US Army Corps of Engineers
Rock Island District Website


Clarence Cannon National Wildlife Refuge Habitat Enhancement and Restoration      

St. Louis District

Pool 25, Upper Mississippi River, Miles 261 - 264,  Pike County, Missouri, Congressional District: Missouri - 6th


  • US Fish and Wildlife Service 


Project Location. Clarence Cannon National Wildlife Refuge (CCNWR) HREP is located along the right descending bank of the floodplain within the Upper Mississippi River Navigation Pool 25 between river miles (RM) 261.1 and 263.8, adjacent to the town of Annada in Pike County, Missouri.  Clarence Cannon National Wildlife Refuge covers 3,750-acres of seasonally flooded wetlands, open marsh, mixed shrub/scrub/emergent wetlands, bottomland hardwood forest, agricultural fields, backwater lakes and sloughs, and floodplain forest.  The CCNWR HREP would be constructed on land owned by the Federal Government with management responsibility provided by the USFWS.

Problem Identification. In the early 1900s, the area was drained, ditched, leveed, and cleared for agricultural production in fragmented parcels which altered the site hydrology and resulted in large-scale conversion of native plant communities (floodplain forest and emergent wetland) leading to  disturbed and degraded ecosystem structure and function.   Currently, on the 3,750 acre refuge, approximately 3,200 acres are fragmented into 27 named units capable of limited manual water level alteration, and this fragmentation has eliminated the natural drainage, topography, and habitat connectivity of the project area.  In addition, forest resources on the refuge, primarily pin oak and pecan, were impacted by the flood of 1993.  Up to 80% of the floodplain forests in the approximate 400 acres of forest died due to the flood.  Furthermore, backwater sloughs, lakes, and old meander scars have been cut-off from the river by the exterior berm.  Almost all of these aquatic areas are greatly deteriorated due to lack of connectivity with the main stem Mississippi River.  This has greatly reduced aquatic habitat diversity and important seasonal habitat for a diverse suite of aquatic organisms.  Furthermore, due to the altered hydrology and loss of native wetland vegetation, non-native reed canary grass is spreading across the site resulting in further ecosystem degradation.

Project Goal and Objectives. The goal of this HREP is to restore and improve the quality and diversity of wetland ecosystem resources in the project area.  

Objective 1. Restore native wetland plant communities (forest and emergent wetland) in areas of suitable elevation, hydrology, and soil – Decrease habitat fragmentation between the management units to restore historic vegetation patterns. Restore forest and other wetland species at suitable elevations, soils, and hydrology. This would restore wetland habitat to the interior of CCNWR.

Objective 2. Improve aquatic ecosystem resources – Increase aquatic habitat diversity and floodplain topographic diversity.  Restore seasonal connectivity between the project area and the Mississippi River.

Objective 3. Improve water drainage and delivery – Deliver water to achieve target surface water levels in < 7 days within the management units. This would provide the project partner improved water conveyance management capability on the management unit(s) which will increase wetland plant diversity, increase invasive species management capabilities, and improve overall ecosystem resources.   In addition, during large, overtopping flood events, drain the interior project area to target water levels in < 40 days which is needed to prevent ponding of floodwaters which is detrimental to wetland structure and function.

Quick Facts

  • Approximate Acres: 3750
  • Congressional District: Missouri - 6th
  • State(s) Covered: MO
  • Land Ownership: USFWS
  • Management Agency: USFWS
  • Management Authority: Refuge

Recommended Features

  • Setback berm with exterior berm degrade
  • Three larger management units and associated water control structures and native wetland vegetation restoration
  • Restoration of historic meanders 
  • Diesel pump station
  • 300 acres of floodplain reforestation


  • The Fact Sheet was approved 8 September 2010
  • Definite Project Report with Integrated Environmental Assessment Approved 23 May 2014
  • Plans and Specifications underway