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Background:
In the late 1960's, and again in the 1980's the St. Louis District was directed
to study and define the need for interior flood control solutions in
From 1993 to 1996 the area again suffered severe interior flooding - the Federal Government (Federal Emergency Management Agency (FEMA), U.S. Army Corps of Engineers (USACE), Natural Resource Conservation Service (NRCS) spent tens of millions of dollars to provide emergency disaster relief, clean existing drainage ditches, and buy-out frequently flooded areas. However, this work was only a temporary solution.
Congress once again funded the Corps to re-evaluate this problem in 1997. With some forward thinking, the Corps determined that an ecosystem approach to this problem could potentially not only reduce many of the flooding problems, but could be of great environmental significance.
Issues
and Concerns:
Overall, The East St. Louis and Vicinity Interior
Flood Control and Ecosystem Restoration Project has the potential of
being a win-win situation by providing significant flood control using natural
ecosystems to accomplish the major job of temporarily diverting and detaining
peak rainfall events. With the Corps' history of concentrating solely on its
flood control mission, the challenge (made by participating resource agencies)
is to integrate ecosystem restoration into the overall study. Setting ecosystem
restoration goals, objectives and performance criteria has been critical. To
estimate the success of the ecosystem's restoration, the best available science
must be brought to bear. With areas of international cultural significance
found throughout the study's boundaries, the State Historic Preservation Office
has been an important advisor to the study team. In addition, agricultural
concerns play a heavy role in the decision making process, as a large portion
of the study area is comprised of very rich and unique agricultural areas
(Horseradish Capital of the World).
Possible
Solutions: 
In an on-going team effort to identify viable solutions to the complex issues
facing the area, the District has partnered with Waterways Experiment Station
(WES) and a number of the resource agencies, including the U. S. Fish and
Wildlife Service (USFWS), the Environmental Protection Agency (EPA), the
Natural Resource Conservation Service (NRCS), the Illinois Department of
Transportation (IDOT), the Illinois Department of Natural Resources (IDNR), and
the State Historical Preservation Office (SHPO), to ensure all stakeholder
issues are considered. The District developed a Hydrogeomorphic (HGM) model for
assessing wetland functions in the project area, and combined this evaluation with a multi-species
Habitat Evaluation Procedures (HEP) analysis to ensure that aquatic, wetland
and terrestrial system changes are addressed. Concurrently, a detailed
hydrological analysis of the area was performed to determine the natural flood
pulse of the area. These efforts were then evaluated for their potential flood
damage reduction benefits, in order to provide a complete systematic picture of
potential solutions.
Currently, several potential alternatives appear promising. These include
combinations of different sediment detention scenarios (upland vs bottoms),
channel/canal configurations, and restoration/development of some 5,000 acres
of habitat areas which would concurrently provide for the temporary diversion
and detention of rainfall events. These alternatives focus on areas that
provide suitable soils and hydrology necessary to reconnect a bottomland flood
pulse. Eight bottom areas are currently being analyzed further to determine
their viability, Old Cahokia Creek, Judy's and Burdick Branch,
Benefits:
When completed, the study will recommend restoration of a presettlement type
hydrology (flood pulse) to the project area. As a direct result, an increase in
biodiversity can be expected through the reestablishment of prairie areas,
forested wetlands, marshes, and meandering streams. The project will directly
improve water quality by reducing sediment loads throughout the ecosystem. The
project will serve as a case study for the integrated use of HGM and HEP in an
ecosystem context, demonstrating the effectiveness and power of these tools in
the evaluation of ecosystem restoration success. As a result the local area can
expect improved flood protection while developing and protecting significant
environmental resources, preserving open space and creating an overall improved
environment for the people of the area.
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