Hydrographic Survey, Topographic Survey, and Construction Layout Services
The work accomplished under this task order consisted of performing all necessary surveys associated with the Memphis District’s Revetment Construction and Maintenance Operations and Bank Protection Party. This work included projects on the Lower Mississippi River within Memphis, Vicksburg, and New Orleans Districts and any incidental work on an emergency basis that may occur on the Mississippi River where it relates to revetment construction and maintenance operations.
SEAS provided hydrographic, topographic, and construction layout services to support the Memphis District’s Revetment Clearing & Snagging (C&S) and the Grader Unit (GU) crews for four consecutive 5 month seasons from 2014 to 2017.
C&S support required 1 survey crew (three-man w/ RTK GPS system and Automated Singlebeam Survey Boat), staked and flagged each site for clearing, prepared to reach descriptions and sketches and performed hydrographic/topographic surveys of new bank failure areas.
GU support required 1 survey crew (three-man w/ RTK GPS System and an Automated RTK/DGPS Singlebeam Survey Boat), provided topographic surveys, construction slope staking, RTK Singlebeam hydrographic surveys and real-time data processing on-board the survey vessel. Overbank and hydro sections were surveyed multiple times daily to provide Cut Sheets, Cross Sections and Volumes in real-time to the GU dragline and grader operators. As-Built Surveys were performed for each site. The survey vessel was manned 10 hours a day for the entire duration of the project to provide Man Overboard Support. SEAS used Topcon GR3/5 DF GNSS receivers to establish site control from known NGS & USACE control and perform topographic data collection in the open areas of the sites. SEAS used robotic total stations to perform conventional traverses and collect topographic data in heavily wooded areas. All data collection was point and line coded per Memphis/AEC CAD standards and met USACE EM guidelines Singlebeam data collection performed using an Odom Echotrac CV100 Echo Sounder with a Trimble SPS461 GPS receiver and Teledyne TSS Dynamic Motion Sensor from a 22-foot survey vessel.