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~ WlUHIOCUMENT IS THE PROPERTY
Article 6
Part 2
Foreword • • • • • • • • •
Notice of Adoption ••••
Definitions••••• < ••
REG. 6- 2- 1.1 General • • • • " • • • • • · • · " • .. " · · • 1
6- 2- 10 2 Description of Interstate Haters • .. Q .. • • • · 2
6- 2- 1.3 Minor Basins .. · • " " o. • • .. .. ~ • .. 0 .. • " • 2
REG. 6.. 2- 2. 1 Colorado Rive r. • • • • • • " • 0 • • 0 0 • • • 3
6- 2- 2.2 Gila River .. 0 • • • • 0 • • .. 0 • • ." • • ., • " 17
REG. 6- 2- 3.1 General • ~ · • • .. • • • • " • .. • • .. .. <; • • 26
6- 2- 3.2 Agricultural. • • • .. .. " • • .. • • • · .. .. 26
6- 2- 3.3 Domest ic ~! ater Sources. • • • II • • • .. .. • .. · 26
6- 2- 3.4 Industrial. • • • · " • • • • • • .. • .. • " .. • 2.]
6- 2- 3.5 Propagation of Aquat ic and In 1dlife
Resources · • • • • • • • " • " • • • • • " • 27
6- 2- 3.6 Recreat iona1. 0 • · • • • " " · • 0 • • • • • • 28
6- 2- 3.7 Future Uses of Surface Water. .. .. 0 • " • • .. • 28
6- 2- 3.8 Classification of v./ aters According to Use " • • 2.8
6- 2- 3.9 Enhancement of \, Iater Qua Ii ty. .. • • " • • .. • .. 29
REG. 6- 2- 4. I General 0 • • • .. " " • • " .. • .. • .. .. .. .. .. .. 30
6- 2- 4.. 2 Consideration of Present Conditions and
Contributing Factors. • .. .. .. " .. .. • · · • • 30
6- 2- 4.3 Problems Associated with Hethods of Reducing
Pollutants.. • .. • .. • · .. " < l .. .. • • • • • .. 34
6- 2- 4.4 Additional Measures to Enhance \ I/ ater Qual ity. • 34
6- 2- 4.5 Qual ity Requirements for Specified Uses • " " • 35
1. Tributaries to Colorado River Below Lees Ferry
2. Summary of Diversions from the Colorado River - 1964
3. Arizona Agricultural Statistics
4. Cities Along the Arizona Reach of the Colorado River
5. Industrial Statistics
6. Mineral Production Statistics
7. Recreational Features Along the Arizona Reach of the Colorado River
8. Graphs of Total Dissolved Solids in the Colorado River at Selected
9. Total Dissolved Solids Variation in Lake Powell
IO~ Graph of Yearly \ delghted Average TDS at Selected Points in the
Colorado River
11. Farming Practices - Water Conservation and Quality Enhancements
12. Water Delivery System Improvements
13. Arizona Watershed Program
14. Evaporation Control
15.- Phreatophyte Control
16~ Water Reclamation and Exchanges
17. Water Demineralization at Buckeye, Arizona
18. Activities of the Arizona Water and PolluttDn Control Association
19. The Role of Arizona 5011 Conservation Districts in Conservation
of Water Quality and Quantity
~ r
~ d
20. Guidelines for Formulating Water Quality Standards for the
Interstate Waters of the Colorado River System
21. Minute 218 - Recommendations on the Colorado River Salinity
Problem and Memorandum of Understanding
22 a Gila River System Streamflow Data
23. Major Coldwater and Warmwater Fishing Areas on Interstate Waters
in Arizona
The following definitions appear in Chapter 16 of Arizona Revised Statutes
36- 1851 and apply thoughout this document:
1. IIBoard ll means the state board of heal tho
2. IlCotnmissioner ll means the commissioner of publ ic health.
3. " Council ll means the water quality control council established by
this chapter.
4. IlDepartment" means the state department of health, which for the
purposes of this article includes the council.
5. lIDisposal systemll means a system for disposing of wastes, either
by surface or underground methods, and includes sewerage systems,
treatment works, disposal wells, and other systems.
6. IIblearing officer ll means any Individual appointed by the council or
board to perform the duties of a hearing officer at any hearing.
7. IIPermit ll means a certificate or letter issued by the department
stating the conditions and restrictions governing the discharge
of a pcllutant into any waters of the state.
8. IlPerson ' J means the state or any agency or institution thereof, any
municipal ity, pol itlcal subdivision, publ Ie or private corporation,
individual, partnership, association, or other entity, and includes
any officer or governing or managing body of any municipality,
pol itical subdivision, or public or private corporation.
ge " ollution~ means such contamination, or other alteration of the
physical, chemical, or biological properties of any waters of the
state, including change in temperature, taste, color, turbidity,
or odor of the waters, or such discharge of any I iquid, gaseous,
sol id, radioactive, or other substance into any waters of the state
as will or is likely to create a publ ic nuisance or render such
waters harmful, detrimental, or injurious to public health, safety,
or welfare, or to domestic, agricultural, commercial, industrial,
recreational, or other beneficial uses, or to livestock, wild animals,
birds, fish or other aquatic life.
10. " Sewerage systemll means plpel ines or conduits, pumping stations,
and force mains, and all other structures, devices, appurtenances,
and facil ities used for collecting or conducting wastes to an
ultimate point for treatment or disposal e
11. " Treatment works Jl means any plant or other works used for the purpose
of treating, stabi1 izing, or holding wastes.
l2~ IIWastesli means sewage, industrial wastes, and all other liquid
gaseous, solid, radioactive, or other substance which may
pollute or tend to pollute any waters of the state. The term
" wastes" does not include agricultural irrigation and drainage
waters for which water quality standards shall have been established
pursuant to this article.
13" IIWaters of the state" means all waters within the jurisdiction
of this state including all streams, perennial or intermittent,
lakes, ponds, impounding reservoirs, marshes, watercourses,
waterways, wells, springs, irrigation systems, drainage systems,
and a]} other bodies or accumulations of water, surface and underground,
natural or artificial, public or private, situated wholly
or partly within or bordering upon the state.
The following terms and symbols also appear in this document and are
defined as follows:
1" " Biocidell means a material applied to plants or soil as a growth
regulator or pest control agent. These include 2 but are not
limited to, insecticides and weedicides.
2.. IIBOOI 1 means the 5 day arithmetic average of the 200 C biochemical
oxygen demand in mg/ l as determined by the method described in
the current edition of Standard Methods of Examination of Water,
Sewage and IndustrJ. a i_ It/ § . stes.--------- · - .
3. " Eutrophicationl' means the enrichment of a body of water by the
addition of nutrients that stimulate aquatic growth which may
cause taste, odor and esthetic problems 9
4 q " mg/ l" means mi 11 igrams per 1iter of water q
5. l~ illequivalents per lite~ l means the concentration of an ion In
mg/ l divided by the equivalent weight.
6.. Ilppmll means parts per mi 11 ion parts of water by weight. This
term is being replaced by the more popular term mg/ liter although
the two terms are nearly equivalent.
7. " Fecal Coliform" means those bacteria of the coliform group com · '
monly found in the intestinal tract of warm blooded animals.
8. " Primary contact recreation watersll means waters in which body
contact with the water is made such as swimming and water skiing.
9. " Secondary contact recreation waterll means water in which only
minor body contact with the water is made such as fishing and
10. " Cold water fisheryll means waters having an environment suitable
for salmonids.
11 0 ' IWarm water fisherytl means waters having an environment suitable
for species of fish other than salmonids.
12. " Colorado River", ' IColorado River System", and IIColorado River
; these terms are used interchangeably throughout the
document. They are meant to include all waters within the
Colorado River Basin with the exception of the Gila River
Drainage. Comments specific to a given portion of the basin are
so identified by using the name of the tributary, reference to
the main stem or other appropriate designation.
13. IIGlla Rlver" , " GIla River Systeml' , and " Gila River Basin't; these
terms are used interchangeably throughout the document. They
are meant to include all waters within the Gila River Basin.
Comments specific to a given portion of the basin are so identified
by using the name of the tributary, reference to the main
stem or other appropriate designation.
Article 6
Part 2
These Water Quality Control Standards apply to all waters of the State. This
includes both interstate and intrastate waters. Interstate waters are identified
for the ' ttlhven" ience of the Federal Water Pollution Control Administration.
These standards shall become Federal standards as well as State standards for
interstate streams upon approval by the Secretary of the Interior.
, t
Dam Site
Dam Site
I mpe ria 1 Dam
Laguna Dam .. ~ 1:-'~'"
G\\~. Y ~ Painted
~ Rock Dam
N. Int. __ J
lOunda; y Yuma
~ orelos Dam
° lJth......
~ r7~
y .[ h, ... ., t:~ ...
t: I 0....,~ ...
Existing Dams ........ " \ Charleston Dam Site
Proposed Dams ......... ~. t!. 0j: l~ - !--
- 1-
A. Colorado River and its tributaries from the Utah- Arizona border to
the southerly internatIonal boundary with the Republ ic of Mexico.
B. Chinle Wash from its source to the Utah- Arizona border.
c. Paria River for its entire reach within the State.
D. Little Colorado River drainage from the New Mexico- Arizona border to
its confluence with the Colorado River.
E. Kanab Creek for its entire reach within the State.
F. Virgin River for its entire reach within the State.
G. East main drainage channel 1 Yuma ValleYt from its source to the
Arizona- Mexico border.
H. Gila River from the New Mexico- Arizona border to Ashurst- Hayden Dam.
I. San Francisco River for its entire reach within the State.
J. San Pedro River from the Mexico- Arizona border to its confluence with
the Gila River.
K. Santa Cruz River above its confluence with the Gila River.
New Mexi
cated be
major tr
total wa
1ion acr
stream c
maj or SL
are oper
maIn to
which i!
and regl
supply I
There are several minor basins within the State that are not within the
Colorado River Basin. These include the Villcox Playa and several minor drainages
along the Arizona- Mexico border. They fall within the definition of the
waters of the State and are controlled by this document.
REG. 6- 2- 1.3 MINOR BASINS Water
is 10ca:
for re- ·
ated at
\ 4ater
ary and
the upp
the Col
Cent ra 1
to Cent
used to
and no
but the
to diVE
Verde \
- 2-
: 0
6- 2- 2
6- 2- 2. 1
, to
A. The Main Stem of the Colorado River: The gross watershed of the
Colorado River encompasses portions of the states of Wyoming~ Colorado, Utah,
New Mexico, Arizona, Nevada, and California, as shown on Plate 1. The upper
portions of the watershed are drained by'the Green, Colorado, and San Juan
Rivers. These main tributaries in turn flow into Lake POJell, which is located
behind Glen Canyon Dam near the Utah- Arizona boundary. Flows of these
major tributaries into Lake Powell provide approximately 90 percent of the
total waters available to the lower main stem of the Colorado River. The
average annual undepleted flow of the Colorado River is approximately 15 milIi
on acre- feet.
Enroute to Lake Powell, river waters in the Upper Basin ( that portion up~
stream of Lee Ferry) are diverted, used, and returned to the system. The
major such diversions and returns are regulated by control structures which
are operated under the United States Department of the Interior, Bureau of
Reclamation. ~ any of the Bureau1s authorized projects in the Upper Basin remarn
to. be con, structed1._ and mal} Y exlsti..!: UL. Eioject~ 2.!:~. not yet fully developed.
Waters released from Glen Canyon Dam flow in the main stem to Lake Mead
which is located behind Hoover Dam. Lake Mead provides most of the storage
and regulation in the Lower Colorado River Basin. Hydroelectric power is
generated at both Glen Canyon and Hoover Dams. Lake Mead will serve as the
supply reservoir for the Southern Nevada Project. Return flow from the
Southern Nevada Project will reach Lake Mead through Las Vegas Wash.
Water released from Hoover Dam flows into Lake Mohave behind Davis Dam which
is located just north of the Nevada- California boundary. Lake Mohave is used
for re- regulation of releases from Hoover Dam. Hydroelectric power is generated
at Davis Dam.
Water released from Davis Dam crosses the Nevada- Arizona- California boundary
and flows through the broad Mohave Valley for 33' miles before reaching
the upper end of Lake Havasu. Lake Havasu, which is a widened portion of
the Colorado River behind Parker Dam, is about 45 miles in length. The
Metropolitan ~ Jater District of Southern California diverts water from Lake
Havasu for transport to the coastal regions of Southern California. The
Central Arizona Project plans to divert water from Lake Havasu for transport
to Central Arizona. Hydroelectric power is generated at Parker Dam.
