Abstract: Session A  9:10 am (Back to Session A)
Columbia Lake Dam Removal; Using Drones for Quantitative Evaluation of River Restoration

Beth Styler-Barry
The Nature Conservancy
Chester, NJ

Authors: Beth Styler-Barry, Geoffrey Goll, PE, Kelly Klein, Christiana Pollack, CFM, GISP, Casey Schrading, EIT, Steve Lyon, Ellen Creveling, Drone Team: Dave Zuckerman, Chuck Gullage, Nigel Robinson, Jeff Burian

The Columbia Lake Dam was built in 1909.  This 18- foot high, 330-foot-long dam was located on the Paulins Kill less than 0.25 miles upstream from its confluence with the Delaware River and created an impoundment that stretched more than 1.5 miles upstream.  In the last several years, the hydropower production was deemed to not be profitable and became a candidate for removal.  As part of The Nature Conservancy’s (TNC) mission to improve the quality of the Paulins Kill, removing this “first blockage” was the cornerstone of the larger mission.  Its removal would result in the opening of 10 miles of river for fish migration, improved recreation access, floodplain reconnection, habitat enhancement and higher water quality.

Dam removal activities commenced in June 2018 and will continue through the Spring of 2019, followed by five years of monitoring.  This is the largest dam removal in New Jersey to date and is the first to use passive efforts for sediment management; including adaptive management planning and extensive on-the-ground monitoring.  Monitoring of the effects of dam removal on the river and its ecosystem is vitally important to determine long-term ecological uplift, short-term positive and negative effects, and develop data to provide information for future dam removals.

TNC is interested in understanding the effectiveness of drone or UAV technology to evaluate the effects of the dam removal; including the calculation of increased floodplain habitat, development of vegetation communities, changes in sediment deposit elevations and distribution, and channel migration evolution.  And, as a result of the programmable and repeatable nature of drone flight paths, such monitoring will be able to be conducted for years and decades, producing invaluable data for research and future project design.

The presentation will review the various parameters investigated, the results and significance of the data retrieved, and recommendations for the use of this technology for future ecosystem restoration projects.  Checks on the data will be presented, including the comparison between the elevational data collected by the drone flights and land survey elevations of selected cross sections through the former impoundment.