Benefits of Natural Floodplains

Next

Natural floodplains can mitigate flooding by slowing water velocities and providing storage for flood water.

Floodplains offer hydrologic regimes that can create unique habitat for species such as fish and amphibians. Floodwaters can create saturated conditions within the floodplain offering space for hydrophytic vegetation and wetlands.

Floodplains support groundwater recharge by providing storage volume for water to settle and percolate into the land surface following storm events and flooding. As the water infiltrates into the ground, it recharges the available storage within aquifers.

The presence of vegetative floodplains aid in nutrient removal, help mitigate eutrophication, and increase the water quality for downstream waters.

Natural floodplains have wide overbank areas that reduce water velocities and allow for sediment settling. This dispersion of sediments reduce turbidity of the water flowing downstream and enriches soils with nutrients.

Floodplains offer several recreational and educational opportunities for all to enjoy.

Several ecosystem services are offered by floodplains, including enrichment of biodiversity, flood mitigation, habitat provisioning, and water quality improvements.

Levees must be monitored and maintained to ensure structural stability. Timely and frequent maintenance is imperative and must be completed to ensure their functionality and prevent catastrophic failure.

Levees may protect communities immediately adjacent to the river from immediate flooding, however, the floodwaters are not eliminated. Instead, they are pushed further downstream and can lead to impacts downstream and further stress on other levees or infrastructure downriver.

Levees are typically installed to prevent flooding in the neighboring communities to the river. However, they tend to ‘squeeze’ the flow of the river by decreasing the cross-section width of the river. This flood restriction effect can increase flood durations and the risks associated with dangerous floods.

Levees block and disconnect rivers from their natural floodplains, which negatively affect the floodplain ecosystem and the various functions they provide. With installed levees, adjacent floodplains no longer receive the vital floodwaters that control and enhance their functions

Levees are heavily relied upon by adjacent communities to protect them from flooding during storm events. When a levee fails and is either overtopped or undermined, dangerous impacts can occur including severe damage to communities and infrastructure.

Constructed levees narrow a river channel and increase water velocities through its cross section. Faster water velocities through the river channel can increase erosion and impact in-stream vegetation.