9700

• UCREFRP Catalog Number: 9700
• Author: Hayes, J.W., K.E. LaGory and G.L. Burton.
• Title: Consideration of site-specific floodplain inundation thresholds in implementing peak flow magnitude and duration recommendations in the middle Green River, Utah.
• USFW Year: 2005.
• USFW - Doc Type: Argonne National Labortory, Argonne, Illinois.
• Copyright Material: NO

Green River Floodplain Inundation

June 2005

CONTENTS

ABSTRACT.................................................................................................................................... v

1 INTR.ODUCTION .................................................................................................................... 1

2 EXISTING PEAK FLOW RECOMMENDATIONS ..............................................................3

3 SITE-SPECIFIC FLOODPLAIN INFORMATION ................................................................ 7

4 IMPLICATIONS OF FLOODPLAIN CHARACTERISTICS ON PEAK-FLOW
RECOMMENDA nONS AND IMPLEMENT AnON ......................................................... 13

4.1 Timing and Duration of Connection to the Main Channel............................................ 13
4.2 Frequency of Connection to the Main Channel.............................................................14

4.3 Area of Inundation....... ........... ....... ............................. ................... ................................ 15

5 PROPOSED PEAK FLOW MANAGEMENT STRATEGy................................................ 17

6 UNCERTAINTIES ................................................................................................................21

7 REFERENCES ............. .... ........ ............. .............. ........... ........ ...... ....................... .......... ......... 23

FIGURES

1 Relationship between Flow and Total Floodplain Habitat Inundation in Reaches 2 and

3 of the Green River ............................. ................................ ............... ............................... ...... 6

2 Diagrammatic Representation of Depression and Terrace Floodplain Habitats...................... 8

3 Priority Floodplain Areas in the Middle Green River............................................................ 10

4 The Relationship between Flow and Area ofInundated Priority Depression Floodplain
Habitat and the Probability of Exceedance for Flows under Historic Regulated

Conditions ................................ ........... ........ ......................... .............. .................................... 14

5 Cumulative Area of Priority Depression Floodplain in Relationship to Distance
Downstream of the Razorback Spawning Bar ....................................................................... 16

6 Hypothetical Example of Flows at the Jensen Gage Under the Muth et al. (2000) Flow
Recommendations (527 m3/s [18,600 cfs] Connection Flow Target) and Alternative
Flow Management Strategies with Extended Duration Connection Flow Levels of 368
m3/s (13,000 cfs), 396 m3/s (14,000 cfs), and 424 m3/s (15,000 cfs)................................... 19

III