Hydrology of the L.C. Holding coal-lease tract and adjacent areas, southwestern Utah, and potential effects of coal mining

100 Pages·1991·4.9 MB·English

by  Cordy, G.E., Seiler, R.L.

Hydrology of the L.C. Holding coal-lease
and adjacent areas, southwestern
tract
mining
Utah, and potential effects of coal
GEOLOGICAL SURVEY
U.S.
Water-Resources Investigations Report 91-4111
Digitized by the Internet Archive
in 2012 with funding from
LYRASIS Members and Sloan Foundation
http://archive.org/details/hydrologyoflcholOOcord
1
HYDROLOGY OF THE HOLDING COAL-LEASE TRACT
L.C.
AND ADJACENT AREAS, SOUTHWESTERN UTAH, AND
POTENTIAL EFFECTS OF COAL MINING
By G.E. Cordy, R.L. Seiler, and B.J. Stolp
GEOLOGICAL SURVEY
U.S.
Water-Resources Investigations Report 91-411
Prepared in cooperation with the
BUREAU OF LAND MANAGEMENT
U.S.
Salt Lake City, Utah
1993
U.S. DEPARTMENT OF THE INTERIOR
BRUCE BABBITT, Secretary
U.S. GEOLOGICAL SURVEY
Robert M. Hirsch, Acting Director
For additional information Copies of the report can be
write to: purchased from:
District Chief U.S. Geological Survey
U.S. Geological Survey Earth Science Information Center
1016 Administration Building Open-File Reports Section
1745 West 1700 South Box 25286, MS 517
Salt Lake City, Utah 84104 Denver Federal Center
Denver, Colorado 80225
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CONTENTS
Page
Abstract 1
Introduction 1
Purpose and scope 3
Methods of investigation 3
Previous studies 4
Data-site numbering system 4
Acknowledgments 5
Physical setting of lease tract and vicinity 5
Location and topography 5
Climate 5
Geology 9
Stratigraphy 9
Structure 11
Landslide hazards 14
Land use 16
Surface-water hydrology 17
Streamflow characteristics 17
Runoff and evapotranspiration 23
Peak and average annual streamflow 23
Water quality 29
Chemical quality 29
Suspended sediment 34
Erosion and sediment yield 37
Ground-water hydrology 38
Occurrence of ground water 38
Aquifer characteristics 49
Recharge 54
Movement 55
Discharge 57
Water quality 59
Ground-water inflow to Zion Narrows 64
Quantity of inflow 64
Source of inflow 65
Surface-water/ground-water interaction 67
Potential effects of mining 68
Surface mining 69
Hydrology 69
Water quality 69
Underground mining 70
Land subsidence above coal mines 70
Potential effects of subsidence in the lease tract 70
Future studies needed 71
Summary and conclusions 72
References cited 74
Supplemental information 79
in
ILLUSTRATIONS
[Plates are in pocket]
Plate 1. Map showing geology, spring locations, and water-
quality diagrams for the L.C. Holding coal-lease
tract area, Utah.
2. Map showing areas of ground instability and location
of monitoring wells and streamflow-sampling sites
for the L.C. Holding coal-lease tract area, Utah.
Page
Figure 1. Map showing location of the L.C. Holding
coal-lease tract 2
2. Diagram showing data-site numbering system used
in Utah 6
3. Photograph showing vegetation and slopes typical
of the L.C. Holding coal-lease tract 7
4. Graphs showing mean monthly precipitation and
temperature at Alton and Zion, 1951-86 8
5. Satellite imagery showing structural features
near the L.C. Holding coal-lease tract 12
6. Photographs showing joint systems in the Navajo Sandstone
in Zion National Park 13
7. Photograph showing slump in coal-bearing member of the
Tropic Shale near site SW16 14
8. Photograph showing displacement of pavement by Coal
Hill landslide 15
9. Map showing location of and selected water-quality
diagrams for springs, streamflow sites, and a stable
isotope sample site in Zion Canyon 24
10. Graphs showing mean monthly precipitation at Alton
and mean monthly streamflow at two gaging stations
on the North Fork Virgin River 26
11. Graph showing mean monthly precipitation at Alton and
mean monthly runoff at North Fork Virgin River
below Bulloch Canyon, SW2 1975-83 27
,
12. Graph showing relation of streamflow to suspended-
