St. Johns/New Madrid RSEIS - Endangered Species & Wetlands ...

It has been estimated, based on current construction costs, that new levee construction
within the project area would cost approximately $2.4 million per mile. It has also been
estimated that 12.8 miles of new levee construction would be required to create 16,750
acres (assuming 50% duration) of additional floodplain that could be reforested. Based
on this assumed length, the estimated construction costs would be approximately $30.7
million. There would also be additional real estate costs (acquisition or easements) of
approximately $33.5 million.
Realigning the Mississippi River Frontline Levee was deemed unfeasible due to the
expected cost of new levee construction.
2.5.3 Reconnection of Historical Waterways Through the Levee
Reconnection of historical waterways through the Mississippi Mainline Levee would
require the construction of a culvert or some other similar device. Based upon
preliminary planning and cost estimates developed for Big Oak Tree State Park,
reconnection of additional historical waterways through the levee is cost prohibitive.
Additionally, this technique would require the provision of fish access, which is not
assured depending on the nature of the water reconnection (see below). Therefore,
reconnection of historical waterways through the levee system was not considered in
detail.
An exception to not considering reconnection of historical waterways is the Big Oak Tree
State Park water supply feature that may reconnect the historical channel of St. James
Bayou through the levee. The Corps is evaluating this feature in detail. The Corps plans
to provide fish access into the park and 1,800 acres of surrounding lands. One additional
location other than through St. James Bayou has also been considered and is located
southwest of the park near the Mississippi and New Madrid County line. The water
delivery system has not been designed to date. Therefore, benefits to mid-season fish
rearing habitat cannot be quantified at this time. Fish passage would be considered
throughout the design of the water supply feature. The site would be monitored and
appropriate mitigation credits would be calculated if fish can obtain access to the park
and the surrounding 1,800 acres of lands acquired and reforested for compensatory
mitigation.
There is no evidence to support the assumption that the New Madrid Floodway box
culverts would impede fish access. Further information concerning fish access through
the New Madrid closure levee is found in Section 4.3.2.1 of this RSEIS 2.
2.5.4 Modified Closure Location
The 2002 RSEIS analyzed several closure locations to minimize damages to floodplain
fish habitat. The current location was selected because, unlike other locations analyzed
in that document, it maximizes economic benefits, compensates for all significant
impacts to fish and wildlife resources, and has a positive cost of construction to benefit
Draft RSEIS 2
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