Proceeding downstream, Headgate Rock Dam, located near Parker, Arizona, is
used to divert water for irrigating the lands of the Colorado River Indian
Reservation in Arizona. There is essentially no storage ; behind this dam,
and no hydroelectric power is generated. Some returns from drainage of the
reservation lands reach the Colorado River north of Palo Verde Diversion Dam,
but the principal drain empties into the river south of this dam.
Palo Verde Diversion Dam, which also has essentially no storage, is used
to divert water just north of Blythe, Cal ifornia, for irrigation in the Palo
Verde Valley of California. While there are some minor drainage returns to
- 3-
the Colorado River from Palo Verde Valley along the adjacent reach, the predominate
farm draInage returns from Palo Verde Valley are via Palo Verde
Lagoon- Outf~ ll Drain at the most southerly end of the Valley.
Cibola Valley, on the Arizona side, is located near the southern tip of
Palo Verde Valley. River water is pumped into Cibola Valley for irrigation~
Imperial Reservoir is located behind Imperial Dam, approximately 15 miles
north of Yuma, Arizona. Imperial Dam is the major diversion structure for
irrigation projects in the Imperial and Coachella Valleys and Yuma areas.
Releases made to the mainstream below Imperial Dam are essentially for the
purpose of satisfying treaty obligations with the Republic of Mexico. There
is only minor river water storage behind Imperial Dam. No hydroelectric
power Is generated.
Senator Wash Dam and Reservoir are located on the California side of the
Colorado River immediately upstream from Imperial Dam~ The reservoir provides
offstream regulatory storage and has a maximum available capacity of
12,250 acre- feet~ To provide regulation, water is either pumped fr6m the
Colorado River into the reservoir or released back to- the river. Water released
from the reservoir generates hydroelectric power. The Bureau of
Reclamation estimates that approximately 170,000 acre- feet of water can be
saved annually by short- term storage of releases from upstream dams in excess
of downstream requests for water deliveries o
Laguna Dam, which is located about six stream miles below Imperial Dam,
serves as somewhat of a foundation support for Imperial Dam~ There is a
storage capacity of 1,500 acre- feet behind Laguna Dam. Ability to utilize
this storage and to fluctuate the water level at Laguna Dam is essential to
movement of sediment downstream from the sluiceway channel at Imperial Dam and
for operational control of the river. The area between Imperial and laguna
Dams serves as a depository for silt removed; by the desilting works at Imperial
Dam. The importance of this desilting operation Is covered in Reg. 6- 2- 3.5~
The routing of water diverted from Imperial Darn and measured surface return
flows to the Colorado River between Imperial Dam and the Republic of
Mexico boundary is difficult to describe verbally, and is better explained
schematically in Plate 2.
Waters reaching Morelos Dam, just south of the Northerly International
Boundary with the Republic of Mexico, are diverted into the Mexicali Valley
for domestic, irrigation and other beneficial uses.
INTO THE OCEAN" The management afforded by the present system of storage
reservoirs permits delivery of the highest quality water now economically
possible considering that the supply is fully utilized. Water will be wasted
to the ocean only after all of the upstream reservoirs are filled to storage
capacity and all beneficial uses have been satisfied~ This condition is not
antictpated in the foreseeable future~
B. Tributaries to the Colorado River from Arizona: There are numerous
tributaries to the Colorado River from Arizona in the 700 river miles between
- 4-
> re-on~
~ Trlbutaries discussed in REG. 6- 2- 2. IB
'. e
, ere
In and
perl a 1
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~ ge
GROSS BASIN AR EA: 242,000 Sq. M L
AREA' 110,000 Sc; Mi.
ARE A: ' 32, 000 Sq. Mi.
-- -> Measured surface return flo'Ws
Northerl~ Interna!- i.. onal Bou_ nEa..=... ry,,--_
Alamo Canal
Gravi ty Main Canal
North Gila Valley . J I
South Gila Valley J I
J! al2.. te!!. B; L Retu. rns_ _ _ _ .. J
_ WF1! O~- M.. 9h~' W! s.. D£ a~ n 305,1< 2.. 0fl
Gila River
3.. 31.3~ AF .. 1 ~ t
°", 1
. U.::\ tI
r- l l _____ _ 1 _
Southerly International Boundary
79, 0
AF t
~ 1---------,
All American Canal
---::;>~ Diversi ons
Page ( Glen Canyon Dam) and Yuma. A brief description of the significant
str~ ams follows, and available specific data on quantity and quality of
wat'e'ricontributed appears in Exhibit 1 where applicable. The Total DissolVed
Solids ( TDS) change given for each tributary is for present conditions.
As the flow from the Upper Basin decreases, the effect is expected
to increase by up to one- third from each tributary.
1. Paria River - The Paria River joins the Colorado River just
downstream of the Lees Ferry USGS gaging station. The river flows through
remote country from southern Utah.. The water has a high mineral content, but
is relatively free of other contamination. The TDS load at the Colorado River
is increased less than 2 mg/ l by flow from this tributary. ( See Exhibit 1)
2. Little Colorado River - The Little Colorado River joins the
Colorado River about 55 miles below Lees Ferry. The river essentially starts
in eastern Arizona near Greer, although there are some minor intermittent
flows in creeks from New Mexico. The water has a medium to high salinity,
depending on the flow rate. A major problem is the contribution of salts
from Blue Springs, about 13 miles upstream from its mouth on the Navajo
Indian Reservation. These springs contribute about 547,400 tons of salt per
yeaf ' t6 the Colorado River. The TDS load of the Colorado River is increased
by about 28 mg/ l by this tributary, with about 20 mg/ l attributable to the
Blue Springs. This problem is being investigated at the present time by the
Arizona Interstate Stream Commission. ( See Exhibit 1)
3. Bright Angel Creek - The Bright Angel Creek enters the Colorado
River from the north in Grand Canyon National Park. The flow is mostly from
spr1ngs near the North Rim of the Grand Canyon, and the quality of the water
is good. The TDS load of the Colorado River is decreased about one ( 1) mg/ l
by the dilution effect of this tributary. ( See Exhibit I)
4. Tapeats Creek - Tapeats Creek is fed by springs on the north side
of the Colorado River in the northwest portion of Grand Canyon National Park,
a very remote and primitive area. The meager data indicate the discharg~ is
of low mineralization, and the dilution would reduce the TDS load of the main
stem flow of the Colorado Rtver by about 2 mg/ l. ( See Exhibit I)
5. Kanab Creek - Kanab Creek has a drainage area of about 1,600
square miles, of which about 1,000 square miles is tn southern Utah. The
river crosses the border between Kanab, Utah, and Fredonia, Arizona. The
water is fairly high in mineralization, but the total flow is relatively
small. The TDS load of the Colorado River is increased less than one ( 1)
mg!} by this tributary. ( See Exhibit 1)
6. Havasu Creek - Havasu Creek drains the Coconino Plateau south of
the Colorado River and enters the river about 13 miles downstream from Kanab
Creek. This is a remote area, and is inhabited by the Havasupai Indians.
The very meager water flow and quality data indicate good quality water of
low mineralization. The TDS load of the Colorado River is decreased by about
0.5 mgl1 by dilution from this tributary. ( See Exhibit 1)
7. Virgin River - The Virgin River begins in Utah, and flows into
Arizona near Littlefield, then into Nevada near Mesquite, and then into Lake
- 5-
Mead. The Virgin River contributes about 350,000 tons of salts per year to
the ColQ: rad~~ iver System, and the quality of the water is extremely poor. Ariz
The TOoS'load of the Colorado River is increased 14 mg! l as a result of this
tribut: ary. See Plate 1 and Exhibit 1 for location and details. It appears
that pn~ major source ( about one- fourth) of these salts is LaVerkin springs Ari2
( Dixie Hot Springs) in southern. Utah upstream from St. George. Other specif-ic
sources are not known at this time. D,
8. Si 11 Wi 11 iams River - The Bi 11 Hill iams River discharges into Lake sigl
Havasu just above Parker Dam. The river is erratic in flow since it drains a
desert area with sparse rainfall. Flash floods are commonplace, and these
are controlled by Parker Dam, and will be further controlled by the Alamo Dam Ari
now under construction about 35 miles upstream from the mouth of the river.
There is some irrigated acreage in this project. \: later Pollution Surveillance
System ( WPSS) data on water qual ity near the Alamo Dam site between October fIe
1963 and October 1961f ind icates that the TDS of the Bill ' tli 11 iams water is 001
within the range of 535 to 698 mg! l, or less than that of the Colorado River hi~
arriving at Parker Dam. thl
9. Gila River - The Gila Rlver joins the Colorado River just upstream
of Yuma, and below Laguna Dam. The Gila River is now almost complete-ly
controlled by upstream dams, and the water is completely util ized, often Ca
many times. Floodwaters have never exceeded the present capacity of the Ia
Gila River storage system upstream of its confluence with the Salt River, and N€
floodwaters have exceeded the capacity of the Salt- Verde System only twice in
the last 25 years. Painted Rock Dam, northwest of Gila Bend, is the final
flood control structure on the Gila River, and has only been used once, since tl
completion in 1959. During calendar year 1964, only 103 acre- feet of water wi
flowed past Dome, 12 miles upstream from the mouth of the Gila River near m
Yuma, and all of this flow originated downstream of Painted Rock Damo
10. Other tributaries - There are many small streams that flow for a d
sh~ rt period of time after rainstorms, but the flow is so intermittent that '"
very little data is available on total flow and water quality.
Many small springs and spring- fed tributaries, mostly in the reach
between Glen Canyon Dam and Lake Mead, contribute small quantities of water
and dissolved salts. Since most of these tributaries are in very remote
uninhabited areas, very little data on them is available. The data that
is available is shown in Exhibit l~
There are some intermittent creeks flowing from Arizona into Utah
above Glen Canyon Dam, and ultimately these may reach the San Juan or Colorado
Rivers. Most of these streams are in remote areas of the Navajo Indian Reservation.
C. Tributaries to the Colorado River from Utah: In addition to tributaries
to the Main Stem of the Colorado River upst'ream of the Utah- Arizona border,
there are several streams that cross the Utah- Arizona border and flow through
Arizona before reaching the Colorado River. The significant ones are as
fol lows:
1. Paria River - This river is covered in Reg. 6- 2- 2.1 B . under
Arizona tributaries.
- 6-
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: his
! ars
: 0 lake
I ins a
: se
10 Dam
' er.
} 1ance
, ber
, and
ee in
or a
~ eser-ltar>
' ough
2. Kanab Creek - This creek is covered in Reg. 6- 2- 2.1 B under
Arizona tribut~ ries.
3. Virgin River - This river is covered in Reg. 6- 2- 2.1 B under
Arizona tributaries.
D. Tributaries to the Colorado River from Nevada: There are a few tributaries
to the Colorado River along the common Nevada- Arizona border. The
significant ones are as follows:
1. Virgin River - This river is covered in Reg.: 6- 2- 2.1 B under
Arizona trib" utaries since it flows through the northwest fipof Ari, zona.
2. las Vegas Wash - las Vegas Wash drains the las Vegas Valley and
flows into Lake Mead just above Hoover Dam. Although the present flow is
not great ( about 15,000 to 20,000 acre- feet per year), the salt burden'is
high, and the flow is expected to increase severalfold upon completion of
the Southern Nevada Project~ The TDS load of the Colorado River is increased
about 4 mg/ l by this tributary at the present time.
E. Tributaries to the Colorado River from Cal ifornia: The area within
California which drains naturally to the Colorado River is a narrow strip of
land varying in width from about 10 to 40 miles. This strip extends from the
Nevada- California border to the Cal ifornia- Mexico boundary.
The area is essentially semidesert, and stream flOWS are intermittent. Although
rainfall is sparse in this area~ the intensity of rainfall may be great
when it occurs, and flash floods have occurred. Flow and quality data is almost
non- existent.
F. History of the Colorado River Basin Development: The history of the
development of the Colorado River Basin fs important to the consideration of
water qua i ity.
1. General History- Irrigation development of the Colorado River
Basin started with the beginning of settlement about 1860. The Upper Basin
( above Lee Ferry) irrigated , about 800,000 acres by 1905, and about 1,400,000
acres by 1920. Development slowed down after 1920 because of both physical
and economic 1imitations in the ~ availabil tty of water. In the Lower Basin
Irrigation began in the Palo Verde V" dley in 1879, and development of the
Yuma area and Imperial and Coachella Valleys followed. Irrigation on the
Colorado River Indi, an Reservation was attempted in 1870, but inadequate flood
control almost stopped this development until 1942.
Early development of river control centered around the agricultural
economy of the area. The river fiow was very erratic and undependable.
Tremendous floods occurred in the lower Basin around the Yuma area when both
the Colorado and Gila River Systems reached high flow stages. The Colorado
River cartled huge silt loads, and led to the statement that the Colorado
River was lItoo thick to drink and too thin to plowlJ • The salt burden was
low at high flow, but very high when the floyJ was low.
