FLOOD02718

• County: Logan
• Community: Logan County
• Stream Name: South Platte River, Pawnee Creek
• Basin: South Platte
• Title: Floodplain Information South Platte, Pawnee
• Date: 9/1/1978
• Prepared For: Logan County
• Prepared By: US Army Corps of Engineers
• Floodplain - Doc Type: Floodplain Report/Masterplan

26

FUTURE FLOODS

rn
o

Floods of the same or I~rger magnitude than those that
have occurred could occur In the future. To determine the flood
potential of the study area, the 10-yeal", 50-year. 100-yelll", and
500-yeal" floods were analyzed. The results of this analysis are
presented In this report as a means of demonstrating the effects
of large floods.

c
.
.
rn
.
.
,
"
.
,
"
,

Discharge magnitudes for floods on the South Platte
River analyzed In this report were based upon date collected at
U.S. Geologica! Survey Stream Gaging Stations located at Denver,
Henderson, Kersey. Weldona, ~Izec, and Julesburg all in Colorado.
Discharge values developod at SterlIng were part of an overall
South Platte RIver study. P"ak dIscharge probabIlity relatlon-
ships were developed from these records. A b~sln model ~~s devel-
oped to determine dIscharge probabIlIty relationships for locations
other than at the stream gage locations.

,
"
"
o
.
c
.
3

.
"
.
.
o
>
.
o
"
>
.
"
. '
rn
0<
- .

DIscharge magnitudes for Pa~nee Creek floods studied In
this re~rt ~ere developed using the MassaChusetts Institute of
Technology Catchment Model (MITCATl. The Pawnee Creek basin ~aS
divided Into 50 subbasins. Rainfall data utilized ~aS derIved from

U.S. Woather Bureau TOChnica! Papor ~b. 40. ~~xlmum 3-hour rnln-
fall values used for the 10-year, 50-year, 100-year, and 500-year
floods are 1.55, 2.28, 2.50, and 3.32 Inches, respectively. An
Infiltration rate of 0.60 Inches per hour ~as used. The standard
dovlatlon ostlmated for Pa~nee Creek by the MITCAT model compared
favorably ~Ith that determined in an adjacent basin having stream
gagedllta.

rn
00
_ 0
""
8"
_0
.N

.
.
c
"
.
.

"