DRAFT WATERSHED PLAN - ENVIRONMENTAL IMPACT STATEMENT (EIS) UPPER MAPLE RIVER WATERSHED, SITE 2A

The purpose of the proposed action is watershed protection.

The Upper Maple River watershed annually contributes 30,200 pounds of phosphorus and 331,600 pounds of nitrogen to the Red River, for which U.S. agreed to nutrient objectives at the international border have not been achieved.  Dissolved inorganic phosphorus is of particular concern, given that annual loads and concentrations have been on an upward trend since the early 1980s.  Average annual cropland inundation by flooding in the watershed is 12,600 acres which results in high transport of nutrients to the Maple River, in addition to detrimental impacts to agricultural production and infrastructure.  Historic loss of wetland and upland habitat throughout the Red River Basin, including the Upper Maple River watershed, threaten multiple species. 

The proposed action includes the construction of a multi-purpose dry dam with incorporated features to reduce nutrient delivery from the upstream watershed; reduce the extents, frequency, and duration of downstream cropland flooding to further reduce nutrient transport to the river; and to restore, enhance and create wetland and upland wildlife habitat. Upper Maple Site 2A will entail construction of a 2.3-mile earthen embankment dam, associated spillways, farmstead levees, and road raises.  Within the interior of the dry dam, the project will develop 264 acres of shallow water biomass harvest areas managed to optimize nutrient removal. The proposed action will result in a net gain of 124 acres of wetlands. Ultimately, the project will improve wildlife habitat with a 1,036 acre complex of wetlands (483 ac.) and upland habitat (553 ac.).  

Total Installation Cost:               $14,810,000

Federal (NRCS) Contribution:   $8,046,000

Current Status

NRCS published a Notice of Intent to prepare an EIS to the Federal Register on June 21, 2023.  Comments received from the scoping period were addressed in the revised Draft Plan-EIS. The Draft Plan-EIS was submitted for review to the National Watershed Management Center (NWMC) in March 2025. Following the edits, the revised plan will be sent to the NRCS National Headquarters for review. The final Draft Plan-EIS is expected to be completed in late summer 2025; the plan will then be presented at a public meeting as well as distributed for agency and tribal comments.  Section 106 consultation was completed on January 27, 2025.

More information: https://www.casscountynd.gov/government/water-resources-board/cass-county-joint-water-resource-district