The construction of dams on the Colorado River and its tributaries,
especially the Gila, Salt, and Verde Rivers, brought the river under control,
reduced the silt load, evened out the salt burden, and made agricultural operations
in the Lower Basin stable.
This development of the Colorado River has had considerable political
problems, and further development, including quality control, will have some
more political and legal problems.
2. Water Compacts and Treaties - The development of the Colorado
River has necessitated a number of compacts and treaties to protect the rights
of individuals and states to the use of water. The following are certainly
important when considering water quality criteria that could affect water use
under existing rights.
a. Colorado River Compact - The water of the Colorado River was
divided between the Upper and Lower Basins by the Colorado River Compact of
1922, with the division point at Lee Ferry. The compact recognized the potential
obligation of the United States to the Republic of Mexico.
b. Mexican Treaty - The treaty with Mexico, signed in 1944, provides
for annual delivery by the United States to Mexico of 1,500,000 acrefeet
of Colorado River water, with certain exceptions due to river flow conditions.
c. Upper Colorado River Basin Compact - This compact of 1948
apportioned the waters of the Upper Basin states ( including 50,000 acrefeet
to Arizona annually) to allow for orderly and proper development of the
t: 1pper Basin.
d. Boulder Canyon Project Act - This Act of Congress apportioned
the waters of the Lower Basin among the Lower Basin states and was subsequently
interpreted by the United States Supreme Court in Arizona v. California, 373
e. Water Quality - None of the agreements or compacts have specifically
mentioned water quality. The treaty with Mexico provides that Mexico
will take from any and all sources •••• whatever their origin, the waters to
which she is entitled. Water quality is recognized as a factor to be considered
in recent legislation authorizing the construction of projects in the
G. Diversions of Water Along the Arizona Reach: Major United States projects
divert and use water from the Colorado River along the Arizona reach. A
description of these diversions, by states, follows, and data is summarized in
Exhibit 2.
1. Arizona Projects:
a~ City of Page - Page receives its municipal water supply from
Lake Powell. Sewage is treated in sewage lagoons with minor effluent return
to the Colorado River.
b. Colorado River Indian Reservation - This project has 99,375
- 8-
: rol,
' i ghts
in Arizona with assigned water rights as set forth in Arizona vs.
California Supreme Court Decree, and about one- third is presently being
irrigated by diversions at Headgate Rock Dam. About 60% of the water diverted
is returned to the river as measured surface return flows. In addition,
there are unmeasured surface and sub- surface returns to the river.
c. Yuma Project, Valley Division - About 52,000 acres in this
project are served by diversion at Imperial Dam via the All American Canal
to the Yuma ~ 1a i n Cana I by a siphon under the Co lorado RIver. A port ion of
the water diverted passes through measured surface drains and wasteways
back to the Colorado River south of the Northerly International Boundaryor
to Mexico over the Southerly International Boundary near San Luis,
Sonora. Additional drainage facilities are needed in portions of the
valley, particularly in the area adjacent to the mesa.
d. Gila Project - Water is diverted at Imperial Dam via the
Gfla Gravity Main Canal to service an authorized project area of 115,000
acres. This project consists of the following units:
:> n-
North Gila Valley Irrigation District
Yuma Mesa Irrigation and Drair, 3ge District
Yuma Irrigation District ( South Gila Valley)
Wellton- Mohawk Irrigation and Drainage District
: he
> ned
lent 1y
lec if i~
d in
Surface drainage from the Gila Projects is returned to the Colorado
River above the Northerly International Boundary except that the WelltonMohawk
drainage facilities include a bypass channel which extends past Morelos
Dam. This bypass channel was put into operation on November 16, 1965, and
the Mexican Government has the option of deciding whether the drainage waters
shall be discharged above or below Morelos Dam 4 About 30% of the water diverted
Is returned to the river as measured surface drainage or control water.
e. Yuma Auxiliary Project - Water is diverted at Imperial Dam via
the Gila Gravity Ma'in Canal to irrigate 3,406 acres in this project, which
includes certain Warren Act Lands. There is no measured return flow.
f. City of Yuma - The City of Yuma presently receives most of
its water through the Yuma Main Canal. The city's contract with the Secretary
of the Interior provides for del ivery of the water from the river.
Sewage from Yuma is now discharged untreated to the river north of the
Northerly International Boundary, but plans are progressing for a sewage
treatment plant.
go Cibola Valley - Water is pumped from the Colorado River for
irrigation of the Cibola Valley.
h. Central Arizona Project - When authorized and built, this
project will divert water from Lake Havasu to provide much needed supplemental
water for domestic, industrial and agricultural purposes in Central
Arizona. There will be no return flows from this project. The economic
impact and importance ' of this project is discussed in Reg. 6- 2- 2.1 H.
i. Fort Mohave Indian Reservation - This project has 14,916 acres
- 9-
in Arizona with assigned water rights as set forth in the Arizona vs.
Ca 1iforn ia Supreme Court Decree.
j. Miscellaneous Diversions - These include domestic, agricuh
tural and industrial waters, and consist of direct diversions or by ground~
water pumping In the vicinity of the Colorado River. Water is used by
cities, recreational centers, small farms, power plants, etc.
b. Palo Verde Irrigation District - About 900,000 acre- feet of
water is diverted annually at Palo Verde Diversion Dam near Blythe for agricultural
purposes. Approximately 60% is returned to the Colorado River
either as measured surface drainage or excess diverted water, mostly in a
main drain at the lower end of the project.
3. California Projects:
a. Metropolitan Water District of South~~ n California - The
Metropolitan Water District aqueduct provides capacity for the annual diversion
of 1,212,000 acre- feet of water for domestic, industrial and agricultural
use on the coastal plain of southern California. There is essentially
no return fl~ J.
" f" Or
i n~
de 1i \
of tl
is nl
per yc
and b
2. Nevada Projects: The Southern Nevada Project is authorized to
from lake Mead, 300,000 acre- feet of water for use in t~ e las Vegas
The water will be used for domestic, agricultural and inqustrial pur-
The Bureau of Reclamation anticipates a return flow of approximately
acre- feet of water to lake Mead annually.
c. Imperial Irrigation District and CoachellaVaJley County
Water District - Approximately 3,500,000 acre- feet of water is diverted
annually at Imperial Dam via the All American Canal for various uses within
the Districts. There is no return flow ( other than seepage from the All
American Canal and flow regulation water) to the Colorado River. Agricultural
drainage water, canal seepage, and any excess water diverted flows to the
Salton Sea in California.
d. " yuma Project, Reservation Division - About 96,000 acre- feet
of water is diverted annually at Imperial Dam via the All American Canal for
agricultural use in the Bard Valley. A portion Is returned as drainage and
flow regulation water to the Colorado River between Yuma and the Northerly
International Boundary.
H. Economy and Natural Resources of Arizona: The economy of the entire
State of Arizona is intimately associated with. the development of the
Colorado Rivero Arizona is semiarid in character with a low average annual
rainfall and limited natural water supplies o Since 1947, the population of
the State has more than doubled, with more than 70% of the population residing
in Maricopa and Pima Counties. These two counties, along with Pinal
County, comprise the core area of the Central Arizona Project. This area
is now supplied with water by surface water systems on the Salt, Verde and
Gila Rivers and by pumping from the groundwater basins. The agricultural,
domestic and industrial users of this area are consuming all of the surface
water available and are pumping approximately 3,000,000 acre- feet of water
- 10-
zed to
s Vegas
rial pur:>
ximate ly
11 d ia9r
or a9ri ..
\ fer
in a
: ed
' icultura
~ the
- feet
na 1 for
ge and
~ erly
~ nt i re
lOnua 1
· on of
la 1
ra I,
per year more ~ han the natural groundwater replenishment. This annual overdraft
is clearly eviddriced by the accelerated decline of groundwater levels
and by land subsiden~ e" in some areas.
The central Arizona area desperately needs the additional water to be
delivered & y the Central Arizona Project Aqueduct from Lake Havasu, but the
supply availa~~ e is still far short of the present overdraft, and the needs
of the area are still growing. The quality of the presently available water
is not always good with respect to its salt content. This quality is further
degraded by multiple reuse since almost all beneficial uses of water
add salts of some variety to the water.
The remaining areas of the State face similar problems of short supply
and/ or quality of water, and it is impossible to separate these factors
completely in any proposed program of supply or regulations on quality,
The total problem can only be solved by a major water augmentation program
for the Lower Colorado River Basin.
The peopl~ of Arizona have been striving to improve the quality of their
water- and ext~ ndthe supply for many years, long before a federal program
for ' pollution control was initiated. The quantity of water available has
been extended and the quality of the water has been enhanced by the foJJowing
practices end programs.
1. Farming practices have been steadily improved so that less water
is applied to the land per unit of crop yield. A report on this phase of
water conservation and quality enhancement is appended as Exhibit Jl.
2. Delivery systems for both surface and groundwater have been improved
through redesign t lining and conversion to pipelines to reduce seepage,
evaporation, salt pick- up, consumptive use by non- crop plants, and
delivery waste. Statistics on past and future programs are presented in
Exhibit 12.
3. Extensive watershed planning and controJ programs have been
initiated to increase the yield and improve the quality of water delivered
by the surface water systems. The Arizona Water Resources Committee, representingwHdlands,
banking, ranching, water authorities, timber, irrigation,
power, mfning, game and recreation and municipal ities, has an annual symposium
( 10th in 1966) to present and discuss experimental results and plan
larger scale experiments. A summary of watershed improvement accomplishments
and future programs is appended as Exhibit 13.
4. Means of evaporation control or reduction of evaporation on reservoirs
and streams have been investigated since evaporation of water from the
surface of reservoirs and streams not only reduces the supply but also increases
the salt content of the water remaining. A summary of activities
in this field is presented as Exhibit 14~
5. Extensive phreatophyte investigation and control programs have
been carried on to eliminate or reduce waste by certain types of vegetation
growing in or near streams. Evapotranspiration by these plants concentrates
salts in the soils and contributes to the salinity problems of
- 11-
the basin, so reduction of such growth would enhance water quality. A summary
of the phreatophyte control program is presented in Exhibit 15.
6. Programs to supply water of the best available quality for domestic
needs in exchange for treated sewage effluents for needs with lesser
quality requirements are being studied. Other water exchanges have been
implemented between areas of need and surplus, and more are needed. Examples
are presented in Exhibit 16.
7. Buckeye has been a pioneer in providing desalinized water for
domestic use. An expensive electrodialysis process was put in operation in
1962 to remove excessive salts from the only water available to the community,
making Buckeye the first town in the U. S. A. to have its entire water
supply treated by a demineralization plant. This was a local community
program, and no Federal or State funds were involved in this project. A
report on this project is presented in Exhibit 17.
It should be pointed out that all of the currently available methods
of desalinization separate the influent water into two streams, one relatively
pure, and one very salty. Disposal of the salty brine is a problem
for an area isolated from the oceans where most of the desaliniz~ tion programs
are promoted and tested.
8. The Arizona Water and Pollution Control Association meets annually
( the 40th annual meeting was held in 1967) to hear and discuss papers presented
by both local and out- of- state people involved in water supply and
disposal problems~ Educational programs are sponsored by the Association
along with other programs designed to upgrade the quality of Arizona water.
The Association is affiliated with the Water Pollution Control Federation
and the American "' Jater Works Association" A report of the Association is
included in Exhibit 18.
9. The Soil Conservation Districts of Arizona, both individually and
through their Association, have been actively engaged in projects aimed at
soil and water conservation and water quality improvement. A summary report
of the Association is presented as Exhibit 19.
10. River channelization projects in the lower Colorado River below
Hoover Dam have been in progress for several years by the Bureau of Reclamation
to reduce consumptive losses, erosion and quality degradation~ This
work is generally opposed by fish and wildlife interests alleging it destroys
natural habitat areas. Stabilized river flow and storage impoundments made
possible by dam construction have, however, enhanced some fish and wildlife
I. Natural Resource Values to be Protected: The following natural
resources of Arizona, although presently utilized effectively through good
management practices, shall be protected by Arizona1s water quality control
policy, and the tabulation is not intended to designate the order of importance:
1. Agriculture - Arizona1s principal crops ( alfalfa, citrus, cotton,
grains, and vegetables) are, grown on 1,160,000 acres scattered around the
- 12-
~ un i-lods
' 0-
lua II y
' e-d
: lW
: lmis
: Ide
i fe
, d
) r-
: on,
State, with some additional acreage for minor crops. Almost all of this
acreage is dependent on irrigation, and over 300,000 acres in addition to
that stated above are out of production due to water shortage. Growing conditions,
and particularly climatic conditions, are well adaptedto:, ct, op production
under irrigation on a year- round basis, and many high value- erops
such as cotton, winter vegetables and citrus fruits are produced in addition
to staple crops and feeds. The gross value of Arizona crops was
$ 344,400,000 in 1965. The continued production of these c: rops is dependent
upon our total water resources in Arizona, considering both quantity
and quality. The quantity of flow must not be unnecessarily reduced by
unrealistic quality considerations. Statistics on various phases of agriculture
are shown in Exhibit 3~
2. Urban Development - Urban development of Arizona has been growing
rapidly, and this growth has demanded increased recognition of the
need for a dependable supply of good quality water. Although the growth
has been highest in the Phoenix and Tucson areas, there has also been considerable
growth in cities adjacent to the Colorado River. An inventory
of cities along the Colorado River with pertinent water supply and disposal
data is shown in Exhibit 4. The growth of urban areas has accompanied
increased activity in tourism ( due to climate, recreational facilities
and natural attractions), manufacturing and service industries for
all State activities, including but not limited to agriculture, construction
and mining. Manufacturing statistics are shown in Exhibit 5.
