WELLOG
COCHISE COUNTY WATER
WELLOG has been active in the local and county politics of WATER.
The two primary issues concerning water anywhere
in the world are Quantity and Quality.
QUANTITY:
The fact is that 75 percent of our world is
covered with water. An additional fact is that less than 1 percent of the water
is drinkable.
QUALITY:
One of the properties of water is its ability to
transport other materials both chemical and organic. Water quality can be
affected by many different types of contamination. Contamination enters into a
water system from sources that are natural and manmade. Because many natural
elements found in the earth and in the atmosphere are soluble in water, water
can absorb and combine with them. Water vapor carries airborne chemical
elements in the atmosphere which form precipitation that arrives at the surface.
When water arrives at the surface of the earth, it combines with ingredients
found in the soil. Soil may contain natural elements including organic
compounds and bacteria. Other elements are manmade chemicals that form
compounds with water and are transported as the water moves downstream and into
the earth. Many of these natural and manmade compounds and bacteria are harmful
and affect water quality.
Is there water in the desert?
Yes, even in arid desert areas water can be
found.
Where is the water?
Water is either found on the surface (surface
water) or in the ground (ground water).
Where does our water come from?
Our water comes from the oceans and continental
areas of the earth where water evaporates into the atmosphere. Water vapor is carried
by wind currents and when conditions are right, the atmosphere releases the
water in the form of precipitation. Precipitation reaches the surface of the
earth in the form of rain, snow, hail and condensation
(fog).
Where does water in the form of precipitation go?
Precipitation that reaches the surface is
subjected to several processes.
The first process is the process of evaporation.
A small percentage of rainfall and snow melt is evaporated by dry air and
re-enters the atmosphere. That water vapor is transported by moving air
currents to other places in the world.
The second process is called evapotranspiration.
Water that is not evaporated immediately, is absorbed into the surface of the
earth. The surface of the earth is saturated with plant life. Plants use water
in order to create a process called photosynthesis. Plants grow larger and as
they grow, they consume more water. Roots of plants may extend hundreds of feet
into the ground in order to absorb as much water as possible. Plants use about
80 percent of the water that appears on the surface of the earth. The amount
varies according to the region and the amount of plant life and types of plant
life.
The remaining water enters into the water table
and is eventually used for human or other animal and plant uses after being
returned to the surface.
All three processes form part of a cycle which
is completed when water evaporates into water vapor and is returned to the
atmosphere.
The hydrologic cycle is the complete process
that water undergoes from atmospheric precipitation and return back into the
atmosphere.
AQUIFERS:
Water contained below the surface of the earth
is contained in formations called aquifers. Aquifers consist of sedimentary
rocks like sandstone, fractured metamorphic rock, sometimes fractured igneous
rocks, and porous limestone formations. In some areas, more than one aquifer
may exist in different layers of the earth at different depths. Multiple
aquifers are usually separated from each other by layers of earth that
are not able to allow water to flow called aquitards. An aquitard will usually
isolate one aquifer from another. Water quality can vary from one aquifer to
another because of its isolation from other aquifers. Aquifers located near the
surface may be contaminated from surface runoff. Deeper aquifers are generally
less contaminated and contain higher quality water.
Aquifers are contained within areas having a
regional boundary. Boundaries define a line surrounding a region where water
does not flow into or out of that region. This type of region is referred to as
a basin. Precipitation that occurs in mountains will move down streams, creeks,
rivers, washes, and through channels to a basin where it is contained.
BASINS:
Basins are large regions that contain aquifers
in which water does not move out of or into that region.
Active
Management Areas give jurisdiction of water regulations and water rights to the
State.
BOUNDARY:
The Willcox basin is bounded on the north by the
surface drainage divide with the Aravaipa Creek basin and the Pinaleno
Mountains; on the east by the Dos Cabesas and Chiricahua Mountains; on the
south by the Pedregosa and Swisshelm Mountains, square top hills, and a series
of smaller hills and ridges between the communities of Pearce and Sunizona; and
on the west by the Dragoon, Little Dragoon, Winchester, and Galiuro Mountains.
DEPOSITION:
The Willcox basin is a debris-filled valley that
has been without external drainage for most of its geologic history. Whitewater
Draw in the extreme southern end of the basin drains into the
adjacent Douglas basin. And all of the remaining surface drainage is
internal and flows to a large, roughly triangular-shaped alkali flat known as
the Willcox Playa. The playa, a nearly level plain, almost devoid of
vegetation, occupies approximately 50 square miles in the central part of the
basin. The Willcox playa is a remnant of the
Pleistocene-age lake Cochise.
ELEVATIONS:
Land surface altitudes in the Willcox basin
range from 4134 feet on the Willcox playa to 10,720 feet
atop Mount Graham in the Pinaleno Mountains on
the northern basin boundary.
RAINFALL:
Average annual rainfall ranges from 11 inches
per year at Cochise to 18 inches per year at the Chiricahua National
Monument. Average annual snowfall ranges from 1 to 4 inches in the valley floor
to over 13 inches in the surrounding Chiricahua Mountains.
