7806

• UCREFRP Catalog Number: 7806
• Author: U.S. Department of the Interior.
• Title: Quality of Water, Colorado River Basin.
• USFW Year: 1997.
• USFW - Doc Type: Progress Report No. 18,
• Copyright Material: NO

Contents-Continued

FIGURES

Figure Page

1 Map of Colorado River System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
2 Sources of salinity in the Colorado River Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3 Schem~tic of agricultural salt pickup ..................................... 9
4 Salinity costs by user group ...............................,.......... 14
5 Annual damages increase with salinity ................................... 15
6 Map of salinity control units and study areas .............................. 39
7 Schematic of salt pickup at Big Sandy River Unit . . . . . . . . . . . . . . . . . . . . . . . . . .. 50
8 Salt loading mechanism in Grand Valley Unit. . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 54
9 Schematic of Meeker Dome Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 64
10 Schematic of Paradox Valley Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
. 11 Selenium levels in the Colorado River Basin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
i2 Reservoir effects on salinity at Glen Canyon Dam . . . . . . . . . . . . . . . . . . . . . . . . . . . 77
13 Comparison of past and current depletion projections . . . . . . . . . . . . . . . . . . . . . . . .. 78
14 Lower mainstem flows (1970-95) ...................................... 78
15 Salinity in mainstem (1970-95) ........................................ 79
16 Natural variation in salinity at Imperial .................................. 81
17 Salinity adjusted to long-term mean flow conditions for comparison to the numeric
criteria of the salinity standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 83
18 Verification of CRSS salinity projections ................................. 84
19 Predicted salinity trends in the Lower Basin monitoring stations ................. 86
20 Illustration of wet and dry hydrologic sequences on salinity levels at Imperial Dam ... 90
A-I Colorado River water quality monitoring stations .......................... A-2

TABLES

Table Page

1 Comparison of ri ver basin drainage and runoff .............................. 7
2 Water use in the Colorado River Basin (1981-85 Average) . . . . . . . . . . . . . . . . . . . ., 11
3 Colorado River Basin depletion projections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 18
4 Cost-effectiveness summary (Reclamation) ................................ 50
5 Cost-effectiveness summary (USDA) .................................... 51
6 Effectiveness summary (BLM) ........................................ 51
7 Land retirement costs and cost effectiveness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 57
8 Selenium concentrations and loads in the Colorado River Basin ................. 71
9 Range of salinity conditions expected with full compliance with salinity standards .... 80
10 Comparison of salinity levels to the numeric criteria for the existing level of
development and salinity control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 82
11 Salinity control requirements and needs .................................. 85.
12 Statistical analysis of Hoover Dam salinity levels ........................... 87
13 Statistical analysis of Parker Dam salinity levels . . . . . . . . . . . . . . . . . . . . . . . . . . ., 88
14 Statistical analysis of Imperial Dam salinity levels. . . . . . . . . . . . . . . . . . . . . . . . . .. 88

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