The Heart River
The Heart River originates in Billings County (western North Dakota) and empties into the Missouri River just south of Mandan, ND. Along the way, it flows through the valleys of Stark, Grant, and Morton Counties and into the heart of the City of Mandan. While typically flowing comfortably within its banks, it is susceptible to ice jams and associated flooding during spring runoff events. To combat this, the Lower Heart River Levee System was constructed in the 1940s and 1950s by the U.S. Army Corps of Engineers (USACE). The levee system is comprised of three segments: the Lower Unit, the North (Mandan) Unit, and the Sunny Unit. Over the years, levee improvements have been made, and it has served the City of Mandan well, providing protection from flooding events in 1950, 1952, 1997, 2009, 2019 and more.
The USACE inspects the levee system annually to assure it operates successfully to provide real and recognized flood protection to the City of Mandan and surrounding areas. Recently, the USACE and FEMA have determined the levee system to be out of compliance with federal levee safety standards. If the levee system is de-accredited by FEMA due to non-compliance, the USACE will not provide funding and technical assistance during a flood event. Non-compliance would also require property owners protected by the levee to be subject to flood insurance premium requirements. Levee improvements must be made in order to bring the levee system up to federal standards and maintain FEMA accreditation.
The Lower Heart River Water Resource District owns and operates the Lower Heart River Levee System and is responsible for making the required levee improvements and resolving issues that will ensure the levee system maintains FEMA accreditation and USACE compliance. The Lower Heart River Water Resource District is working with a consultant to design the levee improvements. This endeavor is being referred to as the Mandan Flood Risk Reduction Project.
