User:CONeal19/Floodplain restoration

Floodplain restoration is the process of fully or partially restoring a river's floodplain to its original conditions before having been affected by the construction of levees (dikes) that break the connection between the floodplain and the river, or the construction of ditches that drain wetlands and marshes.

The objectives of restoring floodplains include the reduction of the incidence of damaging floods, the provision of habitats for aquatic species, the improvement of water quality, and the increased recharge of groundwater in an attempt to return the floodplain to it's pre-modified state.

Techniques
Floodplain restoration is usually first addressed by identifying human activities resulting in degradation of habitat and creating a management plan to stop or limit the habitat loss. Once degradation has affected the hydrology of a floodplain, the water regime itself must be restored in order to restore the ecological processes of the floodplain. A wide range of floodplain restoration techniques exist that can be organized into different categories, with the most successful restoration projects resulting from thorough data assessment and a plan that addresses the specific needs of the restoration site. Assessing the efficacy of restoration plans during the restoration process and adapting methods and techniques as needed is essential to the restoration project, and results in a higher success rate over a shorter period of time.

Passive Water Regime Management
Passive water regime management are techniques involving creating new pathways for water flow and blocking existing pathways, or enhancing present pathways and removing blockages. These techniques are passive because they do not involve controlling the water flow directly through the use of levees, dams, or other man-made devices, but by reestablishing the natural flow of the stream through the floodplain. Passive management can include methods such as excavating new channels, removal of dams and levees, reconnecting streams to other water bodies and floodplains, and reshaping the streams' bed and banks. Passive water management plans are often designed with a goal of restoring the general geography of a floodplain with improved water quality and organism abundance, diversity, and function as secondary results.

Active Water Regime Management
Active water regime management uses techniques that control the flow and location of water by physically moving the water using man-made structures such as sluices, weirs, and dams. These techniques can be used to reduce or increase flow rate, create and manage lakes, or to reintroduce seasonal inundation to the floodplain. The goal of active water regime management is often specifically based on reestablishing flora or fauna populations and diversity.

Vegetation Facilitated Restoration
Vegetative communities in the floodplain help maintain water quality and regulate biogeochemical processes. Due to their strong influence on floodplains, vegetative communities are often a key focus of floodplain restoration projects. There are several restoration techniques that can be used for restoring plant communities in floodplains such as reintroducing terrestrial plants by planting seeds and sod, facilitated restoration using the existing seed bank, and using inundation to allow for nearby aquatic populations to reestablish.