River ecological restoration using process-based hydrogeomorphic reconstruction: A case study of Kissimmee River in the United States

Abstract

[Objective] The Kissimmee River Restoration Project aims to address ecological degradation caused by human activities by rehabilitating riverine habitats, restoring biodiversity within the basin, and reducing pollution to downstream lakes, while simultaneously maintaining the river's flood-control function. [Methods] To restore hydraulic connectivity between rivers and lakes and between rivers and floodplains, during the restoration of Kissimmee River, water flow was first redirected into the original river channel by backfilling artificial river channels, and then the discharge volume of the upstream reservoir was controlled to simulate historical hydrological conditions of the downstream river. The scouring effect of the water flow addressed the issue of nutrient accumulation in the original river channel. Meanwhile, the natural channel morphology of the original river channel and the erosion and sedimentation in the hydrological process were leveraged to restore the meandering of the river. In order to restore the biodiversity of the river basin, the project regulated discharge of the upstream reservoir to reinstate seasonal flood inundation patterns in the riparian zone. Additionally, the extensive floodplain wetlands downstream were reconstructed, providing habitats for numerous animals, plants, and microorganisms. [Results] After more than 20 years of implementation, the Kissimmee River Restoration Project achieved remarkable result. Water quality improved notably, with a significant increase in biodiversity across the river basin ecosystem. Riparian wetlands largely restored their water storage and flood control functions, while also purifying natural water bodies and providing habitats for wildlife. [Conclusion] The Kissimmee River Restoration Project has not only rectified the destructive consequences of human intervention in the natural environment, but has also become an important milestone in global ecological management and restoration practices. The successful implementation of the project has improved biodiversity and water quality, while bringing positive benefits to the local society and economy, such as protecting agricultural development and promoting natural tourism. This case demonstrates the key role of hydrogeomorphic restoration in the ecological restoration of rivers and lakes. The underlying restoration logic of the project conforms to the current principles of Nature-based Solutions, integrating flood control with ecological environment protection to achieve the stability and sustainable development of the river ecosystem.

Keywords

Kissimmee River / hydrogeomorphology / river ecosystem / de-channelization / ecological restoration project / implication / influencing factors