FLOOD00927

• Designation Number: 216
• County: Logan
• Community: Sterling
• Stream Name: Sand Creek and Pawnee Creek Overflow
• Title: Floodplain Information and Drainage Plan - Sand Creek and Pawnee Creek Overflow
• Date: 5/1/1983
• Designation Date: 7/1/1983
• Floodplain - Doc Type: Floodplain Report/Masterplan

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TABLE OF CONTENTS

Page
SYNOPSIS-------...-----------------.----.---------------------------- i

i.

LIST OF TABLES-------------------------------------------------------
LIST OF FIGURES------------------------------------------------------

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I. INTRODUCTION-------------------------------------------------- 1

Purpose and Scope--------------------------------------------- 1
Authorization------------------------------------------------- 2
Acknowledgements----------------------------------------------- 3
Report Acquisltion--------------------------------------------- 3
Related Studies---------------------.-.----------------------.- 3
Mapping and Surveying-------------.-------------------.--....-. 4
II. FLOOD HISTORY----.-----.------------------.-..----------------- 5
III.BASIN CHARACTERISTICS AND HYDROLOGy------..-------------------- 12
Pawnee Creek-----------------------------.--------------------- 12
Sand Creek Watersheds------.---------------.------------------- 12
Discharge Profiles.------.------------------------------------- 14
Irrigation Ditches-------------------..-------------------.---- 17
IV. HYDRAULIC ANALYSTS------.-------.--------.-.-.----------------- 18
Results----.---.------------.-....---.-------------.-.-.....--. 18
V. FLOOD PLAIN INFORMATION---------------..-----------.---.-.--... 29

5-,10-.25-. and 50-year Events..--------------------...-------. 29
100-year Event.------------------------------------------------ 29
500-year Event-------------------------------------------.----- 29
Extent of Flooding Under Existing COnditions-------.-.----.---- 30
FlOOd Insurance----------------------------------------------.. 30
VI. REFERENCES----------------------------------------------------- S2

LIST OF TJ\8lES

Paq~
Discharge Profiles for Pawnee Overflow-------------------- 15

Discharge Profiles for Sand Creek Flood--------.--.------- 16
Flood Frequency Elevation and Disch<lrge Data
Pioneer Drainage Ditch Profile Sterling. Colorado--------- Ig
F1oodFrequency--ElevationandDischargeOata
Sand Creek and local Drainage Profile Sterling, Co10.---u- 20
F10odFrequency--ElevationandOischargeOata
Pawnee Creek Overflow Profile Sterling. Co1orado-----------21

Permanent Reference Monuments------------------------------ 51