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completed in August 1976, November 1976, March 1977, and April 1979, respectively. For the unincorporated areas of Adams County, approximate flood boundaries for standing bodies of water greater than 25 acres were arbitrarily determined in February 1977, by Dames & Moore, under contract to the FIA. The Adams County study was revised on December 15, 1989, to modify the Special Flood Hazard Areas (SFHAs) along a reach of the South Platte River, approximately 2.3 miles long. The revised reach extended from a point approximately 760 feet downstream of the westbound lane of Interstate Highway 270, upstream to the south boundary of Adams County, at the City and County of Denver corporate limits (Franklin Street). The basis for the 1989 reV'Slon lS revised hydraulic analyses conducted by Wright Water Engineers, Inc., Denver, Colorado, under contract to the Urban Drainage and Flood Control District (UDFCD). The revised hydraulic analyses utilized the U.S. Army Corps of Engineers (USACE) HEC-2 hydraulic computer model and were conducted in August 1986 and September 1987. The hydraulic reanalyses modified the lOO- and 500-year flood boundaries and increased the base (lOO-year) flood elevations (BFEs) along portions of the South Platte River by up to 5 feet. Additional hydraulic analyses within the City of Commerce City were completed by Simons, Li and Associates, Inc., in June 1987, to reflect channel modifications for a reach of Sand Creek between Vasquez and Brighton Boulevards. Revised hydraulic analyses were also conducted for a reach of the South Platte River, from approximately 760 feet downstream of westbound Interstate Highway 270 to the upstream corporate limits of Commerce City at Franklin Street, by Wright Water Engineers, Inc., under contract to the UDFCD. The hydraulic reanalyses for the reach of the South Platte River through Commerce City were completed in September 1987. The hydrologic and hydraulic analyses for detai led areas in the Town of Federal Heights were performed by Greiner Engineering Sciences, Inc., for the Federal Emergency Management Agency (FEMA) , under Contract No. EMW-83-C-ll73. This study was completed in July 1984. Additional approximate analyses in this study were performed by the Colorado Water Conservation Board (CWCB) (Reference l). This revision has combined the Flood Insurance Rate Maps and Flood Insurance Study reports of the County and incorporated cities into the countywide format~ Under the countywide format, Flood Insurance Rate Map panels have been produced using a single layout format for the entire area within the county instead of separate layout formats for each community. The single layout format facilitates the matching of 2