############################################################## # UNITED STATES GEOLOGICAL SURVEY # # ******PROVISIONAL DATA SUBJECT TO REVISION****** # # # # NOTE: These data have not been reviewed or edited and may # # be subject to significant change. Data users are cautioned # # to consider carefully the provisional nature of the infor- # # mation before using it for decisions that concern personal # # or public safety or the conduct of business that involves # # substantial monetary or operational consequences. # # # ############################################################## Probability of future lake levels of Devils Lake, ND _________________________________________________________________ The following table gives possible future levels of Devils Lake along with the probability of exceeding those levels, given initial conditions existing in spring of 1998. The probabilities are computed based on 10,000 traces from a statistical water mass-balance model for Devils Lake, developed by the U.S. Geological Survey in cooperation with the North Dakota State Water Commission and the U.S. Army Corps of Engineers. For more information, see USGS Fact Sheet FS-158-95 which is included in the USGS Devils Lake Home Page. NOTE: The model simulations begin Apr 1, 1998, with an initial lake level of 1443.1 feet above sea level. The lake-level that is exceeded with a given probability may change depending on antecedent precipitation, lake levels, and inflows at the beginning of the simulation period. The magnitude of the change is largest during periods of extreme wet or dry conditions. Information in this table should not be used to forecast future lake behavior, because the limited temporal resolution of the model is not sufficient for short-term prediction. However, assuming stationary climatic conditions, the table can be used by water resource managers to determine the likelihood of future lake levels that may occur. ############################################################# # All lake levels in feet above mean sea level. Table last # # updated Apr.24, 1998. Rate of flow from Devils Lake to # # Stump Lake at various elevations is determined from data # # supplied by the ND State Water Commission (personal # # communication, Bruce Englehardt, NDSWC). Climate factors # # supplied by the Univ. of North Dakota Regional Weather # # Information Center (personal communication, Leon Osborne) # # are included in the simulations. These climate factors # # show generally above normal expected precipitation for # # 1998-2002. Estimated model parameters were revised in # # winter of 1997 to include precipitation, evaporation, and # # inflow data for 1950-96. The longer period of record # # used to fit the model and the inclusion of climate factors# # both resulted in an increase in the exceedance levels over# # those given previously. # ############################################################# __________________________________________________ Lake level for which probability of exceedance in given year is Year .2% 1% 5% 10% 50% __________________________________________________ 1998 1447.6 1446.7 1445.9 1445.5 1444.6 1999 1450.4 1448.7 1447.7 1446.8 1444.6 2000 1453.4 1449.6 1448.1 1447.4 1444.3 2001 1455.9 1451.3 1448.4 1447.7 1444.1 2002 1456.7 1452.5 1448.6 1447.7 1443.9 2003 1458.0 1452.9 1448.4 1447.6 1443.5 2004 1458.0 1453.0 1448.4 1447.3 1443.0 2005 1458.3 1452.9 1448.3 1447.1 1442.5 2006 1457.8 1452.7 1448.2 1447.0 1442.0 2007 1457.6 1452.5 1448.1 1446.8 1441.6 2008 1456.6 1452.3 1448.0 1446.6 1441.1 2009 1456.4 1452.1 1447.8 1446.4 1440.7 2010 1455.7 1452.0 1447.6 1446.2 1440.2 2015 1454.7 1450.3 1447.0 1445.1 1438.4 2020 1453.7 1449.9 1446.3 1444.4 1436.8 2025 1453.6 1450.0 1445.9 1443.8 1435.7 2030 1455.1 1449.9 1445.8 1443.4 1434.7 2035 1455.6 1449.5 1445.6 1443.2 1433.9 2040 1453.6 1449.7 1445.5 1442.9 1433.2 2045 1453.1 1449.5 1445.1 1442.7 1432.8