Rip Rap Landing Habitat Rehabilitation and Enhancement Project
St. Louis District
Pool 25, Upper Mississippi River, Miles 260 - 267, Calhoun County, Illinois,
Congressional District: Illinois - 13
- Illinois Department of Natural Resources
The Rip Rap Landing HREP is located in Pool 25 of the Mississippi River along the left descending bank between river miles 260.5 and 267 in Calhoun county, Illinois. Rip Rap Landing covers 2,338 acres of river bottomlands, of which 2,055 acres are owned by the Illinois Department of Natural Resources, and 283 acres are owned by the Corps of Engineers as General Plan Lands, known as Dog Island.
The historic Sny River channel, now known as Sny Creek, traverses the project area from north to south and forms a portion of the east property boundary. The Old Sny Island Levee extension also divides the project area with lands on the riverside being subject to flooding and over-bank scouring, while lands on the west are less impacted because this remnant levee acts as a sediment deflection berm reducing scouring flows and river-borne sedimentation. Additionally, floodwaters back into the lands east of the Old Sny Island levee extension, depositing progressively less silt as it inundates areas further north. For planning purposes, the project area was divided into zones:
Zone 1 is on the northernmost end of the project area and is contained within the Sny Island Drainage and Levee District, and therefore, unlikely to be flooded by the river.
Zone 2 , State Natural Area, is not protected from Mississippi River flooding and has been designated a State Natural Area due to significant historic forest composition of bottomland hardwood forest. This zone lost many trees during and after the flood of 1993, and currently the invasive grass species, Reed Canary Grass, is becoming established throughout the zone.
Zone 3, Roadside and Waverly Lake Wetland Management Area, is part of the original IDNR acquisition and consists of wetlands managed primarily for migratory wildlife and has a small disconnected lake. IDNR attempts water level management in this zone with spring and early summer drawdowns to promote growth of moist soil vegetation followed by a fall flood to provide habitat during the fall migration. This zone has suffered due to insufficient water conveyance capability.
Zone 4, Rust Land Company-Wetland Reserve Program Easement, is located adjacent to the Mississippi River. A natural levee has formed along the river but low spots within this levee allow for headwater flooding resulting in wetland scouring and river-borne sedimentation in the zone. Most of the zone was in agricultural production. The former agricultural fields are dominated by herbaceous vegetation preventing regeneration of trees. Furthermore, the invasive species Reed Canary Grass is becoming established throughout the zone. Generally, insufficient water has been available optimum wetland management.
Zone 5, General Plan Lands-Dog Island, is the southernmost part of the project area, located at the confluence of Sny Creek with the Mississippi River. The Sny Creek channel has been impacted by sediment from both the river and the hillside watersheds that drain into the creek, reducing depth of the creek to two feet or less and cutting off fish access from the Mississippi River except during periods of flooding.
The overall project goal is to increase the quality and quantity of aquatic, non-forested wetland, and forested wetland habitats. The objectives for the project include: 1) Improve aquatic ecosystem resources; 2) Increase native plant species diversity and reduce the number of acres impacted by invasive plant species by improving water level management; 3) Reduce impacts of headwater flooding and river-borne sedimentation; and 4) Increase quantity and quality of bottomland hardwood forest.
- Approximate Acres: 2300
- Congressional District: Illinois - 13
- State(s) Covered: Illinois
- Land Ownership: State of Illinois
- Management Agency: ILDNR
- Management Authority: State Conservation Area
Proposed Potential Features
- Supplemental pump
- Excavating Sny Creek
- Reconnecting Roadside Lake to Mississippi River via Sny Creek
- Water control structures to improve water conveyance throughout the project area
- Pump Station
- Revetment along low spots within natural river levee
- Tree planting
- The Fact Sheet was approved in November 2007.
- Feasibility Study underway.