Publications on the Science of Healthy Rivers

Key to protecting Greater Yellowstone rivers is managing for these rivers’ natural values. Allowing rivers to access their floodplains provides immense ecological benefits. Floodplains store water, serve as natural sponges to moderate the release of high waters, and act as filters to trap sediments and pollutants. They reduce the velocity of the river during high waters. Periodic flooding rejuvenates and secures floodplain cottonwood forests and riparian vegetation, some of the region’s most diverse and threatened habitat, preventing bank erosion and offering shade which reduces unwelcome warm water temperatures and provides habitat for fish and wildlife.

Yet throughout the region, increasing numbers of property owners are altering the natural characteristics of the rivers along which they live in attempts to protect structures and prevent flooding. Poor land use decisions have put more homes, businesses and municipal buildings in harms way, leading to more efforts to control rivers and eliminate the natural flood control functions of floodplains. These changes lead to alteration of stream channels, loss of floodplain function, declines in fish populations and expensive flooding impacts.

New approaches to floodplain management are needed to retain natural floodplain function. These efforts would involve steering future development away from the floodplain to avoid additional demands to control the river, restoring riparian areas, and allowing rivers to flood. The placement of critical riparian lands in conservation easements and other partnerships with landowners and state and federal agencies to restore degraded riparian habitats could help achieve this goal. The permitting processes that promote river confinement must be changed to recognize the need for maintaining and restoring natural river function.

Floodplain Reports:

GYC has partnered with American Rivers to produce a study on the human and ecological impacts of building in the floodplain, along with the effects of various setback policies in 4 counties in Montana: Park, Sweetgrass, Yellowstone and Dawson Counties. You can view these reports here:

Floodplain Reports- Large files (pdf , about 2.5 MB each, good for printing out).

Floodplain Reports- Small files (pdf , about 600Kb each, suitable for viewing online)