MDC undertakes new vision for Columbia Bottom Conservation Area
SPANISH LAKE, Mo.—The Missouri Department of Conservation (MDC) is implementing a new vision for Columbia Bottom Conservation Area in Spanish Lake. Going forward, MDC’s strategy will focus on managing the area to work with the natural flooding cycles of the river and cultivate the habitat benefits of a healthy floodplain. This will provide important wetland habitat for wildlife, flood relief for neighboring areas, and unique recreational opportunities for area users.
MDC purchased the 4,318-acre tract in 1997 to create an urban conservation area. Columbia Bottom is at the Confluence of the Missouri and Mississippi rivers, North America’s largest rivers. Located in the natural floodplain of these two rivers, the area has always been prone to flooding.
The frequency of major flood events has increased over the last decade with high water events occurring in 2008, 2013, 2015, 2017, and 2019. Each of those times, Columbia Bottom has been inundated with water to the extent that MDC has been required to close the area until waters have receded. Water covered the area for almost six months during the 2019 event.
This has created expensive damage and resulted in a repetitive and unsustainable repair cycle. Significant debris and sediment have been deposited on the area, existing wetland pools, and at the confluence, where sediment is two-to-four feet deep.
Efforts to hold back the rivers with levees, repair damage, and manage the area for waterfowl hunting are incurring costs to Missouri taxpayers through expenses, MDC staff time, and resources that are no longer practical.
MDC has identified the need to re-think the management goals of Columbia Bottom in order to create a sustainable balance between natural resources, human recreation, and responsible financial investment in one of St. Louis County’s most important natural assets.
As part of a new management strategy, MDC will remove portions of the existing levees, which have been compromised by previous flood events, and allow the area to flood naturally during high flow events. This will enable Columbia Bottom to assume its natural ecosystem function of a wetland, to slow, hold, absorb, and dissipate water during food events.
MDC will construct a setback levee on the south side of the area to help protect downstream neighbors. This will restore floodplain connectivity to an additional 3,500 acres on the conservation area and will reduce flood impacts downstream. MDC is budgeting $12 million to supplement $15 million in funds distributed from the American Rescue Plan Act (ARPA) to pay for the new setback levee.
A benefit to this strategy is connecting the river and wetland habitat during natural flood cycles, which has largely been disconnected across these major river floodplains. During floods this will benefit many riverine fish. As the waters recede, other wetland dependent species, including migratory birds, reptiles, and amphibians will take advantage of flooded and drying pools.
The costs to repair and maintain Columbia Bottom’s aging river pump station make it impractical to continue the area’s intensively managed waterfowl hunting program. Therefore, MDC will discontinue strategies that depend on artificially manipulating area water levels. Future waterfowl management at Columbia Bottom will focus on creating dry field hunting opportunities by planting winter wheat. This will produce opportunistic waterfowl hunting during wet conditions.
MDC will continue to provide dove hunting opportunities by planting and manipulating sunflower and small grain crops. The new management strategy should also increase the diversity of birds and wildlife drawn to the area, which will benefit birders, photographers, and wildlife watchers.
Under this new vision, Columbia Bottom will function with the river to resume its important ecosystem role as a floodplain and wetland, which will better mitigate the effects of future flood activity. It will create important habitat for native plants and wildlife. And it will continue to offer unique outdoor recreational opportunities just 20 minutes from the urban St. Louis core.
Columbia Bottom Conservation Area is located off Riverview Drive, approximately three miles north of I-270.