Physical History of the Platte River in Nebraska

• Description: related to the Platte River Endangered Species Partnership ‎(aka Platte River Recovery Implementation Program or PRRIP)‎,
• State: NE
• State: CO
• State: WY
• Basin: South Platte
• Water Division: 1
• Date: 8/1/2000
• Author: Simon & Associates, Inc.
• Title: Physical History of the Platte River in Nebraska: Focusing Upon Flow, Sediment Transport, Geomorphology, and Vegetation
• Water Supply Pro - Doc Type: Report/Study

TABLE OF CONTENTS
1. Introduction ................................................ ..............................1
2. Description of the Platte River Basin ................................................ .............................. 2
2.1 Water Resources Development History . 5
2.1.1 Canal building ................................................ ............................... 5
2.1.2 Dam and reservoir construction... . •8
2.1.3 Trans -basin diversions ............. .14
2.1.4 Groundwater development .................................. ............................... 14
2.1.5 Summary of current water resources development conditions ........................14
2.2 Flow History ................................................ .............................:. 15
2.2.1 Annual flow ................................................. ............................... 15
2.2.2 Annual peak flow ............................................. ............................... 16
2.2.3 Seasonal pattern of daily flow ...................... ............................... . .....16
2.3 Groundwater History ................................................. ............................... 18
2.4 Sediment Supply and Transport History ......................... ............................... 19
2.4.1 Suspended load...... ............ 19
2.4.2 Bed - material load and grain size distribution ............ .........:....................: 19
2.4.3 Bed - material size gradation and spatial distribution....... . 20
2.4.4 Bedform size, pattern, and movement ....................... .............................20
2.4.5 Sediment trapping .............................................. .............................21
2.4.6 Pre- development sediment transport ....................... ............................... 22
2.5 Channel Geometry .................................................... ............................... 22
2.5.1 Total channel width ............................................ .............................22
2.5.2 Active (unvegetated) channel width ....................... ............................... 22
2.5.3 Wetted channel width ...................... .................... 23
2.5.4 Channel depth ................................................... .............................23
2.5.5 Islands ......................................................... ............................... 24
2.6 Woody Vegetation ................... .24
2.7 Summary of Pre - Development Conditions ....................... ............................... 27
3. Current Baseline Conditions .............................. .............................30
3.1 Current Level of Water Resource Development ........... .............................30
3.1.1 Canals ............................................................ .............................30
3.1.2 Dams and reservoirs ......................................... ............................... 30
3.2 Flow Characteristics ....................................... .............................30
3.2.1 Annual flow ......... ............................... 31
3.2.2 Peak flow ................................................ ............................... 31
3.2.3 Seasonal pattern of mean daily flow ....................... ............................... 32
3.2.4 Flow duration analysis ......................................... .............................32
3.2.5 Flood frequency analysis .................................... ...............................
3.3 Groundwater and Surface Water Interactions ............. .............................33
3.4 Sediment Transport and Supply ........................... .............................34
3.5 Channel Geometry ..................................................... ............................... 43
3.6 Woody Vegetation ....................................................... .............................43
3.7 Summary of Current Conditions ..................................... .............................43
3.8 Discussion of Current Trends of Channel Morphology and Vegetation .................. 45
4. Channel Processes and Causes of Change ............. .............................46
4.1 Resource Linkages .............................................. .............................46
4.1.1 Natural resource inputs .............................. .............................46
4.1.1.1 Water .............................................. .............................46
4.1.1.2 Sediment ...................................... ...............................
47
4.1.1.3 Vegetation ........................................ .............................47
4.1.2 Human actions ................................................ ...............................
4.1.2.1 Water resources development ............................ .............................47
47
4.1.2.2 Structures ......................................... .............................48