OCCURANCE:
Groundwater in the Willcox basin occurs
predominately in a regional aquifer system in which the unconsolidated alluvium
is the main water-bearing unit. Although the bulk of this unit consists of
impermeable silt and clay, the relatively thin and interconnected sand and
gravel layers are highly permeable and, in some areas, are capable of yielding
large quantities of water to irrigation and domestic wells. Groundwater also
occurs in the older consolidated alluvium that underlies the unconsolidated
alluvium. The poorly to moderately cemented deposits of the consolidated
alluvium exhibit very low to moderate permeability, but large quantities of
water may be obtained if sufficient thickness of saturated material is
penetrated by a well.
RECHARGE:
The principal source of recharge of the Willcox
basin is from infiltration of runoff along the mountain fronts. Little or no
recharge is believed to result from direct precipitation, due to high
evapotranspiration rates. Seepage of applied irrigation water may contribute a
significant amount of water as recharge to the regional aquifer in the heavily
pumped agricultural areas.
(Brown and Schumann, 1969 p. 19)
Prior to groundwater development in the Willcox
basin the aquifer was in equilibrium with inflow (recharge from infiltration of
runoff and direct precipitation) equaling outflow (evapotranspiration) at about
45,000 acre-feet per year.
(Fleethey and
Anderson, 1986, sheet 3)
DISCHARGE:
Groundwater is discharged from the Willcox basin
by both artificial and natural means. The withdrawal of groundwater by pumping
is the primary source of discharge in the Willcox basin. A small amount of
groundwater also discharges from the basin as underflow to adjacent basins
through the alluvial fill. One avenue of outflow is southward to
the Douglas basin from the area southwest of Sunizona, and the other
area is northward to the Arivaipa basin.
WATER-LEVEL CHANGES:
Groundwater has been used in the Willcox basin
since the early 1900’s, but it was not until the late 1940’s and early 1950’s
that large-scale withdrawals for agriculture began. As the amount of cultivated
land and the number of wells in the basin increased, annual groundwater
withdrawals increased, reaching a peak of about 339,000 acre-feet in 1974.
(Wilson, 1991, sheet 1)
The U. S. Geological survey estimates
that the total amount of groundwater pumped in the Willcox basin since
groundwater development began is in excess of 7.2 million acre feet (Table 1,
Sheet 2). Water levels in at least 9 wells declined more than 200 feet between
1954 and 1970 (Mann and others, 1975 sheet 1).
Due to economic conditions many marginally
successful farms went out of production in the late 1970’s. Since that time
annual groundwater pumpage has steadily decreased. As a result of the decrease
in pumpage, water levels in the formerly heavily pumped areas have risen.
Wells in the Kansas Settlement area have shown the greatest rises in
water levels since 1975 (Hydrographs K, M, O, P, Q, sheet 2). Wells in the
north-central part of the basin in townships 11, 12 and 13 south, Ranges 23 and
24 east have shown smaller rises in water levels (Hydrographs A, C, E, F, sheet
2).
Wells completed in the shallow groundwater zone
near the Playa, have remained relatively unchanged since 1975 (Hydrographs H,
I, N, sheet 2). Water levels in some wells outside of the major pumping
areas declined during the period 1975-1990 (map, sheet 2). Water level changes
during the period 1975 – 1990 ranged from a decline of 67 feet to a rise of 61
feet observed in two wells near Kansas Settlement.
Source: State of Arizona Department of Water
Resources, Maps showing Groundwater conditions in the Willcox Basin, Graham and
Cochise
Counties, Arizona, 1990, By Paul Oram III,
Hydrologic Map Series Report Number 25; citations from (Brown and Schumann,
1969 p. 11-18).
DOUGLAS BASIN: NEW!
The Douglas basin occupies the southern part of
a large northwest-trending intermountain structural trough known as
the Sulphur Springs Valley. The basin is about 40 miles long and
varies from 10 to 40 miles wide. It includes approximately 950 square miles
extending from Mexico, north to Pearce. A resolution to impose an AMA on the
Douglas Basin passed. It has permanently curtailed future development of
Agriculture and Ranching in the Basin.
Frequently asked questions: FAQs for Douglas AMA | Arizona Department of Water Resources (azwater.gov)
Responsible regulation is needed. Permanently
curtailing the Future of Agriculture and Ranching in the Basin represents a
prime example of government over-reach. WELLOG has done our “homework” on this
government trespass based on the facts of the matter.
The desert southwest is in a drought. A drought
has a wide range of effects on water resources. WELLOG has published articles
on the subject of “Water in the Bank” for example that discusses the nature of
water stored in aquifers in the ground and the effect of deposits and
withdrawals. Simple mathematics can be used to provide an accounting method.
It’s as simple as addition and subtraction. Decision making should never be
done in response to special interest groups with irrational motives!
Link to “Water in the bank”
Link to an MS Excel spreadsheet that lists all
of the wells.
Link to the mathematics related to rational management.
MORE DATA IS NEEDED:
WELLOG is working to increase the database of current water levels
in Cochise County. Monitor
wells are located around Cochise County. Water levels are recorded and
displayed on Hydrographs. The data is updated on a regular basis.
If you have questions about water in Cochise
county contact info@wellog.com
REVISED 11-26-2023 © WELLOG 2007 – 2023
All Rights Reserved