sediment concentration at site SW2, North Fork Virgin
River below Bulloch Canyon, October 1974 through
October 1976 35
13. Photographs showing sediment load in the North Fork
Virgin River before (A) and during (B) thunderstorm
runoff 36
14. Map showing location of and water-quality diagrams
for wells and springs outside the L.C. Holding
coal-lease tract 46
15. Map showing location and elevation of selected springs
in Zion Canyon 56
16. Graph showing specific conductance for samples from
springs discharging from the Navajo aquifer,
Zion Canyon 62
17. Graph showing cumulative departure from normal
precipitation at Zion and Alton, 1967-87 66
IV
TABLES
Page
Table 1. Streamflow, temperature, specific conductance, and
suspended-sediment concentration for selected
streamflow sites 18
2. Regression equations used to compute peak and average
annual streamflows from ungaged tributaries in the L.C.
Holding coal-lease tract area 28
3. Streamflow and chemical quality of water from selected
streamflow sites 30
4. Streamflow, suspended-sediment concentration, and
particle-size distribution for selected streamflow
sites 32
5. Rating factors for estimating source-area sediment
yield for the L.C. Holding coal-lease tract 39
6. Estimates of suspended-sediment load for gaging stations
along the North Pork Virgin River below Bulloch Canyon
(SW2) and above Zion Narrows (SW4) 41
7. Records of selected wells 42
8. Discharge and chemical quality of water from selected
springs and wells 50
9. Compilation of discharge data for springs in and
adjacent to the L.C. Holding coal-lease tract 58
10. Chemical analyses for dissolved metals and stable
isotopes in water from selected springs and wells 60
.
CONVERSION FACTORS, ABBREVIATED WATER-QUALITY UNITS,
AND VERTICAL DATUM
Multiply By To obtain
Length
foot (ft) 0.3048 meter
inch (in.) 2.54 centimeter
mile (mi) 1.609 kilometer
yard (yd) 0.9144 meter
Area
acre 0.4047 square hectometer
square foot (ft2 0.09290 square meter
)
square mile (mi2 2.59 square kilometer
)
Volume
acre-foot (acre-ft) 0.001233 cubic hectometer
Flow
cubic foot per second (ft3/s) 0.02882 cubic meter per seco
gallon per minute (gal/min) 0.06309 liter per second
Yield
acre-foot per square mile 0.0004761 cubic hectometer per
(acre-ft/mi2 square kilometer
)
Density
tons per acre-foot (tons/acre-ft) 0.00136 megagram per cubic
hectometer
Specific Capacity
gallon per minute per foot 0.20696 liter per second per
[(gal/min)/ft] meter
Hydraulic Conductivity
foot per day (ft/day) 0.0003528 centimeter per second
Transmissivity
foot squared per day1 (ft2/day) 0.09290 meter squared per day
1 An alternative way of expressing transmissivity is cubic foot per day
per square foot per foot of aquifer thickness [(ft3/cl/ft2)/ft]
vi
Gradient
foot per mile (ft/mi) 0.1894 meter per kilometer
Concentrations of chemical constituents are given in milligrams per liter
(mg/L) or micrograms per liter (ng/L). Milligrams per liter is a unit
expressing the concentration of chemical constituent as the weight (milligrams)
of solute per unit volume (liter of water). One thousand micrograms per liter
is equivalent to 1 milligram per liter. The concentration of chemical
constituents, in parts per million, is about the same as the concentration in
milligrams per liter for concentrations less than 7,000 mg/L.
Specific conductance is given in microsiemens per centimeter at 25 °C
(jxS/cm).
Water and air temperature are given in degrees Celsius (°C), which can be
converted to degrees Fahrenheit (°F) by the following equation:
°F = 1.8(°C) + 32.
Sea level: In this report "sea level" refers to the National Geodetic
—
Vertical Datum of 1929 a geodetic datum derived from a general adjustment of
the first-order level nets of the United States and Canada, formerly called Sea
Level Datum of 1929.
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