Mitigation and Adaptation Strategy: Protect and Enhance Floodplains, Wetlands, and Small Streams

Floodplains are nature's system for reducing the severity of floods. Floodplains are also critical open space and wildlife habitat since they are typically part of greenways along river and stream systems. Altered seasonal water flows may threaten flood plain functionality, which can adversely impact biological and nutrient cycles, and also seed dispersal. In addition, it may favor non-native over native species. Where the connections between floodplains and rivers have been severed, as by development, efforts should be made to reconnect them.

Wetlands and small streams provide flood storage capacity. They are also vital parts of our ecosystem, especially for many locally endangered species. They purify water and slow runoff from storm events. Moreover, they are also effectively sequestering and storing carbon. When wetlands are lost or degraded, significant quantities of carbon can be released into the atmosphere.

As stated by A. M. Nahlik and M. S. Fennessy (2016): "Soil carbon is vital in regulating climate, water supplies and biodiversity—all essential contributions to the provision of ecosystem services. Wetlands contain a disproportionate amount of the earth’s total soil carbon; holding between 20 and 30% of the estimated global soil carbon despite occupying 5-8% of its land surface. The anoxic conditions characteristic of wetland soils slow decomposition and lead to the accumulation of organic matter. As a result, wetlands can accumulate large carbon stores, making them an important sink for atmospheric carbon dioxide."

Ponds capture significant amounts of leaves and other organic debris. Similar to wetlands, anoxic conditions on the pond bottom slow decay and retain carbon. Ponds also temporarily store excess stormwater, reducing flows in streams and therefore down-gradient flooding.