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 Since the 1930s, Point Au Fer Island in Terrebonne
Parish, Louisiana, had lost about 15% of its
marshland area due to subsidence, shoreline erosion
and the scouring out caused by strong tidal
exchanges between southeastern Atchafalaya Bay and
Fourleague Bay short-cutting through the Lake
Chapeau marshes as a result of man-made oil-gas
canals intersecting natural water ways. Spoil banks
associated with canal excavation had also created
artificial impoundment areas and disrupted natural
hydrologic patterns.
The Louisiana Department of Natural Resources
contracted BKI to re-establish a hydraulic
separation of the two watersheds and to restore
island hydrology by re-establishing hydrologic
control points.
To separate the two watersheds, BKI used more than
867,000 cubic yards of fill dredged from the
adjacent bay placed across the western end of the
barrier island. To restore the island’s hydrology,
BKI designed the construction of seven
rock-and-riprap channel plugs, the cutting of gaps
in spoil banks lining the canal, and the dredging of
a 6,700-foot reach of Locust Bayou. The project
resulted in the natural drainage patterns being
restored and the rapid erosion being slowed.
Construction cost was approximately $3.14 million.
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