3. Grazing and livestock Feeding - This industry is extensive in
Arizona, including the area along the Colorado River. The gross value of
livestock and products was $ 237,900,000 in 1965. Livestock production re~
quires water and also produces waste which must be controlled. Statistics
are included in the Agricultural Exhibit 3~
4. Mining Industry ~ There are only limited mining operations along
the Colorado River, but mining is a major factor in the economy of Arizona
and this industry requires huge quantities of water. Reuse of water in all
phases of mining has been practiced for many years, and pollution of streams
has not been a major problem. The minor problems are being corrected.
The gross value of mineral production was $ 580; 170,000 in 1965. The
principal metals were copper, gold, silver, lead and zinc, but substantial
quantities of sand, gravel, molybdenum, stone, uranium, 1ime, pumice and
other miscellaneous minerals were produced. Copper produced about 86% of
the total value. Statistics are shown in Exhibit 6 v
5. Fish and Wildl ife - Although much of Arizona is arid or semiarid,
the State is blessed with fish and wildlife resources v Protection of this
important natural resource is vital in the development of the Basin's water
resources. Over 3,400,000 man- days of fishing and hunting were enjoyed by
Arizona sportsmen during 1965. Additional man- days of hunting and fishing
were enjoyed on the Colorado River by license holders of adjacent states.
The Colorado River provides excellent feeding and resting areas for migratory
waterfowl, particularly in those portions of the river where oxbows
and sandbars exist. Additional value is created by shoreline vegetation
which provides habitat for numerous species of mammals and birds.
- 13-
Both the State and Federal Government have responsibilities under
existing law to preserve and develop the fish and wildlife resources of the
Colorado River, and cooperation among the states is vital and necessary.
The Federal Government by virtue of existing treaties with Great Britain
and Mexico, is responsible for management of the nation's migratory bird
resource. This responsibility is implemented along the Colorado River by
the Bureau of Sports Fisheries and Wildlife of the U. S. Fish and Wildlife
Service. Both National and State Wildlife Refuges have been established to
preserve waterfowl wintering habitats n
The natural habitat has been constantly changing since the area was
settled by man. A significant portion of the habitat no longer exists due
to river control and land development, and the wildl ife has decreased
accordingly in species and numbers. Channelization and controlled flows
have eliminated many of the productive backwaters$ bypasses, and oxbows
that served as spawning and nursery areas for warm water fishes, and have
reduced angling potential for these species.
In contrast, the vast reservoir storage system created by the construction
work of the Bureau of Reclamation has vil · tually el iminated flood
flows, reduced turbidity, and lowered summer water temperatures so that
extensive reaches of the Colorado River are now more suitable for trout.
Fish are supplied by a National Trout Hatchery at Willow Beach and by the
three State Game and Fish Departments involved in the Arizona reach of the
Colorado River.
6. Recreational Use - In addition to the natural recreational resources
in Arizona,. the control led river flows resulting from the operation
of dams and related water projects have created stable recreational resources
in the Colorado River. For the most part, this recieational potential still
remains to be developed. Stable water impoundments behind the dams attract
fishermen, boaters, water skiers, campers and persons interested in being
near the attractive water during the pleasant fall, winter, and spring seasons.
Recreation is a year- round activity, however.
Public recreation is permitted on substantial portions of the accessi"
ble land along the Colorado River from the Utah- Arizona border to the Mexican
border. There are numerous public forests, parks, marinas and other points
of interest not only to residents of the adjacent areas, but also to national
and international visitors o The major facilities are listed in Exhibit 7.
It is difficult to determine the overall recreational use of the
Colorado River because of the variety of deVelopments spread out over the
745 mile reach of the river in Arizona~ The recreationists who ceme on
peak weekends for special events in seme sections jam commercial and public
facilities and overflew onto every available piece of land along the river.
Somewhat uncontrolled use has occurred on other reaches of the river and
adjacent lands. Individuals and commercial interests have moved onto the
Federal lands, and have built structures varying from Shc1Cks to well- established
motels, trailer parks, fishing camps, and resort developments.
Recreational use of the river has created some serious pollution prob-
- 14-
i r
: he
= e
: e
i 11
lems because of the lack of adequate sanitation focil ities. Adequate facilities
will have to be provided, and the recreationists themselves are going
to nave to cooperate in making the river areas safe and esthetically enjoyable.
Recreational use of the Colorado River area will expand along with
the population growth in the contributing metropolitan areas and as the
physical features are developed. The major recreation objective will be
reached if the quantity and qual ity of water are maintained, and the
esthetic values of the area are preserved~
7. Forest Products Industry - The four mill ion acres of commercial
forest land, out of the total offfmillion forested acres in the State, are
largely situated in the northern, higher altitude areas. Managed for
multiple use the commercial forest area provides not only timber, but has
important values for water production, recreation, I ivestocki forage, and
t" iildlife. Arizona1s forest lands playa big role in provlding water to the
consumer. Much of the surface water consumed annually originates within
the State as runoff from the relatively high water- yielding forest o
The forest industry in Arizona annually harvests about 66 million
cubic feet of sawtimber and produces in excess of 300 million board feet
of lumber. The pulp and paper segment annually uses 100,000 cords of
pulpwood and chips from sawmill residual equivalent to an additional
150,000 cords. It produces about 150,000 tons of newsprint and kraft
linerboard annually. The paper industry requires a significant quantity
of good quality water.
J. Water Quality Considerations: THE Q. UALITY AND QUANTITY FACTORS OF
THESE PARAMETERS. Typical main stem flows, major diversions and return
flows, are shown along with pertinent sal inity data on Plate 3 for reference~
The Colorado Basin States Conferees, in drafting the Guidelines for Formu-
1ati"" "' later Qua 1i ty Standards for the Interstate Waters of the Colorado
River Syste~"", recognized that water quality standards could drastically
restrict present and future uses of the Colorado River water under existing
compacts. The following data on the qual ity of water in the Arizona reach
of the Colorado River is presented to provide the basis for stream standards
listed in Sec. 6- 2N 6 of this Water Qual tty Control Pol icy for the Colorado
River in Arizona:
1. Quality of Vater Reaching Arizona - Historically, the water
reaching Arizona in the Coiorado River at Lees Ferry has been high in both
salt and silt burden o Other pollutants have been negligible. The salinity
has been steadily increasing due to both increased use in the Upper Basin
and to depletions by trans- mountain diversion of the best quality water
near the headwaters of the Colorado River. The quality of the water at
Lees Ferry has been monitored diligently by the USGS, and excellent published
records for the 1941- 1964 period are available for comparison with
other stations on the Colorado River. The Total Dissolved Solids ( TDS) in
milligrams per 1iter ( mg/ l) is probably the best single parameter defining
the qual ity of the water.
)\- See Exhibit 20
- 15-
Examination of the record indicates a wide variation in dai ly, weekly,
monthly and yearly figures for TOS, and any water quality standards
proposed wi 11 have to recognize this feature. In general, the TDS is low
at high water flows and high at low water flows. This variation is discussed
under sources of salinity. Variations in TDS at Lees Ferry are
shown in Exhibit 8.
Further development of the Upper Basin and increased use of the water
upstream is expected to further degrade the water as far as TDS is concerned.
In addition, further control of the flow of the river upstream
wi 1\ cause variation of the quality of the water. As an example. the
effect of the closing of the gates at Glen Canyon Dam is seen in the TDS
record for Lees Ferry in Exhibit 8. A partial explanation is shown in TDS
variations in Lake Powell, Exhibit 9.
Future storage in upstream reservoirs will ultimately decrease the
flow in the Colorado River without appreciably changing the total salt
burden, so this will increase the TDS. The present predictions are that
the present TDS content will increase by 22 to 43% by 1990 ( 7) ( IS). Other
authorities prognosticate a somewhat lesser increase in TDS accompanied by
a deterioration in sodium and chloride content ( 16). These estimates are
not keyed to the year 1990 and hence a direct comparison is difficult.
2. Quality of Water Released from Lake Mead - The water record for
water released at Hoover Dam shows higher average TDS for water than that
at Lees Ferry, but with much less fluctuation in quality because of the
storage in Lake Mead. The TDS content appears to be gradually increasing.
The higher TDS can be attributed mainly to the increased TDS at Lees
Ferry and natural sources of salinity between Lees Ferry and Lake Mead
since there is negligible use of the Colorado River water in this reach.
Some of these natural sources of salinity were discussed in Reg. 6- 6- 2.1 B, C p
with further data in Exhibit I. Control of these natural sources of salinity
should be investigated as a means of enhancing water quality, not only
in this reach, but in the Upper Basin.
Evaporation from the surface in the main stream and reservoirs is
a contributing factor to the increased TDS. For example, the record shows
that 907,200 acre- feet evaporated from Lake Mead in Water Year 1963, leaving
behind approximately 800,000 tons of salt. Some of this salt is believed
to have been precipitated out ( 7), but much of it undoubtedly contributes
to downstream TDS. TDS comparisons at various points in the river
are shown in Exhibit 10.
Future river salinity like future streamflow can be predicted only
from statistical records of past salinity and from knowledge of the changes
in the river caused by impo~ ndment and diminution of flow due to consumptive
use. The most recent predictions on future salinity vary somewhat,
but all indicate that progressive deterioration wi 11 occur. The Department
of Interior study ( 7) and the Hill study ( IS) represent the most probable
conditions. Hi 11 predicts that the TDS load by the year 1990 wi II increase
to 735 mg/ I at Lees Ferry and to 926 mg/ I at Lake Havasu, compared to the
- 16-
___ U,: ta_ h _
Paria River, 15,090 AF
TDS 117.3 Av
Bright Angel Creek, 20,460 AF, TDS 19
Change, Storage Zero
Little Colo. River 1 7 800 AF
Main Stem 15 250 000 AF
Grand Canyon, TDS 531 Av.
Stem 8 304 000 AF TDS 72
Bill Williams River, 18,380 AF
Gila River
Future Central Arizona Project
So. Nevada
-< Metropolitan Water Dist., 1,039,377
. c Calif. Projects, 3,651,610 AF
( Imperial, Coachella, Reservation)
"" Colo. R. Indian Res., 455,400 AF>
.<.. rr-:. P.;;;;; a=.. lo;;;.....: V:....;; e:.:. r..:;: d:.:;:. e...; I::..; r:;.: r-:.-=. D.::::. is:::., t:::..:.':... zz~ 9:%. 48.:::.. zz..: 1::.:: 0;.::: 0.....:.:; AF::...-_ Lf- l )- ChR..:. I~ R:.. 1..? 77JQQ AF _
J a1 CLV~ rde ~ r: t:. Di st~ .. 27. § ., 600 .., AF__
, c~
~ s
~ r
< Mexico Projects
Schematic diagram of the Colorado River main stem flow with major tributaries,
diversions and return flows. The inflow- outflow figures do not balance because
of sizeable unmeasured surface and sub- surface return flows to the river.
Department of Interior figures of 663 rng/ l and 865 mg/ 1 at these same stations.
These figures represent increases of 22. to 43% by 1990, and assume
that current practices are not changed, a water augmentation program will
not be implemented, future Upper Basin d~ velopments and trans- mountain
diversions will be made, and that natural sources of salinity will not be
3~ Quality of Water at Parker Dam - There is little TDS change in
the quality of water between Hoover and Parker Dams. Increased population
in this area, and increased recreational use could degrade the present quality,
especially bacteriologically. Increased control of sanitary waste
disposal from boats and recreational areas will be necessaryc
- 17-
There is apparently little bacteriological deterioration in this section
of the river, but new habitation along the river could become a source
of pollution.
The City of Yuma is presently discharging untreated sewage to the
river above Morelos Dam, and measures are being taken by the State Department
of Health and the City of Yuma to eliminate this pollution at the
earliest possible date.
