FLOOD05745

• County: Crowley
• Community: Ordway
• Basin: Arkansas
• Title: Floodplain Study
• Date: 6/1/1987
• Prepared For: Ordway
• Prepared By: Simons Li & Associates Inc.
• Floodplain - Doc Type: Floodplain Report/Masterplan

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5

II. HYDROLOGIC ANALYSIS
A hydrologic analysis was conducted to determine the peak rate of flow
and volume of floods produced by rainfall in the Town of Ordway. The modeling
of such a flood event required that the drainage basins affecting the Town and
surrounding areas be divided into two categories. These were: (1) the three
offsite basins which lie north, northeast, and northwest of the Town, and (2)
the drainage basins lying within the Town 1 imits. This was done because of
the need to apply hydrologic methods which are best suited to agricultural
areas drained by "natural" drainageways, and to apply another method best
suited for tile urbanized area which is drained by a street and storm sewer
system.

General Basin Characteristics
C1 imate
This area of Crowley County has a temperate, semiarid climate that is
typical of the Arkansas River Valley. Days are hot during July and August,
but except for July and August, nights are cool in summer. In winter, which
is cold, the Vlind is considerable and blows the snow, but warm chinook winds
occur occasionally. The growing season is about 160 days, and the mean annual
temperature is about 520 F.
The amount of preci pi tati on va ri es from year to year, and comes mos t1y as
rain during April, May, June, and July. The annual average precipitation is
12 inches.
Wind has influenced soil formation by removing soil material from one
place and depositing it in another. The effect of the wind can be seen in the
pattern of soil areas shown on the soil map in the Crowley County Soil Survey.
Long, narrow soil areas that trend southeast are di stinct and were formed by
winds blowing from the northwest. The pattern of surface drainage that was
cut by runoff water follows a southeasterly direction.

Soil s
Soils within the study area are clays and loamy clays, generally
classified as the Ordway and Limon Clay Series (Reference 1). The Limon
series consists of deep, poorly-drained 10am1y clays and clays. These soils
are nearly level to moderately sloping, take in water slowly to very slowly,