Benefitting humans and the environment, floodwaters distribute nutrient-rich sediments to soil and vegetation and replenish streams and wetlands. A healthy floodplain stores and transports flood waters, which reduces flooding frequency, property damage, fatalities, erosion, and hazardous material releases into waterways.

Floodplain overlay districts can minimize impacts to water quality due to flooding and flood-related erosion by any of the following methods:

- Restricting or prohibiting uses that could threaten water quality

- Requiring water supply and sanitation systems to be protected against flood damage at the time of construction

- Delineating areas vulnerable to flooding to protect individuals from purchasing floodplain land not suitable for their purposes

- Regulating excavation, filling, dumping, dredging, and channelization that may increase flood damage

- Preventing or regulating the construction of flood barriers that unnaturally divert floodwater and increase velocity, turbidity, and water levels