5. Quality of Hater at Morelos Dam - The flow of the Colorado River
has been reduced to a minimum at this point, and except for occasional
storm flows, only enough flow is maintained to supply the Mexican Treaty
requirements. The TDS fluctuates somewhat because of change of demand as
compared with volumes of return fiows~ This problem is of International
concern, and some relief has been afforded by the construction of the
Wellton- Mohawk drain extension shown on Plate 2. The final solution of
this problem is of total basin concern, and the entire burden should not
be placed on the local area or on one State of the basin.
4. Quality of Water at Imperial Dam - The TDS of the water reaching
Imperial Dam shows a steady increase. A substantial part of this Increase
is due to agricultural drainage from the Colorado River Indian Reservation,
the Palo Verde Valley, and probably some from the Cibola Valley~ Reduced
flow in the river due to consumptive use and diversions out of the basin
has substantially reduced the assimilative and dilution capacity of the
stream. A part of the increased TDS can be traced to evaporation from
the water surface and phreatophyte growth along the river. The TDS record
is shown in Exhibit 10 0
A. The Main Stem of the Gila River: The gross watershed of the Gila
River System upstream of Dome, Arizona ( 12 miles upstream of the confluence
with the Colorado River) is approximately 57: 477 square miles, excluding
all closed basins upstream. The main stem of the Gila River upstream of
the U. S~ Geological Survey gaging station in New Mexico near Virden
( 16 miles upstream of the New Mexico- Arizona border) has a drainage area of
3,203 square miles. There are no major control structures on the Gila River
in New Mexico, although Hooker Dam has been proposed. The watershed of the
Gila River System in Arizona is shown in Plate 4.
The Gila River enters Arizona near Duncan, flows through Duncan Valley,
is joined by the San Francisco River near Clifton, and flows westward
through Safford Valley to the San Carlos Reservoir behind Coolidge Dam,
the first major control structure on the river. Vater released from
Coolidge Dam flows westward through remote mountain country until it
reaches the San Pedro Valley where the San Pedro River joins the Gila
River. The combined rivers flow through more remote mountains past the
Buttes Damsite to Ashurst- Hayden Dam near Florence.
All of the water reaching Ashurst- Hayden Dam, with the exception of rare
flood flows, are diverted for beneficial use in the San Carlos Project.
Sluicing of the heavy sediment load at Ashurst- Hayden Dam has been replaced
by mechanical sediment removal equipment, so there is essentially no flow
in the Gila River below this dam. All of the water in the mainstream Gila
River, from a point ten mi les upstream from the eastern boundary of Arizona
to the Gila Crossing ( near the confluence of the Salt and Gila Rivers), is
allocated under the Globe Equity No. 59 Decree of June 29, 1935 ( 17). The
provisions of that Decree are enforced by the Gila Water Commissioner appointed
by the Arizona District Court of the United States.
The Gila River below Ashurst- Hayden Dam is situated in an arid desert
area. Intense desert storms contribute some flow to the Gila River at infrequent
intervals for short periods of time. There are small diversion
dams near Olberg ( Sacaton Diversion Dam) and Gila Crossing before the Salt
River joins the Gila River near Avondale. Annual flow data for Water Year
1965 at various points on the Gila River are sh0wn on Plate 5.
The Salt River System contributes very little water to the Gila River because
of upstream use. This facet is discussed in Reg. 6- 2- 2.2 B under
tributaries to the Gila River.
Almost all of the water which accumulates in the Gila River below AshurstHayden
Dam is diverted at the Buckeye Irrigation Company diversion dam, the
Arlington Canal Company diversion works, and at Gillespie Dam for irrigation.
Except for storm flows and gate leakage at the dam, there is no surface flow
between Gillespie Dam and Painted Rock Dam approximately 60 miles downstream.
Painted Rock Dam was completed in 1959 as a flood control dam to protect
the Yuma area from flash floods following intense desert rainstorms.
Below Painted Rock Dam~ the Gila River channel is dry except for occasional
storm flows. Irrigation drainage water from the Wellton- Mohawk
Valley has contributed some fiow at Dome ( 12 miles upstream from the confluence
of the Gila River with the Colorado River) in the past, but a new
drainage system completed in 1961 has steadily decreased the contribution.
In addition to the annual flow data for Water Year 1965 presented in
Plate 5, flow data at various points in the Gila River System is given in
Exhibit 22.
B. Tributaries to the Gila River: There are numerous tributaries to
the Gila River in the 508 rive- r- miles between the New Mexico- Arizona
- 18-
~ o
- t- Ex i st i ng Dam
- f- Proposed Dam
--- ARIZONA------------ t
, o
, 0
1 0
-~~~ < Ix Z llJ
Oo:; E
ex:: z 0 o U
- aN:: xw
ex:: : a:
+-. -~
Calva( 4665)[ 90,960J
San Carlos Res. ( 4690)[- 34,830J
Coo I i dge Dam
San Pedro R. ( 4710)[ 1& ! 40
San Simon R. ( 4570)[ 7 550J
Virden( 4320)[ 96,290J
[ 18,840J D- u- ncan- Virde- n - Valley ( 4325)
( 4685) [ 24,550_
San Carlos R.
Va Iley
( 4490)
P~ oenix
-) w L __ . J>
Glenwood( 4440)[ 41,010J
Salt River
( j)
r » 1J 5195)[ 804J ::: 0
< r Painted Rock Dam rn
Hassayampa R. ( 5198)[ 882J ::: 0 » ( J) 5155)[ 22,050J Dome( 5205)[ 279J (- J<) - l - of
rado River ARIZ NA ARIZONA rn 3:: CAL IFORN IA Imperial Dam I MEXICO 111 · : 0 Dam (( J))
- lX rn
3:: eUx:::: wE - » l U1 -
Granite Reef
See Plate
~ Roosevelt
~ Horse Mesa
00 Mormon Flat - 0)
o ~ Stewart Mountain
~ + 1----
( 5\ 13) 625 600
( 5i38)
Verde River
'--....-~~ w. J~~~~'+ thS~ a!.!. inw.. F.!.. r2. an~ cs~~ ic~ o~~~:;:;'::;';~~~":":; M'"
~ ~~ rseShoe
~ ,
~ = Bart lett
( 4320) USGS Gage Station
( 9- before each no.)
[ 279}- Flow at Station
Acre- feet/ year
~ Existing Dam
~ Proposed Dam
boundary,!~ nd the confluence with the Colorado River near Yuma. Flow data
for the m; aJor tributaries is given for Water Year 1965 on Plate 5, and expanded
flow data is presented in Exhibit 22. Descriptions of the significant
tributaries are as follows:
1. San Francisco River - The San Francisco River has Its headwaters
in Arizona near Alpine. It flows eastward through Luna lake into New Mexico
and back into Arizona northeast of Clifton. The gross drainage area of the
San Francisco River above the gaging station near Clifton ( 9.9 miles upstream
from mouth) is 2,766 square miles. The salt load of the San Francisco
River varies with the flow rate. Available data shows the TOS ( Total
Dissolved Solids) load ranges from 200 to 1200 mg/ l. Diversions are made
for mining, municipal and irrigation use upstream of the confluence with
the Gila River. The Clifton Hot Springs is a source of salt which degrades
the water quality of the river.
2. Eagle Creek - Eagle Creek drains a 377 square mt Ie area on the
north side of the Gila RIver. In addition, water is pumped into Eagle
Creek from the Black River in the Salt River watershed. A large portion
of the water flowing in Eagle Creek is diverted by pumping for industrial
and municipal use in and near Morenci and Clifton. The water Is of excellent
qual ity.
3. San Simon River - The San Simon River drains a 2,192 square mile
area in the San Simon Valley. There are some minor intermittent flows from
New Mexico into the valley. The San Simon River joins the Gila River between
Solomon and Safford. There is very little rainfall in this drainage
basin, and the river usually flows only during storm periods, and available
data shows a TDS load of 500 to 900 mg/ l in the floodwater. The sediment
load is also high. Flood flows are partly regulated by six flood control
detention structures.
4. San Carlos River - The San Carlos River drains a 1,027 square
mile area north of San Carlos Reservoir. Although the 36- year average
discharge of this tributary is 32,070 acre- feet per year, there are periods
of no flow each year. The meager data on quality Indicates fair
quality during high flows to poor quality during low flows.
5. San Pedro River - The San Pedro River drains an area of 4,449
square miles, of which 696 square miles are in Mexico. The first gaging
station in Arizona is near palominas, approximately 4.5 miles from the
Arizona- Mexico border. The total flow at this point has averaged 21,000
acre- feet per year for the 23- year record, but the flow rate has varied
from 0 to 22,000 cubic feet per second ( cfs). Diversions above Charleston,
where a dam is proposed as a part of the Central Arizona Project, are
mostly by groundwater pumping. Downstream of Charleston, surface flow
decreases. Diversions, both by surface flow and groundwater pumping, are
made for irrigation, domestic and industrial use. The San Pedro River joins
the Gila River near Winkelman. Quality records on the San Pedro River are
meager. Records of quality on the Gila River at Kelvin, 17 miles downstream
of the confluence is the best index available.
6. Mineral Creek - Mineral Creek drains approximately 98 square
"' 19-
miles of area north of the Gila River at Kelvin. This creek was named
Mineral Cre~ k in 1846 by a mil itary scouting party because of its saline
qual i, tiles and brown color. The flow varies from zero to approximately
30,000 cfs. There is one flood control structure which has silted up and
is no longer effective. Another structure is being considered. A large
ope~ pit copper mine is situated on this creek) and the natural channel is
be. ing replaced to ~ l1ow for mine expansion.
7. Queen Creek - Queen Creek drains a desert foothills area north
of the Gila River) and flow is restricted to periods of heavy rainfall,
usually duri~ g the summer and fall. The flow is controlled by Whitlow
Dam, and it is doubtful if any surface flow would ever reach the Gila River.
$. S~ nta Cruz River - The Santa Cruz River drains 8,581 square miles
before it reaches the Gila River near Laveen. There is a 348 square mile
drainage area in Mexico. The 23- year record shows an average annual flow
at them~ uth () f 14,550 acre- feet, with no flow at all for the majority of
the time •.; There was a measured flow during 54 days of the 1965 water year,
and 60% q~ t. he flow occurred during 3 days. There are many diversions,
most ly by groundwater pumpi ng, for i rri gat ion, mun ic ipa 1 and industr ia 1 u'se.
9. Salt River System - The Salt River System physically joins the
Gila River System west of Laveen. The Salt River System includes the Salt
and Verde River$ and their tributaries. The Salt and Verde River flow is
contrplledby dams except for periods of extreme flooding ( the capacity has
been.. exceeded only twice since 1941), and essentially all of the flow is
diverted for irrigation, municipal and industrial use at Granite Reef
Diversion Oam ea~ t of Phoenix. The Salt River Valley area, including
parts of the water distribution system, is shown on Plate 6. There are
13,000 square miles of drainage area above Granite Reef Dam. Hater it,
the Salt River System is adjudicated under various court decrees ( 18 » )
( 23), ( 24).
There is very I ittle contribution of surface water to the Gila River
System . by th, e Salt River System. Irrigation return flow, mostly excess diversion,
' is utilized in the immediate area. There is considerable groundwater
pumping in the area. There is a sewage effluent flow to the Salt
River from Phoenix) and complete reclamation of this sewage effluent for
reuse is being studied. This effluent is being delivered by the Buckeye
IrrigatJon Company for i. rrigation of non- edible crops.
10~ . AguaFria River - The Aqua Fria River drains an area ofl, 459
square mi les upstream of Waddell Dam. Except for flood flows, all of the
water is diverted for irrigation use by the Maricopa County Municipal Water
Conservation District No. I before it reaches the Gila River. The average
flow for the 37- year record period is 59,440 acre- feet per year.
11. . Hassayampa River - The Hassayampa River drai ns an area of 1,470
square miles before it reaches the Gila River upstream of Gillespie Dam.
The average flow for the 19- year record at Box Damsite near Wickenburg is
7,820 acre- feet per year, with many periods of no flow. There are diversions
for irrigation and mining operations along the river. The river
below WLckenburg is alternately wet and dry, and most diversions are . by
,- 20-
groundwater pumping. Flow records at the confluence with the Gila River
are very poor, but the total flow in the Gila as measured at Gillespie Dam
indicates negligible contribution from the Hassayampa.
12. Centennial Wash - Centennial Wash joins the Gila River just upstream
of Gillespie Dam. Flow consists of storm runoff, and the record is
extremely poor.
13. Miscellaneous Tributaries - There are numerous small tributaries
to the Gila River, most of them intermittent in flow~ It; s beyond the
scope of this policy document to discuss each of them.
c. History of the Gila River Basin: Part of the area of the Gila River
Basin was ceded to the United States in 1848 after the Mexican War and the
southern area was included in the Gadsden Purchase of 1853. In 1870, valuable
mineral deposits were found in the area of Clifton, and this area is
now one of the most important copper producing areas in the United States.
