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Spring Resource Issues

Tributary streams occupy 0.003 percent 

of the area of Grand Canyon; however, 

36 percent of the total riparian flora 

exists within those confines (John Rihs, 

hydrologist, GCNP, written commun., 

2002). Baseline, seasonal, and annual 

water-quality data from springs along 

the south rim and identification of spring 

sources are needed to address four issues 

identified by GCNP:

—The quality of water from springs 

and seeps can limit recreational use of 

the water.

U.S. Department of the Interior

U.S. Geological Survey

Assessment of Spring Chemistry Along the South Rim of 

Grand Canyon in Grand Canyon National Park, Arizona

—A U.S. Geological Survey and National Park Service Partnership —

USGS Fact Sheet 096-02

U.S. Geological Survey

Prepared in cooperation with the

NATIONAL PARK SERVICE

—Changes in the quality, quantity, 

and sustainability of flow from springs 

can affect the long-term health of 

biological communities and riparian 

habitats associated with these areas.

—Climate variability can affect 

spring flow and thus the riparian habitats 

associated with these areas.

—Ground-water pumpage from the 

Redwall and Muav Limestones south of 

Grand Canyon may affect spring flow.

Figure 1. Location of the study area.

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Spring flow from the south rim of 

Grand Canyon (fig. 1) is an important 

resource in Grand Canyon National Park 

(GCNP). Springs offer refuge to endemic 

and exotic terrestrial wildlife species and 

help maintain the riparian areas associated 

with this resource. Recent real estate 

development on the Coconino Plateau 

(fig. 1), a subregion of the Colorado Plateau 

south of Grand Canyon, has heightened 

the awareness of environmental groups, 

commercial developers, and resource 

managers to the importance of spring 

resources. Native Americans in the Grand 

Canyon region, such as the Havasupai 

Tribe, are concerned that ground-water 

pumpage may affect the spring resources. 

For Native Americans, springs are not 

only economically important but also 

culturally significant.

The U.S. Geological Survey (USGS) 

and GCNP began a cooperative program 

in 1999 under the auspices of the WaterQuality Monitoring and Assessment 

Partnership, a Clean Water Action Plan 

program (2002), shared between the 

USGS and the National Park Service 

(NPS). Nineteen springs have been 

sampled to date that issue from the 

Redwall and Muav Limestones along the 

south rim of Grand Canyon.
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The hydrogeology of the deeply buried 

Redwall and Muav Limestones and 

the hydraulic connection of these units 

with the overlying Pennsylvanian and 

Permian rocks of the Coconino Plateau 

near Grand Canyon are poorly known.

The water-bearing units are recharged 

primarily by precipitation that infiltrates 

outcrops of volcanic rocks, the Kaibab 

Formation, and the Coconino Sandstone 

in the higher altitudes of the Coconino 

Plateau (Johnson and Sanderson, 1968). 

Faults and fractures, many widened 

by solution, create zones of secondary 

permeability that could be the primary 

controls of ground-water movement. 

Ground water in the south rim area 

and in the northern parts of the plateau 

generally flows toward the south rim and 

discharges at springs and seeps in Grand 

Canyon (fig. 2). Springs and seeps 

typically occur at geologic contacts 

where water-bearing rocks are underlain 

by less permeable rocks. Large springs in 

the canyon are associated with regional 

faults. Very little is known about the 

movement of ground water through the 

rocks of the plateau; therefore, travel 

times to discharge points are unknown.

Population growth on the Coconino 

Plateau has raised concern about the 

potential demise of spring resources of 

Grand Canyon. Ground-water development near the communities of Valle and 

Tusayan, Arizona (fig. 1), has prompted 

GCNP to monitor flow from selected 

springs along the south rim of Grand 

Canyon. Variability in spring flow can 

indicate stresses caused by ground-water 

development in the basins, or indicate 

changes in the regional climate.

Objectives of the Study

The objectives of the study are to:

—Accurately locate and map significant 

springs issuing from the Redwall and the 

Muav Limestones.

