Conducting a virtual flood for Devils Lake, North Dakota

This paper describes the process of planning and conducting a Virtual Flood of Devils Lake, North Dakota. A Virtual Flood is a workshop in which interested parties can use computer simulations to test flood fighting measures. Devils Lake, a terminal lake located in North Dakota, has risen over 20 feet during the last four years. This increase in elevation has generated approximately $120 million in damages and mitigation efforts. In 1995, 1996 and 1997, the lake rose to levels hydrologists had said were possible, but improbable. Levees were built and then raised, and raised again. The St. Paul District of the US Army Corps of Engineers and the State of North Dakota are studying a plan to pump lake water into an adjacent river basin. The first analysis showed the costs for the pump were much greater than the benefits, but many distrusted the analysis because the economic benefits of the pumping plan were based on the estimate of probable future lake levels. The question in many peoples' minds was, if we were forecasting lake levels better, would the benefits exceed the costs? Late in 1997, the Corps, the state, and stakeholder groups agreed to participate in a Virtual Flood of Devils Lake. The goal of the Virtual Flood of Devils Lake, held on March 11, 1998 in Grand Forks, North Dakota, was to develop a common understanding among stakeholders and management agencies of the effectiveness of a proposed artificial outlet in reducing flood damages. The Virtual Flood demonstrated that the outlet would likely not reduce lake levels enough in the next several years to avoid other flood fighting costs, such as the construction of levees and road raises.