NAME OF APPLICANT: Terrebonne Levee and Conservation District; c/o APTIM, 2503 Petroleum Drive, Houma, Louisiana 70363.
LOCATION OF WORK: Within the Terrebonne Basin, in the West- Central Louisiana Coastal hydrologic unit (HUC 08090302), located in the Houma Navigation Canal (HNC), approximately 4 miles southwest of Dulac, Louisiana, in Lafourche Parish.
CHARACTER OF WORK
: The applicant proposes to dredge an area, construct an
aggregate road for access, and construct a lock structure that provides 110 of clear
width and an 800 foot long lock chamber, floodgate with integral sluice gates, a closure
wall that consists of a pile-supported T-wall floodwall to connect this project to existing
adjacent levees, an operations area, maintenance building, boat ramp, boat shed, and
other appurtenant facilities to maintain and operate the structures. The existing
floodgate and floodwalls will be removed or incorporated into the proposed flood gate
and lock complex. A total of 21.4 acres of brackish marsh will be impacted by
construction of the lock structure. Approximately 1,383,000 cubic yards of material will
be dredged from the HNC and the proposed marina canal. All dredged material will be
deposited beneficially in 245 acres of open water in the nearby area, as shown in the
enclosed disposal plan. Approximately, 37,600 cubic yards of hauled-in dirt will be used
for the levee tie-in and as backfill for utilities, while approximately 236,000 cubic yards
of rip-rap and 2,400 cubic yards of concrete will be used for the levee tie-in and bank
line stabilization/scour protection. Approximately 19,500 cubic yards of limestone and
6,000 cubic yards of asphalt will be used for the access road.
According to the applicant, the project footprint has been minimized to the maximum extent practicable. The alignment and design have been altered such that wetland impacts were reduced from 130 acres to 21.4 acres. Other alignments evaluated resulted in additional wetland impacts.