—Describe the general water chemistry 

of springs.

—Verify the source of water discharging at springs and determine the 

approximate age of spring water.

—Measure spring-flow discharge.

In addition to data collection at 

springs, water samples are proposed to 

be collected from wells in Tusayan and 

Valle south of Grand Canyon. Wells 

in these communities tap the Redwall 

Limestone or Muav Limestone for water 

supply and are believed to lie in the 

path of ground-water flow to south rim 

springs. Analyses of water samples from 

these wells are critical for determining 

the sources and flow paths of water that 

discharges at springs along the south rim 

of Grand Canyon.

Physical Setting

The study area extends across the 

Coconino Plateau, an area of about 

5,000 mi2 in the southern part of the 

Colorado Plateau in northern Arizona 

(fig. 1), to allow collection of information 

on spring source areas and ground-water 

development. The Coconino Plateau 

extends from GCNP south to the 

Mogollon Rim, and from near Winslow 

northwest to the Hualapai Indian 

Reservation. Altitudes within the study 

area range from 12,500 ft at San Francisco 

Mountain to 2,400 ft on the Colorado 

River near Grand Canyon. The greatest 

rainfall occurs during the southwestern 

monsoon from mid-June to early October. 

Snowfall on the Coconino Plateau can 

be significant at higher elevations and 

accounts for the greatest portion of the 

total precipitation in these areas. The 

climate of the Coconino Plateau changes 

with altitude. Above 7,000 ft, annual 

precipitation varies from 19.1 in. on 

the Kaibab uplift (fig. 1) to about 21 in. 

near Flagstaff (Sellers and others, 1986).

Figure 2. Schematic diagram of the geology of the study area showing a generalized 

south-to-north cross section from the south rim of Grand Canyon near Tusayan to the 

Colorado River. Springs receive recharge from precipitation that infiltrates rocks along 

the south rim and from ground water that flows to the springs from areas south of the 

south rim.

Along the Colorado River, the climate is 

continental and arid. Precipitation ranges 

from 5.9 in. at Lees Ferry (river mile 0) to 

9.1 in. at Phantom Ranch (river mile 86; 

Sellers and others, 1986).

Water-Bearing Units

The water-bearing units from which 

springs along the south rim typically 

issue are limestones and sandstones 

of Paleozoic age (fig. 2). Water in the 

Redwall and Muav Limestones is the 

primary source of spring flow along 

the south rim of Grand Canyon owing 

to faults and fractures (Metzger, 1961; 

Huntoon, 1974). Below the Muav 

Limestone, the less permeable Bright 

Angel Shale acts as a physical barrier to 

downward movement of ground water 

from overlying rocks (Huntoon, 1974).

Seeps and springs also occur from 

the Cambrian Tapeats Sandstone, which 

underlies the Bright Angel Shale, and in the 

Pennsylvanian and Permian Supai Group 

and the Permian Coconino Sandstone 

that overlie the Redwall Limestone.
Monument Spring at source, first major 

canyon to the east of Hermit Creek

Lonetree

Spring

Cottonwood Spring

Miners Spring Red

Canyon

Spring

Grapevine East Spring

Grapevine Main Spring

Hawaii

Spring

Hermit Source

Spring

Sam Magee

Spring

Burro Spring

Pipe Spring Pumphouse Spring

Monument Spring

Salt Creek

Spring

Boucher

East Spring

Horn

Creek

ne

ee

r Ga

Hermit

Cr k

ee Cr Cott wood on k

ee Cr k

ee

C

P r ipe

k

d

JT Spring

112°15 10' 5' 112° 111°55' '

Base from U.S. Geological Survey

digital elevation model data, 1:24,000

Universal Transverse Mercator Projection,

Zone 12

36°5'

36°

Hermit Creek

above Tonto Trail

near Grand

Canyon (09403043 )

Pumphouse Wash

Spring near

Grand Canyon

(09403013 )

