FLOOD03288

• County: Morgan
• Community: Wiggins
• Stream Name: Kiowa Creek
• Basin: South Platte
• Title: Kiowa Creek at Wiggins Flood Warning System
• Date: 9/1/1990
• Prepared For: Wiggins
• Prepared By: US Army Corps of Engineers
• Floodplain - Doc Type: Floodplain Report/Masterplan

provided by the CWCB for KimTa. Creek at Wiggins, was used to
analyze the effect of flooding on Rock CrE~ek and Kiowa Creek
downstream of the County Road Gage.
For the purpose of analysis:, the l.orst case scenario was
assumed. This scenario included a (~onstant discharge of 749
cfs on Kiowa Creek at the county Road GagE~; a flow just below
the amount required to trig~re'r the flood alarm. storms of
10, 50, 100 and 500-year frelquency were then centered over
Rock Creek and the portion of' the Kiowa Creek Basin between
the downstream 'gage and Wiggins. Appropriate depth area re-
ductions were made to the point rainfall values for the
smaller watershed. Table 7 presents the discharges produced
at the Burlington Northern closure structure under this sce-
nario. A discharge-frequency table for a basin-wide storm
over the Kiowa Creek watershed, is shown in Table A-Ion Page
29.

~~A,BLE 7.
FLOOD FREQUENCY DISTRIEiUl'ION FOR ROCK CREEK AND
LOWER KIOWA, CREEK BASIN
(Dischcu'ges in cfs)

FLOOD FREQ.
la-YEAR
50-YEAR
lOa-YEAR
500-YEAR

ROCK CREEK
930
2,430
3,310
5,510

UPSTREAH Q.
749
749
749
749

PEAK AT WIGGINS
1,680
3,180
4,060
6,260

From the rating curves developed at the closure structures,
it is evident that a discharge expected once in 500 years,
from Rock Creek and the lowelr Kiowa Creek Basin alone, is
much below the discharge needeld to enter Wiggins through the
Highway 6 or Burlington Nor1:hern Closure structures (23,100
cfs or 33,000 cfs, rE!specti vely) .

4. AUTOMATED FLOOD DETECTION EQUIPHENT AND INSTALLATION

4.1 Selection of Equipment
The following discussion of the flood warning system compo-
nents makes reference to spE!cific equipmEmt brands and ven-
dors. There may be other commercially available components
that could be used as substit:ut.es for the equipment listed.
Presently, we are unaware of other SOUrCE~S of float switches
or 2-channel alarm dialers and could not provide technical
assistance regarding the opera.tion of equipment, other than
those noted in this report.

4.2 Description of Device and Basic Opera1:ion
4.2.1 Background
The flood detection device present,~d in this report was de-
veloped by the Omaha District:, U. S. Army Corps of Engineers
in 1989. The devices are currently in use in 3 flood warning

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