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City 101: Floodplains Explained

floodplain_imageYou’ve probably heard of floodplains, and may even live in or near one. But what exactly is it and how does it affect community development and where and what things can be built?

A floodplain is an area of low-lying ground adjacent to rivers, formed mainly of nutrient-rich river sediments and subject to flooding after storms and/or heavy snowmelt. A floodway is the portion of the floodplain that includes the channel of a river (or other flood sources) and the area likely to be flooded in a base flood. You might consider this the trough of the floodplain.

While virtually no development is allowed in a floodway, North Plains has 77 acres of floodplain within the 100-year floodplain of McKay Creek and its tributary Ghost Creek. The areas have varying restrictions for development depending on the zoning and severity of potential flooding as determined by the Federal Emergency Management Administration (FEMA).

The City works with FEMA and Washington County to regulate development and to periodically update the delineation of the floodplain to minimize risk, and to also enable residents to qualify for flood insurance. This community-based effort aims to prevent or reduce the risk of flooding and protect homeowners, resulting in a more resilient community.

You can view our community’s flood map and see the relationship between your property and the areas with the highest risk of flooding here: http://msc.fema.gov.

The City of North Plains has adopted a floodplain ordinance and enforces building codes that detail rules and requirements to protect people and property, reduce future flood losses, and make sure that federal flood insurance is available to property owners. In North Plains, the City handles straightforward permits for development within floodplains and works with Washington County on more complex applications.

It is important to keep in mind that while floodplains can create risk, they also greatly benefit the natural environment in various ways including fish and wildlife habitat protection, natural flood and erosion control, surface water quality maintenance, and recreational opportunities. So, get to know your local floodplain!