Location: Cavalier, Pembina, and Walsh Counties, North Dakota
Client: Park River Joint Water Resource District
The Park River Watershed encompasses approximately 990 square miles of the Red River Basin and primarily resides in Cavalier, Pembina, and Walsh counties. Of the river’s three contributing branches, the South and Middle branches are largely regulated through a series of impoundment structures. The North Branch, however—which encompasses 258 square miles—currently has no impoundment locations, resulting in substantial flood damages from both spring runoff and summer rainfall events.
In response to the 2013 spring flood event, where rapid snowmelt followed by severe spring rains resulted in substantial flood damages, the Walsh and Pembina County Water Resource Districts formed the Park River Joint Water Resource District (PRJWRD) to seek out and implement solutions to alleviate frequent flooding that occurs in the North Branch/Cart Creek tributary to the Park River.
HEI was retained by the PRJWRD to provide technical assistance in determining locally acceptable projects to reduce flood damages in the region.
Initially, HEI assisted the PRJWRD in developing a Purpose and Need Statement that outlined problems related to high flows and acceptable levels of risk for the region. HEI then began to explore different flood mitigation options within the watershed. After coordination with the PRJWRD and public engagement, a preferred alternative was determined and was evaluated in greater detail.
The preferred alternative consists of an impoundment site east of Mountain, ND, that diverts high flows from Cart Creek to the impoundment site. Cart Creek is a tributary to the North Branch Park River. The floodwater is stored to reduce downstream flooding impacts to agricultural land and to the city of Crystal, ND. The reduced flooding in the North Branch Park River Watershed will also help to improve soil health and water quality in the region.
After completion of the detailed hydrologic and hydraulic modeling of the preferred alternative, HEI completed an Environmental Assessment (EA) for the watershed. Various environmental aspects associated with the project were investigated as part of the EA including existing wetlands, soil resources, land use, and many others.
HEI continues to work with the PRJWRD and the National Resource Conservation Service to work towards the completion of the project.
The existing 500-year inundation.
- Reduce flood damages in the North Branch/Cart Creek Watershed.
- Provide flow reduction to the lower reaches of the Park River and the City of Grafton, ND.
- Lessen the Park River Watershed’s contribution to flooding along the Red River.