The first irrigation of the land in the basin above the Coolidge Dam
area was begun about 1872 by Mexican immigrants and Mormon pioneers in the
Safford Valley, and irrigation in the Duncan- Virden valley followed shortly.
Below the Coolidge Dam area~ early development centered around agriculture.
The Hohokam Indians irrigated lands more than a thousand years ago. This
civilization vanished. Irrigation practices were resumed in the lower Gila
and Salt River Valleys by subsequent Indian inhabitants at dates unknown and
by non- Indian settlers in the 1860' s. Varying flows made irrigated agriculture
a very risky affair, and storage systems were planned. Picacho
Reservoir was built for irrigation storage water in 1890. The Federal
Reclamation Act of 1902 paved the way for construction of many more storage
dams for irrigation water. The Salt River Valley Water Users' Association,
the first organization of its kind formed to take advantage of the act, was
incorporated in 1903. Roosevelt Dam on the Salt River was begun in 1905
and completed in 1911. More dams on the Salt and Verde Rivers followed.
Coolidge Dam on the Gila River was completed in 1928 by the Bureau of Indian
Affairs. The Buckeye Canal Company was formed and the first 5 miles of the
diversion canal was constructed in 1885, and the Arlington, Enterprise, and
Citrus Valley diversions and canals were functioning before Gillespie Dam
was constructed. Gillespie Dam on the Gila River was completed as a private
venture in 1921 to irrigate 10,000 acres in the Gila Bend and Theba areas,
but this area has suffered from a shortage of water. The remainder of the
Gila River Valley has sparse irrigation except for the area around Wellton
and Yuma served with Colorado River water.
Pumping of groundwater began in the 1920' s and became widespread throughout
the basin by about 1940 0
The surface storage system was developed primarily for agriculture, but
domestic and industrial needs are now also supplied. The use of water in
Ari~ ona, especially surface water, is covered by legal water rights. Expanding
population and changes from a strictly agricultural and mining economy
have caused many water problems.
D. Major Diversions from the Gila River System: As described in
- 21-
Reg. 6- 2- 2.2 A, all of the water in the mainstream Gila River, from a point
ten miles upstream from the eastern boundary of Arizona to the Gila Crossing
( near the confluence of the Salt and Gila Rivers), is allocated under
the Globe Equity Decree. Diversions from the San Pedro River upstream of
its confluence with the Gila River have not been adjudicated. There are
numerous withdrawals of water from these rivers upstream of Ashurst- Hayden
Dam both by surface diversion and by pumping of groundwater. The Globe
Equity Decree provided for irrigation diversions of 1/ 80 of a cubic foot
per second per acre of land, with a total of 6 acre- feet for each acre annually.
The areas defined by the Globe Equity Decree are chronically and
critically short of water and even supplemental pumping does not add enough
water to the surface diversions to provide an adequate supply to the lands.
The major diversions from the Gila River under the Globe Equity Decree are
as follows:
1. Duncan- Virden Valley - The decreed area for irrigation in this
valley in both New Mexico and Arizona is 8,061 acres. Between 8,000 and
20,000 acre- feet per year has been diverted during the past five years,
and the additional water required has been pumped from the groundwater.
Almost all of the return flow to the river is subsurface.
2. Safford Valley - The decreed area for irrigation in the Safford
Valley is 32,512 acres. Water is diverted through thirteen canal systems,
and supplemental ' dater is diverted by pumping, both from the river and from
the groundwater. The diversion from the river during the last five years
has varied from 39,630 to 104,700 acre- feet per year depending on the river
yield. Most domestic water is supplied by pumping from the groundwater.
3. San Carlos Project - The decreed area for irrigation in this
project is 100; 546 acres. There are two sections to this project-- the
" Indian Landsll and the " Hhite Lands" as given in the Globe Equity Decree.
The acreage is approximately equal. Surface flow is supplemented by pumping
from the groundwater. The diversion from the river has ranged from
42,450 to 247,820 acre- feet per year during the past five years. There is
some storage on the project in the Picacho Reservoir. Domestic needs in
the area are served by pumping from the groundwater.
4. Miscellaneous Diversions - There are numerous diversions for
irrigation,- domestic and- industrial uses along the river. These uses are
covered in the Globe Equity Decree.
Other decrees have adjudicated waters of the Gila River System, and there
are other diversions. Under the Haggard Decree ( 1903), 1,080 acres of
Indian lands at the confluence of the Gila and Salt Rivers were decreed
diversion rights ( 24). Under the Benson- Allison Decree ( 1917), 19,865.5
acres of land served by the Buckeye Canal were decreed diversion rights,
6,033 acres served by smaller canal systems were decreed diversion rights,
and rights of the 1,080 acres of Indian lands were reaffirmed ( 23). The
Arl ington Canal diversion is between the Buckeye Heading and Gillespie Dam.
Diversions at Gillespie Dam were adjudicated to lands of Enterprise Ranch
( Enterprise Canal) and to Gila River Ranches and Narramore Ranch ( Gillespie
Canal), under a 1922 Court Decree.
- 22-
Eo Economy and Natural Resources of the Gila River System: The economy
of the entire area of the Gila River System is limited by the water supply.
The economy and natural resources discussed in Reg. 6- 2- 2.1 H of the
Colorado River apply equally to the Gila River System, and wiTI not be
repeated except to emphasize that the Central Arizona Project is vitally
needed to help sustain the economy and to help reduce the quantity of the
more mineralized groundwater being pumped to supply various needs.
F. Water Quality Considerations: THE QUALITY AND QUANTITY FACTORS OF
IMPOSSIBLE TO SEPARATE THESE PARAMETERS. The flow data on the main stem of
the Gila River and its tributaries for the 1965 Water Year is shown schematically
on Plate 5 and expanded for other years in Exhibit 22 to illustrate
the variable flow parameters.
The variable flow in the Gila River is due mainly to storm runoff which
carries a considerable silt load. Flow from the Gila River is first controlled
at the San Carlos Reservoir which acts as a silt control works.
\ tJater released from Cool idge Dam is relatively clear, but inflovv from the
San Pedro River and other tributaries is uncontrolled and the silt load
at Ashurst- Hayden Dam is again appreciable, causing silt control problems
in the San Carlos Project. The silt load requires constant canal cleaning
and prevents a canal lining program vital to water conservation. Buttes
Dam, when authorized and built, will reduce the silt load in the canals so
that a lining program will be feasible.
The variable flow rates also contribute to the salinity problem. In
general, the salt concentration increases as the flow decreases, but the
watersheds of different tributaries contribute different quantities and
types of salts. To illustrate, the Total Dissolved Sol ids ( TOS) and sodium
concentrations in the Gila River water at Kelvin are plotted against flow
rate in Plate 7 for the 1962 to 1964 period. The different pattern of the
data for the total salt content and single ion content illustrates the
effect of different watersheds on the qual ity of water.
The TOS content of the water entering Arizona in both the Gila and San
Francisco Rivers historically varies between 200 and 500 mg/ l. The fluoride
content has been consistently high, normally above one ( 1) mg/ l even
in periods of high flooding ( 12). The fluoride content of many of the
groundwaters of the entire Gila River Basin is high, probably due to redeposition
of these salts washed downstream from the upper basin. The
groundwater in the Duncan- Virden Valley varies from very low to over 5000
mg/ l of dissolved salts, and some salt load is added to the Gila River
water before it is joined by the San Francisco River.
The Cl ifton- Morenci area contributes considerable salt to the San Francisco
River, some from solution pick- up from the saline soils and some from
the highly mineralized hot springs. Long term continuous data on quality
is not available for this area.
Downstream of the confluence of the Gila and San Francisco Rivers, the
tributaries contain varying salt loads. Eagle and Bonita Creek water contains
about 300 mg/ l of salts. The San Simon River contributes water with
- 23-
a TDS of 500- 900 mg/ I during flood stage. There are some artesian flows
in the Safford Valley which contribute a variety of salts to the Gila River
flow. The gtoundwater in the Safford Valley is generally highly mineral-
:' ", ...., < ized.
The San Carlos Reservoir acts somewhat as an equalizing reservoir for
the salt content of the Gila River water, but downstream flow is again influenced
by hot springs and runoff from other watersheds as seen in Plate
7. By the time the water reaches Kelvin, the TDS load varies between 400
and 2000 mg/ l. Generally speaking, the TOS load is below 1000 mg/ l if the
flow remains above 200 cubic feet per second.
Very little quality data exists for flows below Kelvin. Except for
occasional flood flows, all of the water reaching Ashurst- Hayden Dam ( 19.5
miles below Kelvin) is diverted for use in the San Carlos Project, and there
is no return flow to the river as a surface stream. The proposed Buttes
Dam, in addition to its function as a silt control structure, would contain
the flood flows which enter the Gila below Coolidge Dam, particularly
from the San Pedro River. There is considerable groundwater pumping in the
area, and the Central Arizona Project is needed in this area for supplemental
water and quality control.
The Salt River System waters vary in quality, but not quite as drastically
as the Gila River and its other tributaries. The extensive reservoir
systems on the Salt and Verde Rivers tend to equalize the extremely high
and low salt waters. The TDS of the Salt River below Stewart Mountain Dam
has varied from 361 to 1300 mg/ l during the period of 1950 to 1961•• The
TDS of the Verde River below Bartlett Dam has varied from 158 to 550 mg/ l
during the same period. The quality of water delivered to the users in
the Salt River Valley depends on how much water is available from each of
the rivers. The ratio varies from year to year as seen in Exhibit 22 for
Stations 5020 and 5100.
The surface flow of the Salt River System is not sufficient to satisfy
the needs of the Salt River Valley, and there is considerable groundwater
pumping. The amount pumped in the valley greatly exceeds the annual recharge.
In addition, the groundwater is quite saline in most areas. The
Central Arizona Project is desperately needed in this area to allow for
water importation. Such importation would help with respect to both the
quality and quantity.
The next surface flow in the Gila River is at Gillespie Dam. The TDS
load at this point averages 5,000 to 6,000 mg/ l. This water is diverted
for irrigation purposes. The water usually has a fluoride concentration of
2 to 4 mg/ l.
With the meager amount of quality data available in the Gila River System,
it is difficult to isolate any single source of gross degradation of the
water. It appears that much of the degradation is the result of natural
sources of salinity.
Some drainage water from agricultural facilities downstream of Painted
Rock Dam and occasional floodwaters reach the Colorado River near Yuma.
- 24-
a 0 a
o 0 a
o 0 a
r< I <:: r l!\
o 0 a
o 0 a
o 0 a
r< I <:: r l!\
o 0 0 o 0 0
r< I <:: r l!\
o 0 0 o 0 0
r< I <:: r l!\
1962- 1964
o 0 0
r< I <:: r l!\
o 0 0
r< I <:: r l!\
l- . · • •
eo • • , ., • · · · · • . · · •
, , • •••• .•,• "..'•..•.. · • · 0 , 0 . • . . . • ~
p.. , , . .' . ·
" .. • . · · · . .,. • · · 0 . • . · ·
• .. .
10- • -
~ .. , ·
l. • ••• . · · . . . .
01- .
,, ., • · · , ·
~ . , , ... · • ~ • · • . , • • 10- . • · , . ,,', , .,, . · ·
0 · · .
0", · . .1
i' · • .
a, 300
c. f") o
>--.. J a
c. f)
< l:::
300 f-
~ oo
......... 100
co z .. ::? E: 50
a0 40
The drainage water is now almost completely contained in the concrete lined
drainage channel of the ~' ellton- Mohawk Irrigation and Drainage District.
The effect of this drain is seen in the data for U. S. G. S. Station 5205
( Dome, Arizona) in Exhibit 22. The flow in the Gila River has decreased
to less than an acre- foot per day since Water Year 1963. The subject of
salinity below this point of the Gila River is discussed in the Colorado
River Policy Document. It should be pointed out, however, that rate of
floodwater release from Painted Rock Dam can drastically affect the salinity
problem in the lower Gila and Colorado Rivers. Floodwater has been released
only once since completion of the dam in 1959.
- 25-
- 26-
There is negligible direct use of surface water as a raw domestic source
below the confluence of the Salt and Gila Rivers.
Surface water of the Salt River system is extensively used as a raw
domestic source for the metropolitan Phoenix area,
6- 2- 3
6- 2- 3.1
6- 2- 3.2
6- 2- 3.3
B. Gila River - Diversions for agricultural use are made throughout the
basin. ' Boron content from natural sources limits the use on some crops.
In some cases, the TDS and Sodium percentage also limit crop use.
