Special Flood Hazard Study
ARMY ENGINEER DISTRICT SACRAMENTO CA
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In January 1997, the State of Utah endorsed the request from the city of Nephi which requested that the Sacramento District Corps of Engineers study the flood hazards associated with Biglows and Miller Canyons to the southeast of the city of Nephi. The current Flood Insurance Rate Maps show only the flood plain for Salt Creek just east of Nephi. This study is intended to provide flood plain information resulting from a detailed hydraulic model of Biglows and Miller Canyons. This study was approved and funded under the Corps of Engineers Flood Plain Management Services program. The city of Nephi, a community of approximately 1.5 square miles, is located at about 5,200 feet elevation on the northwest side of the San Pitch Mountains of central Utah, about 80 miles south of Salt Lake city in Juab County. The center of town is located on the alluvial fan formed by Salt Creek, which flows westward from the San Pitch Mountains. To the south of Salt Creek, Miller and Biglows Canyon Creeks discharge from steep canyons east of Nephi and pass through debris basins on alluvial fans, and flow west via small channels past Highway Interstate 15I-15 to West Creek. The Miller, Biglows and Hwy-15 Watersheds cover approximately 5.1 square miles of land on the west side of San Pitch Mountains. The study area lies to the southeast of the city of Nephi and extends from the canyon mouth to downstream of 1-15, a distance of about 5,000 feet on each creek. The study area is moderately developed rural farm lands. Topographic data was obtained from USGS 7.5-min Digital Elevation Models DEMs. These DEM data are stored as profiles with 30-meter spacing along and between each profile. At the same time, USGS 7.5-minute quadrangles were used as background for drainage basin and flood plain boundaries. Culvert and channel information were obtained by measurements in the field by study personnel.
- Hydrology, Limnology and Potamology