All streams and rivers are subject to flooding.  In mountainous areas, it’s typically annual spring flooding.  But other regions experience heavy rain events at other times of the year that can very quickly turn a peaceful stream into a raging torrent.  At THI we often help prospective landowners determine if buildings are in jeopardy, or help landowners make decisions about where to site homes and other improvements.

Before you build in or very near a floodplain, please consider the following: A stream or river is constantly adjusting itself. This is nature’s balancing act between the amount of water and gradient in the channel, and the amount and size of the sediment within the system. Any disturbance, either natural or human-caused, will change this balance. Activities such as building within the floodplain, constructing roads in riparian areas, or removing vegetation can limit a stream’s ability to maintain a healthy balance.

Residential or commercial construction within the floodplain does have an impact, as does protecting property by constructing dikes, levees, installing riprap, or eliminating overflows into side channels. The effects of these impacts within the floodplain can include increased peak flood levels, increased energy during a flood event downstream, increased bank and bed erosion on neighboring property, reduced habitat and reduced recreational values.

To limit or eliminate these impacts, avoid construction in the floodplain where possible; do not restrict floodwater access to side channels; and ensure construction within the floodplain minimizes disturbance of soils and vegetation.  Contact THI to Learn More or Request a Free Report Titled: Building Near Streams or Rivers.