EXPLANATION

Sampled spring—tail

points in direction

of spring flow

Streamflow-gaging

station with station

number

0

0 3 KILOMETERS

3 MILES

Cottonwood Spring above

confluence with

Cottonwood Creek near Grand Canyon (09402450)

iver R

Colorado

Phantom Ranch

Sampling Approach and

Chemical Analyses

Data have been collected from 

19 springs since the program began in 

1999 (table 1). Analyses of the stable 

isotopes of carbon (13C and 12C) are 

used to determine recharge areas. These 

isotopes are affected by photosynthesis 

and other biological and environmental 

factors (Drever, 1988). The 13C/12C 

value in water is dependent on the 

isotopic composition of carbon dioxide 

in the soil (rock) at the recharge area 

and on reactions between the water 

and carbonate minerals along the flow 

path (Lopes and Hoffmann, 1997). 

Strontium isotope data ( 87Sr and 86Sr) 

also help to identify flow paths. For 

example, water that receives recharge 

primarily through limestone has a 

heavier strontium composition (larger 

87Sr/86Sr value) than water that receives 

recharge primarily through volcanic 

rocks. Data from the analyses of oxygen 

(18O and 16O) and hydrogen (2H and 

1H) isotopes provide information about 

sources of recharge from rainfall or 

snowmelt and whether the recharge 

source has been affected by evaporation. 

Analyses of the radiogenic isotopes of 

carbon (1 4C) and hydrogen (3H, tritium) 

are used to determine ground-water 

age, which can be used to infer travel 

times along ground-water flow paths. 

Figure 3. Sampled springs and streamflow-gaging stations on the south rim of Grand Canyon.

Carbon-14 has a half-life of 

5,730 years, and tritium has a half-life 

of 12.3 years. Large amounts of both 

were released into the atmosphere 

during testing of nuclear weapons 

during the 1950s and 1960s (Fritz and 

Fontes, 1980). Baseline water chemistry 

determined from analyses of major ions 

and other constituents can allow future 

studies to measure changes in chemistry 

over time and potentially identify 

factors responsible for the changes. 

Concentrations of trace and rare earth 

elements also can potentially provide 

information useful for identifying 

recharge areas. Nutrient analysis 

provides information on the general 

water quality of the spring water.

Field measurements Analytes

pH and temperature

Specific conductance

Dissolved oxygen

Alkalinity

Spring discharge

Elevation and location of spring outlet

Major ions

Trace metals

Rare earth elements

Nutrients

Stable isotopes

(oxygen, hydrogen, carbon, and strontium)

Radiogenic isotopes

(tritium and carbon-14)

Radionuclides—gross alpha/beta

Table 1. Springs sampled, field measurements, and analytes

Springs sampled: Blue Spring, Red Canyon Spring, JT Spring, Miners Spring, Cottonwood Spring, 

Grapevine East Spring, Grapevine Main Spring, Lonetree Spring, Sam Magee Spring, Burro Spring, 

Pipe Spring, Pumphouse Spring, Horn Creek, Salt Creek Spring, Monument Spring, Hawaii Spring, 

Hermit Spring, Boucher East Spring, Mohawk Spring
References

Clean Water Action Plan, 2000, accessed 

February 1, 2002, at URL

http://www.cleanwater.gov/news/

fact_sheet.html/

Drever, J.I., 1988, The geochemistry 

of natural waters: Englewood 

Cliffs, New Jersey, Prentice-Hall 

Publishers, 437 p.

Fritz, P., and Jean-Charles Fontes, 

1980, Handbook of environmental 

isotope geochemistry, v. 1–2: 

Amsterdam, Elsevier Scientific 

Publishing Company, 557 p.

Huntoon, P.W., 1974, The karstic 

groundwater basin of the Kaibab 

Plateau, Arizona: Washington, D.C., 

American Geophysical Union, Water 

Resources Research, v. 10, no. 3, 

p. 579–590.

