Lake Wildwood Association
Sediment Basins and Stream Realignment

  • Scope:
    Two sediment basins were constructed and a creek was relocated to reduce erosion and prevent sediment from reaching Lake Wildwood.
  • Location:
    Marshall County, Illinois

The Lake Wildwood Association, Inc. (LWA) was awarded a Section 319 grant by the IEPA for the design and construction of stream and floodplain restoration Best Management Practices (BMPs). Hey and Associations, Inc. (Hey) designed the BMPs and performed construction oversight  for LWA.

Lake Wildwood is an impounded lake created for recreation on Shaw Creek.  The watershed is predominantly agricultural, encompassing approximately 11 square-miles. A solution was sought to reduce streambank erosion upstream and help capture suspended sediment before it reaches the Lake.

The streambank stabilization and realignment portion of the project addressed a 500-foot reach that included an eroding 30-foot high streambank along an escarpment. Realigning the Creek away from this bank was determined to be a better long-term solution than attempting to stabilize the slope. The material excavated for  the new stream alignment was used to fill the old channel.

Two sediment basins were also constructed in an open valley just upstream of the lake.  Both basins are offline and set near the grade of the existing stream bottom.  Rock riffles were constructed to direct flow through the basins during sediment producing storm events.  Since their completion, the basins have been observed to be actively trapping sediment as intended.

 

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