Case Study

Swan River National Wildlife Refuge Wetland Restoration Project

The Swan River valley, in Montana, is nestled between the Swan Range to the east and the Mission Mountains to the west. The Swan River National Wildlife Refuge, managed by the US Fish and Wildlife Service and covering approximately 1,568 acres, consists of wetland/grassland habitat and deciduous and coniferous forests. Dense stands of reed canary grass are mixed with native reeds and sedges.

Large wetland drainage ditch with original ditch spoil material berm on right, and invasive reed canary grass on left


River Design Group (RDG), headquartered in Whitefish, Montana, is a private river and wetland restoration engineering firm specializing in ecological restoration for the benefit of fish and wildlife communities.


The Swan River National Wildlife Refuge faced several challenges that necessitated a wetland restoration project:


To address these challenges, the US Fish and Wildlife Service initiated a comprehensive wetland restoration project and retained RDG to analyze existing conditions, provide restoration alternatives and design and engineering, and oversee project construction. Geographic Information System (GIS) tools provided valuable insights into elevation differences, ditch slopes, and material volume calculations, guiding the efforts to restore fish habitat and wetlands. The key components of the solution included the following:

GIS Analyst standing on ditch spoil material berm, performing ditch bathymetry surveys which will be incorporated into the LiDAR surface in GIS for volume calculations
3-D view of bare earth LiDAR data model in GIS, showcasing historical wetland drainage ditch and berm at southern portion of Refuge
Preliminary north ditch fill design plansheet, showing access routes, strategic fill placement, and earthwork relocation


The wetland restoration project yielded several positive results:

North ditch fill design plansheet, showing berm/levee excavation, ditch fill locations, access routes, and materials quantities
Post-restoration condition of a historically ditched, abandoned oxbow meander of Swan River, with drainage ditch plugged and full inundation of wetlands

Future Considerations

River Design Group will perform follow-up drone flights as needed. In year three and year five of the project, the team will be completing follow-up wetland delineations as required by Army Corps of Engineers regulations.

In summary, the wetland restoration project successfully addressed the challenges of invasive-species dominance and historical land-use practices. By strategically filling drainage ditches and increasing groundwater levels, the project aimed to restore the wetland ecosystem, benefiting both wildlife and public use of the area. The comprehensive approach, including GIS analysis, groundwater modeling, and vegetation assessment, informed decision-making and contributed to the project’s success. The wetland restoration project is projected to restore wetland hydrology to 655 acres of previously drained wetlands and decrease reed canary grass dominance in favor of native wetland plant species.

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About the author

Esri AEC

The AEC Team, part of Esri's Industry Solutions marketing department, shares GIS news, trends, and technology updates for architecture, engineering, construction, environmental consulting and survey professionals in multiple industries. The team works with colleagues across Esri divisions (solutions, professional services, product and more) to provide the best support for our customers and partners.


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