Johnson, P.W., and Sanderson, R.B., 

1968, Spring flow into the Colorado 

River Lees Ferry to Lake Mead, 

Arizona, Water-Resources Report 

number 34, Arizona State Land 

Department, 26 p.

Lopes, T.J., and Hoffmann, J.P., 1997, 

Geochemical analyses of groundwater ages, recharge rates, and 

hydraulic conductivity of the N 

aquifer, Black Mesa Area, Arizona, 

U.S. Geological Survey WaterResources Investigations Report 

96 – 4190, 42 p.

Metzger, D.G., 1961, Geology in 

relation to availability of water 

along the south rim Grand Canyon 

National Park, Arizona: U.S.

Geological Survey Water-Supply 

Paper 1475— C, 138 p.

Sellers, W.D., Hill, R. H., and SandersonRae, M., 1986, Arizona Climate, 

The First Hundred Years. Tucson: 

University of Arizona Department of 

Atmospheric Sciences, 80 p.

Boucher Spring downstream from source, first major canyon to the west of Hermit Creek

Long-Term Needs of GCNP

GCNP has the responsibility of 

protecting the natural resources of Grand 

Canyon and depends on partnerships with 

government and private organizations to 

address resource issues. Long-term needs 

of GCNP require a knowledge base 

of the Redwall and Muav Limestones 

and other water-bearing units of the 

Colorado Plateau including the Coconino 

Sandstone and Supai Group, in order to 

properly manage and protect the seeps 

and springs of the park. To help achieve 

this need, GCNP has initiated several 

programs and is pursuing continued 

or expanded programs comprising 

monitoring and research components 

including the following:

A. Water-chemistry data collection, 

compilation, and evaluation. The collection and evaluation of water chemistry 

data will continue as part of the park’s 

effort to identify the source of water 

to each spring and the geologic and 

water-quality characteristics of each 

spring. Future data collection will 

involve inventorying new springs, 

repeat sampling at selected sites to 

help determine seasonal variability, and 

collection of data from ground-water 

wells on the Coconino Plateau. Selected 

chemical constituents will be added to 

the analyses to refine the age estimates 

for spring waters. For example, 36Cl 

and chlorofluorocarbons (CFCs) from 

selected sites could be analyzed to 

provide additional information in support 

of estimates based on 14C and 3H data. 

 For further information, contact:

 Robert J. Hart

 U.S. Geological Survey, WRD

 2255 North Gemini Drive

 Flagstaff, Arizona 86001

 E-mail: bhart@usgs.gov or visit home 

page http://az.water.usgs.gov

 GCNP website: www.nps.gov/grca/water

Springs that issue from other stratigraphic 

units in the park that overlie and underlie 

the Redwall and Muav Limestones will be 

sampled to determine the hydrogeologic 

relations among the units.

B. Expand spring discharge monitoring. Continuous stage will be recorded 

and discharge will be measured on 

Cottonwood Creek, Pumphouse Wash, 

and Hermit Creek (fig. 3). Periodic 

measurements will be made at selected 

springs that are believed to issue from 

the Redwall-Muav Limestone aquifer. 

Additional spring-flow gages may 

be installed to increase monitoring 

coverage and to further document 

long-term changes in spring flow.

C. Develop and support geologic 

and geophysical framework. Gravity 

and aeromagnetic data are being 

used in the ongoing geologic surface 

mapping and geophysical evaluation. 

This data will provide information on 

the geologic structure that controls 

regional ground-water flow on the 

Coconino Plateau and spring discharge 

along the south rim of Grand Canyon.

D. Develop and support of biologic 

inventory, habitat mapping, and habitat 

modeling. Grand Canyon springs and 

seeps often support rare, endangered, 

endemic, and other species of special 

concern. Preserving and managing these 

areas cannot be done without baseline 

biological and riparian information. 

The park and its cooperators 

continue to collect baseline data on 

ecosystem health that are necessary 

for an effective monitoring program. 

 — Robert J. Hart, John Rihs (NPS), 

Howard E. Taylor, and Stephen A. Monroe