All of tHe surface waters of Arizona are subject to either the appropriative
rights doctrine or to water use contracts with the Secretary of
the Interior. There are no riparian water rights in Arizona. Some of
Arizona's decreed entitlement to main stem waters of the Colorado River is
not now diverted and is being used by other states until additional Arizona
facil ities are authorized and built. The following beneficial water uses
are being made of waters in the Colorado River and Gila River Basins in
Arizona. This tabulation is not intended to designate order of importance
or rights to such use.
A. Colorado River - Diversions for agricultural use are made throughout
the basTn:- The- major diversions are below Parker Dam. Crops grown include
citrus, vegetables, forage, feed, grains and cotton.
A. Colorado River - The volume used for domestic water is minimal, however,
the use is scattered from Page to Yuma along the Colorado main stem.
There is only one known domestic use of surface flows in the little Colorado
Basin at the present time.
Water for domestic purposes is of prime importance throughout the Arizona
Reach of the Colorado River. Although the application of conventional water
treatment including flocculation, coagulation, filtration and disinfection
to Colorado River water will generally not provide a water meeting the recommended
drinking water standards of the U. S. Public Health Service, such
treatment does provide a water meeting the mandatory requirements of the
drinking water standards. Since a better alternate source of supply is
usually not readily available, Colorado River water is used as a source of
raw domestic water.
B. Gila River - High fluoride content from natural sources restricts
the use of the Gila River above its confluence with the Salt River as a
domestic water source if alternate sources are available. There is some
use of surface water of the Gila River as a raw domestic source. Use of
the water has resulted in mottled teeth in chi Idren, and an alternate
source of water is recommended.
A. Colorado River
- 27-
El. Gila River - Haters are diverted all along the flowing streams for
industrial'purposes such as mining, manufacturing and cooling water.
PROPAGATION OF AQUATIC AND \> fILDUFE RESOURCES
6- 2- 3.4
6- 2- 3.5
1. The Colorado River System contains aquatic and wildlife resources.
Such resources include production of organisms, both plant and animal, that
contribute to the food chain supporting a fish population, and populations
of other animal life including waterfowl and shore birds.
On most of the other tributary streams, the surface flow is so undependable
and variable in quality that domestic water is supplied from groundwater.
Future demands in certain areas are dependent upon augmentation
from outside sources.
A. Colorado River - Industrial uses currently are minor. Major use is
for hydroelectric power generation. Several steam generating plants are
being proposed. ~! ater when diverted through the Central Arizona Project
will be partially used for industrial purposes.
The reach between Imperial and laguna Dams is used primarily as a
silt depository for the desilting works at Imperial Dam and for operational
control. Measures for the protection of aquatic and wildlife
resources in this section will be practiced to the fullest extent possible
consistent with the normal operation of the facility as a desilting
works. Prior to the construction of the Imperial Dam and desilting works,
most of the silt load of the Colorado River flowed through the canal system
onto the irrigated fields, and silt control cost about one mill ion
dollars annually. Although the amount of silt decreased with the completion
of Hoover Dam, channel degradation, bank erosion and storm runoff
still contribute a heavy silt load at Imperial Dam ( about 805,000
tons in calendar year 1965). The bulk of this silt is removed continuously
in six classifier type basins on the California side and by a single
basin with periodic sluicing of silt on the Arizona side of the river.
The sediment from the basins is sluiced downstream to a sediment retention
basin for removal by dredging. Removal of this sediment from the sluiceway
channel is required for satisfactory operation of the desilting basin and
overall sediment control measures at Imperial Dam.
This operation results in a varying but heavy silt deposition in the
area between the dams, and a rapidly varying water depth. The operation
is absolutely essential in maintaining a low silt content water delivery
into the canal systems of both Arizona and California,
2. Water is used in the operation of the National Wildlife Service
Refuges, the Havasu lake, Cibola and Imperial Vildlife Refuges. This water
use is covered by the Arizona vs. talifornia Supreme Court Decree. Consideration
is being given to dedication of a portion of the lower Palo
Verde- Cibola Valley region to waterfowl management purposes, to provide
- 28-
enough buffer lands to protect the waterfowl and to provide for future
related recreational needs.
3. Water is used at Mittry Lake, an Arizona State waterfowl area
in the downstream area from Imperial Dam. A State Wildl ife area is being
farmed for waterfowl habitat preservation and feed in the Cibola Valley.
6- 2- 3.6
6- 2- 3.7
6- 2- 3.8
Future consumptive uses of surface water of the Colorado and Gila Rivers,
other than those specifically mentioned as allocated, are of necessity
restricted until a major water augmentation program is real ized. It is
probable that some uses will have to be replaced by a higher priority use
under due procesS of law with full recognition of legal water rights.
B. Gila River - The Gila River System contains aquatic and wildl ife
resources in most of the flowing streams and impoundments. Such resources
include production of organisms, both plant and animal, that contribute
to the food chain supporting a fish population, and populations of other
animal life, including waterfowl and shore birds.
B. Gila River - The Gila is used for a variety of recreational pursuits,
including primary body contact uses. Some uses are restricted in certain
areas due to confl icting water rights and uses, but are generally available
in most areas in which sufficient flowing or stored water is available.
A. Colorado River - The Colorado main stem is used for a variety of
recreational pursuits, including primary body contact uses, between Page
and Yuma. The remainder of the river and the various tributaries are used
for secondary body contact uses with the exception of some impoundments
which may be used for primary body contact sports.
Specific classification of waters by designation through finite geographic
boundaries cannot be made. The uses of the waters of the State
vary to a much greater extent than they normally do in more humid cl imates.
This is due to the fact that the majority of our streams are intermittent
and nearly all streams having a perennial flow are completely regulated.
Thus varying uses are made of these waters depending upon the amount of
flow available, either from natural precipitation or rei eases from storage.
For example, most releases for agricultural purposes are made on a demand
basis, however when sustained flows are anticipated, plantings of fish may
create a fishery where none normally exists. A delineation of major cold
and warm water fishing areas on interstate waters in Arizona is shown in
Exhibit 23. Nearly all perennial waters are used for recreational pursuits.
Use of surface waters for domestic and industrial purposes are
necessarily I imited to those areas having a dependable supply. Numerous
wells for domestic and industrial suppl ies ~ re located in or adjacent to
the stream bed and are greatly influenced by the surface waters that may
flow sporadically, therefore protection of such suppl ies is essential even
- 29-
though the stream may not properly be classified as a surface water source
of such suppl ies.
All waters of the State governed by this document are protected for
esthetic values. This includes perennial, intermittent and ephemeral
streams, and intermittent lakes.
In view of the present qual ity of Colorado River water and the prospect
of further degradation by upstream development, it is imperative that a
major water augmentation program be institLited for the Colorado River System.
Since this program would entail interstate cooperation and Federal
sponsorsh i p, the efforts of other appropr iate State and Federal agenc ies
are necessary to effectuate it.
The Gila River is completely util ized by consumptive uses at the present
time. A water augmentation program would enhance these waters as well.
Control of natural sources of sal inity and discharge requirements for waste
systems can be used to maintain or improve the present qual ity of the water.
- 3.0-
2. Qual ity requirements for specified uses.
1. The consideration of present conditions and contributing factors, an~
6- 2- 4
6- 2- 4.1
6- 2- 4.2
Although the water qual ity indicators under consideration are numerous,
they may effectively be grouped in:
B. Chemical Characteristics - Discharge from future Upper Basin developments
may increase contributions of chemicals to waters entering Arizona.
In addition, further development in adjacent states could cause the same
problem. Should such occur or threaten, corrective measures would be initially
sought through cooperative efforts with the Basin States.
The need for water conservation in the Southwest indicates that beneficial
reuSe of sewage effluents should be encouraged. The increased
recreational use of the entire area could contribute human pathogens to
offset the effect of the el imination of properly treated effluents. This
objective will be met by establishment of effluent discharge requirements
on sanitary wastes from private and community sewage systems, organic
processing plants, recreational facil ities and boats.
A. Bacteriological - The objective is to keep waters of the State
bacteriologically safe for beneficial uses. The contributory sources of
pathogens are disposals of sanitary wastes from communities, from private
establ ishments, and from boats.
I. Natural sources of sal inity in the Arizona reach of the Colorado
Ri.~ - Some of the natural sources of sal inlty have been enumerated in
previous sections. The Arizona Interstate Stream Commission is currently
funded to conduct a study of the Little Colorado River Basin potential
which includes Blue Springs to ascertain its optimum role in control and
development for the water resources program in Arizona.
Interstate cooperation will be necessary to evaluate and reduce the
sal inity of waters reaching the Colorado River from adjacent states as
covered previously. The soils of the Colorado River Basin closely resemble
the geological formations of their origin, namely igneous, sedimentary
and metamorphic. The silts removed by constant erosion of the upper areas
have been deposited in the Lower Basin to form the great delta of the
Colorado River. These silts contain large quantities of salts such as
sodium, calcium, and magnesium combined with chlorides, carbonate, bicarbonate
and sulfates. Thus the soils of the Colorado River Basin are the
basic source of the sal inity in the water. Only I imited areas have been
leached sufficiently to remove these soluble salts, and most lands of the
Basin must be leached before they will become productive.
Efforts to control the natural sources of salinity between Lees
Ferry and Lake Mead may meet with opposition from certain conservation
groups who have been attacking further development of the Colorado River
in this area. Every effort must be made to reconcile the many differences
of opinion on river development o
Gypsum reefs are quite common in the Lake Mead area, and there is
no feasible method of isolating these areas. Fortunately, they do not
appear to contribute a large amount of total salt as evidenced by U. S. B. R.
reports on Lake Mead and the Colorado River ( 7). The answer could be found
in deposition of silts and/ or precipitation of calcium carbonate as a crust
over the gypsum beds.
2.. Natural sources of salinity in the Gila River drainage ,: if'~ There
are numerous natural sources of salinity in the drainage area •. The
alluvial soils and rocks contain soluble salts. Although this source is
difficult to control, water management and watershed manipulation may help
reduce the effect of this source in the future. Salt springs and salt beds
in the vicinity of rivers and creeks are being sought out ( 13) and methods
of control studied and more work must be done.
3. Agricultural sources of salinity - An operational salt balance
must be established in all agricultural operations. In general, all of
the salt entering the root zone of an agricultural project must be removed
from the area if a sustained operation is to be possible. Failure to resolve
this problem ma~ have contributed to the destruction of great civilizations
in the past~ including the Hohokam Indian civilization in the Salt
River Valley of Arizona a few hundred years ago" \- lith efficient irrigation
practices, about two- thirds of the water applied to crops is removed by
transpiration from the plants, use by the plants, and by evaporation from
the soil itself, concentrating al J the salts originally present in the remaining
one- third of the water. This water must be drained away from the
root zone to prevent salt damage to future crops. Thus agricultural drainage
water will have a higher concentration of dissolved salts or TDS than Is
present in the applied water. It is obvious that the incremental increase
of TDS Tn drainage waters of the lower basin will be much higher than for
a similar operation in the upper basin because of the higher TDS in the
applied water.
The TDS concentration of drainage water resulting from the leaching
of new lands can be higher than the concentration resulting from a salt
balance operation~ The effect, however, diminishes rapidly~
The programs outlined in Reg. 6- 2- 2.1 ( canal I inlng, pipe installation,
land levelling, phreatophyte removal, watershed improvement, etc.)
are the current methods of water conservation which contribute to water
quality enhancement~ These programs should be continued, giving consideration
to their effect on other beneficial uses ( recreation and fish and
wildlife propa9ation)~ New, practical processes for reducing the salinity
of irrigation return flows should be applied as they are developed.
The water tables in the Gila River System are generally quite low,
and there is very little return flow to the rivers by surface drainage systems.
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It should be recognized that such programs, while beneficial in preserving
and enhancing water quantity and quality, may produce undesirable
effects on recreation and wildlife values.
4 0 ~ dustrial sources of sal inity - There is 1ittle sal inity being
discharged into waters of the State as a result of industrial operations.
This salinity can be held to a minimum by proper discharge requirements.
5. Municipal sources of salinity - Salts are added to water used
for domestic purposes o Domestic sewage generally has a TDS increase of
about 300 mgl1 over the supply water. This increase can be attributed to
a number of factors such as, but not limited to human waste, water softener
operation, washing clothes and dishes, garbage disposals, etc. The most
significant increase is in sodium chloride.
Return flows from lawn and garden watering follow the pattern set
forth for agricultural drainage previously discussed.
Light industrial and commercial operations in cities usually contribute
salts to the municipal sewage or to the groundwater eventually returning
to the river q Although the individual contribution may be small,
the collective total can become appreciable, and all sources should be
evaluated for effective control.
