Flood Damage Assessment and Survey of Mitigation Efforts at Stump Lake, North Dakota: A Study of a Closed-basin Lake Flood

The views expressed in this report are those of the authors and not necessarily those of the Natural Hazards Center or the University of Colorado. Since 1993, Devils Lake, a terminal lake in northeastern North Dakota, has risen 7.3 m in response to an unprecedented ten-year regional wet cycle. Lake area has nearly tripled, resulting in more than $400 million dollars in direct flood damages. Beginning in 1999 Devils Lake began to overflow into Stump Lake, a smaller closed lake sub-basin located in Nelson County. Outflow from Devils Lake has combined with local runoff to produce a 1.5-m rise in Stump Lake over the past three years. Extensive rural flooding marked by an increase in the number, size, and permanence of wetlands has also occurred within both lake basins over the same period. The authors document the flood history of Stump Lake and rural Nelson County, assess the flood damages resulting from the rise of Stump Lake and the growth of rural wetlands in Nelson County, and survey the flood mitigation efforts associated with this closed-basin flood hazard. Remote sensing image interpretation, field work, personal interviews and compilation of data from private, county, state, and federal agencies are used to quantify the direct, indirect, and secondary damages associated with terminal lake and rural wetland flooding in Nelson County. Results document the comparative magnitudes of direct, indirect, and secondary flood damages, as well as the relative contribution of rural wetland and terminal lake flood damages. The study provides a case history of a pervasive, chronic flood hazard not routinely addressed by federal flood mitigation programs