Climatology, hydrology, and simulation of an emergency outlet, Devils Lake basin, North Dakota

Devils Lake is a natural lake in northeastern North Dakota that is the terminus of a nearly 4,000-square-mile subbasin in the Red River of the North Basin. The lake has not reached its natural spill elevation to the Sheyenne River (a tributary of the Red River of the North) in recorded history. However, geologic evidence indicates a spill occurred sometime within the last 1,800 years. From 1993 to 1999, Devils Lake rose 24.5 feet and, at the present (August 2000), is about 13 feet below the natural spill elevation. The recent lake-level rise has caused flood damages exceeding $300 million and triggered development of future flood-control options to prevent further infrastructure damage and reduce the risk of a potentially catastrophic uncontrolled spill. Construction of an emergency outlet from the west end of Devils Lake to the Sheyenne River is one floodcontrol option being considered. This report describes the climatologic and hydrologic causes of the recent lakelevel rise, provides information on the potential for continued lake-level rises during the next 15 years, and describes the potential effectiveness of an emergency outlet in reducing future lake levels and in reducing the risk of an uncontrolled spill. The potential effects of an outlet on downstream water quantity and quality in the upper Sheyenne River also are described. Introduction The Devils Lake Basin is a 3,810square-mile (mi2) subbasin (fig. 1) in the Red River of the North Basin. About 3,320 mi2 of the total 3,810 mi2 is tributary to Devils Lake; the remainder is tributary to Stump Lake. At an elevation of 1,446.5 feet (ft) above sea level (asl), Devils Lake begins to spill into Stump Lake; and at an elevation of about 1,459 ft asl, the combined lakes begin to spill through Tolna Coulee into the Sheyenne River (fig. 2). Since the end of glaciation about 10,000 years ago, Devils Lake has fluctuated from about 1,459 ft asl, the current natural spill elevation of the lake to the Sheyenne River, to about 1,400 ft asl. Although no documented records of lake levels are available before 1867, Upham (1895, p. 595), on the basis of tree-ring chronology, indicated the lake level was 1,441 ft asl in 1830. Lake levels were recorded sporadically from 1867 to 1901 when the U.S. Geological Survey (USGS) established a gaging station on Devils Lake. From 1867 to the present (August 2000), the lake level has fluctuated between a maximum of 1,447.1 ft asl in 1999 and a minimum of 1,400.9 ft asl in 1940 (fig. 3). The lake rose 24.5 ft from February 1993 to August 1999, and on August 1, 2000, the lake level was 1,446.1 ft asl. The original survey of the Stump Lake area was conducted between 1881 and 1883. At that time, Stump Lake was between 1,420 and 1,425 ft asl, about 10 to 15 ft higher than its August 1, 2000, level of 1,409.8 ft asl. When Devils Lake peaked at 1,447.1 ft asl in the summer of 1999, water was just beginning to trickle into Stump Lake. Therefore, considering its small drainage area, for Stump Lake to be above 1,420 ft asl between 1881 and 1883, a substantial amount of water probably flowed from Devils Lake into Stump Lake sometime before 1880. Joseph Nicollet, who explored the Devils Lake area in 1839, described the area between Devils Lake and Stump Lake as big deep coulees (Bray and Bray, 1976). Nicollet stated “These are dry at the moment but in time of high water seem to receive water from Devil’s Lake. ” This information indicates water flowed from Devils Lake to Stump Lake sometime between 1820 and 1840. Radiocarbon dating of organic matter such as wood, bone, or plant matter found in buried soils or beaches was used to provide an understanding of lake-level fluctuations of Devils Lake before the early 1800’s. In 1987 and 1997, North Dakota State Geological Survey geologists collected samples from beaches along Devils Lake and from sediments in the Jerusalem outlet for radiocarbon year to year. The jet stream, which is a ribbon of high-velocity air located about 30,000 ft above the Earth’s surface, exists because of temperature differences between air masses at the Earth's poles and at the equator. The movement of weather systems along the jet stream determines the distribution of precipitation about the globe. Climate variability results from a longterm shift in circulation patterns of the jet stream. As the circulation patterns shift, precipitation and temperature patterns also shift. Devils Lake has an enhanced sensitivity to long-term shifts in global circulation patterns as the level of the lake depends on many years of antecedent precipitation, runoff, and evaporation. If at any time precipitation, runoff, or evaporation is dominant, a corresponding dramatic response occurs in the lake level. Global atmospheric circulation patterns are driven predominantly by variations in sea-surface temperatures. The most noticeable of these variations, known as El Nino, occurs in the equatorial Pacific and accounts for the dramatic variations in precipitation patterns along the western equatorial regions of South America. Across the plains of the northern United States and southern Canada, El Nino and its cold counterpart--La Nina--produce variations in precipitation and temperature patterns primarily in the winter months (Montroy, 1997). However, long-term variations in annual precipitation and temperature patterns across the region also occur as a result of variations in the tropical sea-surface temperatures. These long1,480