FLOOD06226

• County: Weld
• Community: Fort Lupton
• Basin: South Platte
• Title: FIS - Fort Lupton
• Date: 10/1/1978
• Prepared For: Fort Lupton
• Prepared By: FEMA
• Floodplain - Doc Type: Current FEMA Regulatory Floodplain Information

Floods cauaedby overflow of the South Platte River were studied in
detail. The South Platte River is the only flooding source which
threatens the Town of Fort Lupton.

Those areas studied by detailed methods were chosen with consideration
given to all proposed construction and forecasted development
through 1982.

2.2 Community Description

The Town of Fort Lupton is located in southwestern Weld County, in
northeastern Colorado, and is surrounded by unincorporated portions
of Weld County. The 1970 population of Fort Lupton was 2489 (Refer-
ence 1), and grew to an estimated 1975 population of 3100 (Refer-
ence 2).

The flood plain in Fort Lupton is mostly either undeveloped or used
for agricultural purposes, although scattered commercial and resi-
dential developments do exist. The South Platte River flows northward,
past the western side of Fort Lupton. The South Platte River basin
is bounded on the west by the Continental Divide and the Rocky
Mountain Range, on the north by the North Platte River basin, on the
east by the Platte River basin, on the southwest by the Republican
River basin, and on the south by the. Arkansas River basin. Approxi-
mately 23 percent of the drainage area is in high mountainous
terrain in the Rocky Mountain Range. Dasin elevations range from
14,200 feet at the Continental Divide to 2,800 feet at the mouth of
the South Platte River (Reference 3).

The climate in the basin varies with its physiographic featureSe
Precipitation in the plains region, where Fort Lupton is situated,
averages 13.2 inches a year. The mean annual temperature is 480F,
with monthly averages ranging from 270F in January to 720F in July
(Reference 4).

2.3 Principal Flood Problems

Flooding on the South Platte River results from either intense
localized rainfall or general rains, and may be augmented by snowmelt.
Recent floods of this type occurred near Fort Lupton in 1942, 1948,
1949, 1965, 1969, and 1973. No damage estimates or flood frequencies
are available for Fort Lupton. The extent of flooding along State
Highway 52 can be seen in Figure 2.

2.4 Flood Protection Measures

A number of levees along the South Platte River protect adjacent
lands from low-frequency floods. A number of storage reservoirs in
the upper reaches of the South Platte River and its tributaries help
reduce the peak discharge during flood periods. Fort Lupton has not
undertaken any flood plain management.

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