Channel Migration Zone Reports
The Sun River is highly migratory and over the years, has changed the face of the watershed landscape in big ways.
For this reason, SRWG has partnered with the Cascade Conservation District and the Lewis & Clark Conservation District to create Channel Migration Zone (CMZ) maps and reports. Completed reports can be found on the Resources page of this website. These reports are publicly available because we think they are important planning tools and we hope our landowners and other partners will consult them when making decisions about land use and infrastructure.
Infrastructure damage and loss as a result of Sun River migration
Phase I CMZ Report
SRWG partnered with Cascade Conservation District to hire a consulting team to create Phase I of the CMZ. This report looked at historic channel movement on the main Sun River from just upstream of the 287 bridge through Muddy Creek. Some reaches are pretty stable but some have historically moved quite a bit. Additional studies are needed in the high-risk reaches to make long-term recommendations. This study, completed in June of 2020, was funded by grants from DNRC’s 223 program and DEQ’s 319 program. Click the button below to view the report.
Effects of flooding on Elk Creek
Phase II CMZ Report
Phase II of the CMZ, made possible through a partnership with Lewis & Clark Conservation District, is focused on the movements of Elk Creek from its confluence with Smith Creek to where it meets the Sun River. This area is dramatically affected by flooding. The study will help landowners understand stream behavior and plan land use and infrastructure accordingly. The draft report will be presented for comment at a public meeting April 30 at the Augusta Youth Center. The Phase II Report was funding by a grant from DNRC’s 223 program.
The Sun River Watershed isn’t the only river where channel migration is an issue. Montana Aquatic Resources (MARS) has more information about channel migration available on their website.