6. The total salinity problem - The salts added by the natural
and beneficial use sources listed above combine with diminishing flows due
to consumptive use and diversions out of the Colorado River Basin to present
a serious salinity problem for all of the users of the Colorado River
water downstream of Lake Mead. The Bureau of Reclamation and Geological
Survey are cooperating in an electric analog study of the diversions, use
and returns for the area downstream of Imperial Dam, but this study is
far too limited in scope and tends to convey the idea that the salinity
problem is the responsibility of this one area alone, whereas It is a
total basin problem. This concept of a localized problem as set forth In
Minute 218 ( Exhibit 21) is totally unacceptable to Arizona, and the temporary
alleviation procedure effective until November 16, 1970 must be replaced
by a more acceptable procedure whIch recognizes total basin responsibil
ity. The Council wIll cooperate with the above agencies in working
out a satisfactory policy on salinity control.
A report on the study and suggestions on the problem solution by
the Bureau of Reclamation and the Geological Survey is due on May 16, 1970.
70 Heavy metals and associated chemicals - The concentrations of
these chemicals in waters of the State are historically very low. v! astes
Gontaining these elements are widely scattered and can be controlled by
discharge requirements on the individual waste streamo Each discharge requirement
will be based on appropriate factors such as, but not limited
to the dilution capacity of the stream and beneficial uses of the stream o
The setting of stream standards at USPHS drinking water limits
could be interpreted by a discharger as meaning that he could discharge
these chemicals into the stream up to the limit. In effect, then, stan-
- 32-
dards could be unjustly used to discriminate against downstream users because
there is no dilution capacity left. This problem of apportionment
of dilution capacity of the stream must be solved on an entire basin level
before specific limits can be placed on the Colorado and Gila. This task
is expected to take one to three years.
Until specific limits are set, the policy of the Council through the
State Department of Health is to minimize any discharge of these chemicals
to the river in accqrdance with the Statement of Policy. Generally, industry
is the source of disposals containing these chemicals; and also
generally, these wastes are contained in relatively small volumes of water
which could be economically disposed of elsewhere.
8. Biocides - Biocides have been the subject of much discussion
in the past, and probably will be discussed for many years~ Prudent use
of biocides has enabled our agricultural industry to provide ample food
and fiber products for our high standards of living. Esthetically, we can
have better gardens and a more healthful existence because of biocides.
Uncontrolled use of biocides is not beneficial, and should not be allowed.
Generally speaking, biocides are expansive, and over applications are seldom
made. Discharges of wastes containing biocides from manufacturing and
tank cleaning operations must not be allowed.
More research and study of the cumulative effects of biocides on humans
and wildlife must be made, and appropriate safeguards applied as standards
for the waters of the State.
Types and effects of biocides are too numerous and varied for tabulation~
Further, the intricacies and variations of technical analysis for
biocides presently defy the prescription of anyone or a few tests for their
detection or determination ( 4). Bio- assay tests can be used to establish
allowable limits for biocides.
Application of biocides in agricultural operations which could result
in biocide levels in waters of the State which are deleterious to human,
animal, plant or aquatic life shall be subject to abatement. Mere
detection of a biocide in the water is not cause for abatement.
9< Radioactivity - Radioactivity in waters of the State is contained
within satisfactory limits. There are no wastes containing radioactivity
being discharged into the Arizona reaches~ Future problems will
be controlled by discharge requirements~
lO~ Other chemical characteristics - Boron reduction will be considered
along with reduction of salinity in agricultural return flows o
Eutrophication, although not a major problem at this time, could become
a problem if the nutrient concentration in the water increases. Minimization
of nutrient contributions to the river systems is mandatoryo
Phenols and organic chemical concentrations are not now a problem,
and there are'no known discharges. Any proposed discharges will be sub-
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ject to regulations commensurate with timely technology.,
2. Disposal of sewage effluents outside of the river area can
reduce the total flow of the river and reduce the assimilative capacity
of the river downstream, denying the downstream user of his legal entitlement
to use of the water.
6- 2- 4.3
6- 2- 4.4
4. In view of the fact that water disposed of on land in a bastn
could return to the river underground in worse condition than when " disposed
of', careful consideration of requirements for disposal on land
must be made.
3. When waters containing considerable dissolved salts are being
considered for discharge to the river, total resource effects should be
determined, and the decision should not be made on the basis of the concentration
of the discharge alone. This concept is vital in the conservation
of total water supply in the stream. Unwarranted depletions could
deprive downstream users of valuable rights to water use.
1. Hardness in domestic water is undesirable, and can be removed
by several processes. Ion exchange or precipitation methods can alter the
cation balance of the water to the extent that the change can adversely
affect penetration rates of water in agricultural operations&
The major problem associated with control of pollutants in the waters
of the State is that the method chosen may reduce the quantity of water
available to downstream users, or may adversely affect the user downstream
by a chemical or physical change in the water. Factors such as the following
should be considered in setting numerical stream standards.
B. Investigations - In view of the changing topography and increasing
intensity of multiple use of waters of the State. it is necessary that
periodic investigations be conducted in the river or on the watershed to
remain apprised of the most recent conditions which may degrade water
quality, and which may affect any particular beneficial use of the river
waters. The scope of such investigations will vary from cursory field
inspections to technical studies of water quality conditions o The investigations
will be conducted under the direction of the Council by the
A. Water augmentation - The need of a major water augmentation program
for the waters of the State is immediate. Institution of this important
program requires cooperative actions and representations between local,
state, interstate and federal agencies. The Council and the State Department
of Health will do all that they can to expedite the Institution of
such water augmentation program to improve water quality in the Colorado
and Gila River Systems.
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2. To protect the publ ic health.
General water qual ity objectives are:
6- 2~ 4.5
3. To preclude pollution of the waters of the State.
6- 2- 4.6
C. Coordination with other agencies ~ The Council and the State Department
or Health, in the pursuance of their water quality control activities
will at all times remain in advisement and consultation with the several
interested agencies, and will work cooperatively with these agencies to
produce the most effective water quality control program.
Each beneficial water use req~ ires certain indicators of water quality
as desirable or essential. Pertinent indicators are investigated for
adequate protection of each beneficial use. Water quality objectives
are formulated in consideration of these indicators, and effects upon
the economy of the area which may result from various levels of control.
Where more than one level of an indicator is under consideration in the
protection of various beneficial uses, preferential selection is given
to that level which represents the superior water quality.
Special emphasis will be placed on finding practical means of reducing
the salinity of agricultural drainage water, since this benefi~ ial use
requires that large quantities of water be returned to the river in order
to maintain a salt balance.
State Department of Health staff either alone or in cooperation with other
agencies. However, where specialty is required, the State Department of
Health will either request or contract the necessary services.
In the selection of standards for a particular water quality objective,
consideration must be given to the economic and social effects which may
result therefrom.
1. To provide the highest quality water practicable for all beneficial
The most important water quality indicators for protection of irrigated
agriculture are sal inity, sodium relationships, boron and bicarbonate
effects. These indicators are as follows:
1. Salinity ~ Excessive salinity in the root zone causes adverse
effects upon ptant life) ranging from leaf- burn to death of the plant.
Salinity characteristics of water for agricultural applications are most
effectively indicated by measuring t~ e:
a. Total Dissolved Sol ids ( TOS) , in mg/ l.
b. Electrical Conductivity ( ECxl06), micromhos.
The records indicate some increase of sal inity in Colorado River
water released towards Arizona, as well as continuing increase in total
quantities of salts returned to the main stem from farm drainage on both
sides of the river along the Arizona reach.
The use of waters of the State for irrigation requires special management
for sal inity control. Adequate drainage must be provided, and crop
selection must be I imited to those crops which will tolerate the existing
salt content at the point of use.
TDS I imits for stockwatering are far more I iberal than are those for
irrigation. Therefore, sal inity control is oriented towards irrigation requirements.
2. Sodium relationships - The predominance of sodium salts . in soil
is detrimental to maintenance of proper tilth and structure for agricultural
purposes. High concentrations of sodium in agricultural supply waters
( relative to calcium and magnesium) will cause cationic exchange whereby
sodium will replace calcium and magnesium in the soil. The water qual ity
indicator which expresses the level of sodium, relative to calcium and
magnesium, is called " percent sodium" and is expressed mathematically as
Na x 100
Na+ Ca+ Mg+ K
where the basic constituents are expressed as mill iequiva1ents per 1iter.
The sodium percentage of a water can change as water concentrates
by evaporation. For this reason, the " alkal i factor", or ratio of sodium
to chloride plus sulfate, in mill equivalents per I iter, could be a more
definitive term for sodium hazard, and its use is gaining in popularity.
An alkal i factor of 1.0 or greater represents a " black alkal i" condition
( an excess of bicarbonate over calcium plus magnesium), which is more damaging
than the " white alkal i" which is essentially sodium chloride and sodium
sulfate. An alkal i factor less than 0.70 would be satisfactory for irrigation
use. A lower 1imit of 0.40 to 0.50 would probably be suitable for
the benefit of non- agricultural users.
Percent sodium in Colorado River water ranges from approximately 28
at Lees Ferry to approximately 51 at Imperial Dam. The recommended safe
1imit of this characteristic for continuous appl ications is 50. The
alkal i factor increases from about 0.49 to 0.55 between Lees Ferry and
Imperial Dam. In view of the low soil permeabil ity of many Lower Basin
areas being irrigated with this water, every effort should be made to control
sodium content in Colorado River waters, such that the present level
of this indicator will not be increased at Imperial Dam. Sodium and alka1 i
figures vary widely in the Gila River Basin.
- 36-
- 37-
Similar negative RSC levels are found in Gila River water.
It is recognized that USPHS Standards apply to treated drinking water
RSC Level
- 3.7 meq'll
... · 4. I meq/ l
.. 3.8 meqll
Stat ion
Lees Ferry
Hoover Dam
Imperial Dam
RSC c ( C03 + HC03) - ( Ca + Mg)
3. BoroQ - The symptoms of boron injury, particularly in trees
which are less tolerant to this constituent, are leaf yellowing and burning,
premature leaf drop, and reduced yield. Citrus trees are among the
crops most sensitive to boron. The critical concentration is accepted as
0.4 to 0.5 mg/ I in irrigation waters. Citrus is one of the main crops in
both the Yuma area of Arizona and the Coachella Valley of Cal ifornia.
Both of these areas draw water from Imperial Dam. During 1961.: · , the average
boron content of Colorado River water at Imperial Dam was 0.2 mg/ l and
the maximum content was O. Ll mg/ l.
To protect the extensive citrus industries cited, the qual ity of
Colorado River water at Imperial Dam, as represented by boron concentrations,
must be at least maintained, and this qual ity should be enhanced
if at all possible. Boron concentrations in the Gila varies widely and
this restricts its use for some crops.
4. Bi~ rbonate effects - Bicarbonate in irrigation water adds to
the sodium hazard by precipitating out the calcium and magnesium sal: ts,
with the resultant proportional increase in sodium content. This effect
is usually expressed in terms of the I'residual sodium carbonatel' ( RSC),
defined as
These ionic constituents are expressed as mill iequivalents per I iter.
Waters containing 1.25 - 2.5 meq. per 1iter of RSC are of marginal quality
for irrigation purposes. Waters containing over 2.5 meq. per 1iter of RSC
are not suitable for irrigation purposes~
The RSC levels of Colorado River water in Arizona are as follows
( 1962 water year, the last data available before the fill ing of Lake Powell)
In view of the negative values, it appears that the bicarbonate
level of the waters of the State are well within the safe range for agricultural
The State Department of Health is the unit of State Government with
primary responsibil ity for formulating and enforcing qual ity of water de-l
ivered for domestic purposes. This responsibil ity also includes consideration
of the qual ity of raw water being diverted for domestic use.
The USPHS Drinking Water Standards are appl icable, but I iberal interpretation
must be used because of the high natural sal inity of Arizona waters.
3. Chemical Characteristics - Section 5.21 of the USPHS Drinking
Water Standards ( 9) reads as follows:
All surface waters must receive treatment to be in compliance with
State Department of Health regulations before del ivery to individual domestic
liThe following chemical substances should not be present in a water
supply in excess of the I isted concentrations where, in the judgment of
the Reporting Agency and the Certifying Authority, other more suitable
suppl ies are or can be made available.
Concentrat fon
in mg/ l
( See 5.23)
- 38-
Al kyl Benzene Sul fonate ( ABS) ,. ,. •
Arsenic ( AS) •••••••• ,. •••
Chloride ( Cl) •••••••••••
Copper ( Cu) • • • • • ,. ,. • • • • •
Carbon Chloroform Extract ( CCE) ••
Cyanide ( CN)•••••••••• ,. •
Fluoride ( F)••••••••••••
Iron ( Fe) • • • • • • • • • • • • •
Manganese ( Mn). • • • • •
Nitrate ( N03) ••• ,. •••••••
1. Bacterioloqical Qual itv - Publ ished records show that existing
col iform counts in certain reaches of the Colorado River are appreciable.
Col iform counts at WPSS Stations in the
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