will happen once the reservoir is full?

Bruce Michael, Director of Resource Assessment at Maryland Department of Natural Resources, visits the Conowingo Dam on the Susquehanna River to describe the hydroelectric plant’s evolving impact on the Chesapeake Bay watershed.

The Conowingo Hydroelectric Generating Station, or Conowingo Dam, is one of three dams on the lower Susquehanna River. While the reservoir behind the dam has long captured sediment—and the nutrients that are often attached—flowing downstream, reducing the amount of sand, silt, nitrogen and phosphorous entering the Chesapeake Bay, recent studies have drawn attention to its changing effectiveness as a “pollution gate.”

  • Produced by Will Parson
  • Music/Audio: “A Moment of Jazz” by Ancelin
  • Photography: Additional images by Wendy McPherson/USGS, Jane Thomas/University of Maryland Center for Environmental Studies and NASA Goddard Space Flight Center

Comments (3)

Bill Ball
November 02, 2019

Nice video, but I do offers two additional nuances to share:
1) the extra sediment and nutrient loads that come during high flows are dominated by “pass through” and only smaller amounts of scour at the truly extreme flows.  This is what justifies Bruce’s point at the end, about the importance of upstream measures over dredging.
2) Whenever “sediments and associated nutrients” are discussed, all should be cognizant that the vast majority of total nitrogen (N) from any watershed (including the Susquehanna) arrives to the Bay as dissolved nitrate and is not associated by sediments or affected by their release.  And though phosphorus (P) is dominated by sediment-bound forms, dissolved P is much more potent at causing algal blooms.

(These comments do not contradict those in the video, but I hope they are useful supplemental information for viewers!)

evie
December 20, 2017

good info very good info

speedy
November 28, 2017

good video

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