MISSISSIPPI RIVER ROCK PINNACLE REMOVAL, THEBES ILLINOIS
Arc Surveying & Mapping, Inc. has performed multibeam swath bathymetric surveys of the Mississippi River from New Orleans, Louisiana to Thebes, Illinois for various US Army Corps of Engineer districts.
At Thebes Arc located rock pinnacles in the river bottom which were hazards to navigation during extremely low water river levels. Surveys were performed in conjunction with the St. Louis District ACOE and various dredging contractors.
Prior to the introduction of multibeam swath depth sounding systems, hydrographic surveys were performed utilizing single beam depth sounding, usually at 100 ft cross sectional line spacing and often missing rockpinnacles between cross-sectional stations.
At low water stages during droughts, these in situ pinnacles and boulders missed by previous surveys, posed a hazard to navigation to the Mississippi River barge transporting industry.
Multibeam surveys by the ACOE resolved the problem and programs were developed by the ACOE for the removal of these obstacles.
RIVER MILE 44SOUTH OF MO-IL RAILROAD BRIDGE
Multibeam surveys were performed by Arc daily and provided to the removal constructor excavator in xyz format for input into the excavator software.
Pre and post construction survey data was processed on site and transmitted to Arc’s Jacksonville, Florida office for daily QC and quantity calculations.
Survey data, quantity calculations and maps were provided to the St. Louis District daily.
Coordination with river traffic and planning the movement of dredging equipment provided a safe an incident free project.
NOTE: the ice-free location at the bow of the dredge, previously occupied by the Arc survey vessel at the conclusion of dredging.