FLOOD03324

• County: Logan
• Community: Sterling
• Stream Name: Pawnee Creek
• Basin: South Platte
• Title: Flood Hazard Mitigation Feasibility Study
• Date: 3/1/2001
• Prepared For: Logan County
• Prepared By: ICON Engineering, Inc.
• Floodplain - Doc Type: Project

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HWY 6 and the BNRR/UPRR embankmellts arc major obstruction>, which divert Pa"'1lCC Creek flood
f1()W~ from the main channel towards the City of Sterling. The Town [If Atwood is located near the
natural tloodplaio of Pawnee Cred..; how","er. the City ,)f Stt;rling is [lot 'n,t; flood flu",> from
l>a'^'Tl~~ Creek into Sterling are mainly due to the manmadc embankments, which act as diversion
structllres.sillcC flood flov,'Son Pawnee Creek arc ootentircly ahlc to pass directly 10 Ihc South Platte
River through the existing hridgcs or over the embankments. When t1o"~ are high enough. a portion
of the flow is diverted to Sterling along the northwest side of the highway and railroad embankments.
This situation is known as the "Pawnee Overflow", Reference is made to Figure 2. which presents a
vicinity map of the area.

Cily of Sterling Contacts:

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Mayor
City Manager
Director of Public Works

l3illFineh
Randy Gl!stafson
JncKiolbasa

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City of Sterling
421 North4h.Street
130:'\4000
St~rling,COlW751
Phone: [phone]
Fax: (<J70) 521-0632

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I'ROJECT SF:RVIO: AI-lEA

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Study Ar~.a

The project .area is located in norrhea<t<!m Colorado, The City of Sterling ;md the project i<rea Jre
wilhin Logan Counly. which is approximately 120 miles northe,"'l of Denver. The wJtershe<l of
interest is the Pawnee Creek Basin, which is within th~ South Platte River Basin. The basin is a left
bank tributary wilh its eontluence with the South Platte River located upslream of the City limits of
Sterling. Colorado. Major lribularies to Pawnee Creek include: Raymer Creek; South l'a""11ee Creck
wilh its tributary Wildh('rse Creek; North Pawnee Creek with its tributary Igo Creck; C:ollonwo<x1
Creek; Ilorsclail Creek; and Spring Cre~k. 11\csc cred,~ are ba"i~ally intermittent wilh running water
in the lower reaches.

Predominate topographic featuresoflhe b~sin include the Pawnee BUltes in the upper reachcs"rlhe
basin, The basin's drainage area is apptoximalely 645 "quarc mdes. Elcvalion~ in the basin range
from approximatdy 5,400 feet to 3,980 feet. Tile watershed is mainly native grass Wilh !c)Cali7..:d
rq.ivns A ~lllli>alcJ Jgricullure. Suil, <il"C preJumill.aLci) :"wm ~llJ d,~y 10"111>>. ""ith "Wldsl'''le. ~hJ:e
anJsihstolleolllcwppings_ HydroI0glccurvcllumocrsareinlherangcof77lo79withtheprimary
vegetall"" j,,'ing IWli\"<' mng" with some v..'lnI<"f wn"al lln~ a S1\1nltICllnl amount ollrng,lled cropland III
thc l"".cr pHrl "t"thc ha,in

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