Dredging for Particle Tracing Study in South Padre Island Wraps Up

Dredging of the Brownsville Ship Channel was completed in July as part of the Nearshore Berm Nourishment Project and Particle Tracing Study in South Padre Island in Texas.

This multi-year project is being done through a partnership of the City of South Padre Island, the U.S. Geological Survey (USGS), Texas A&M – Galveston, the U.S. Army Corps of Engineer Research and Development Center (ERDC), and Partrac, a United Kingdom-based company that deploys tracer sand for particle tracing studies.

Beginning in May, the Corps used the hopper dredge McFarland to remove 226,000 cubic yards of sand from the channel and placed it nearshore of South Padre Island. The third week of June, Manson Construction Company took over the project using its dredge Bayport. Bayport transported sand from the entrance channel to a placement area on the nearshore berm. In total, 408,000 cubic yards of sand was removed and placed on the berm.
An additional 4,000 pounds of coated tracer sand was deposited into the nearshore berm by the MV Isabella operated by Breakaway Cruises. The tracer sand matches the grain size of the sand but has magnetic and fluorescent colored pigment coating applied to each of the individual particles using a polyester resin binding agent. The coating allows officials to track the movement of sand deposits from the nourishment project as it moves along the shore. The goal is to determine how much dredged material finds its way to the beaches and how fast the beaches erode.

Samples will be taken from designated areas to determine how much tracer sand has made it to shore. Offshore sampling occurred daily through August 21 and onshore sampling was done on August 22. Final data analysis is expected to be completed next summer with a final report estimated for completion in February 2020. Prior to the final report, the USGS and Corps will issue their own reports on the study.