WSP03141

• File Number: 8270.100
• Description: Colorado River Basin Water Quality/Salinity -- Misc Water Quality
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 1/1/1975
• Author: USDOI
• Title: Quality of Water - Colorado River Basin - Progress Report No. 7 - January 1975
• Water Supply Pro - Doc Type: Report/Study

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PART I. r;rRODUCTIO~

A. Authorization for Report

This is the seventh progress report on Quality of Water in the Colo-
rado River Basin. The directive for preparing this and the six previ-
ous reports is contained In three separate public laws. Section IS of
the authorizillR l~gislation for the Colorado River Storage Project and
participating projects, Public La..... ti.85, 84th Congress, Second Session,
April II, 1956, states. "The Secretary of the Interior is directed to
continu... studies and make a report to the Congress And to the States
of the Colorado River Basin on the quality of water of the Colorado
River."

A progress report to comply with Public l..aw 84-485 was in prepara-
tion when the authorizinJ:t legislation for du! San Juan-(h.llll.'l Project am
the :-1avajo Indian Irrigation Project (Public Law 87-483) bec."ime effective
on June 13. 1962, S~ction 15 of this act Sll1tl.'S. "The SecH~tary of the
Interior is directed to continue his studies of the quality of \oater of
tht? Colorado River system. to appraise its suitability for municipcll,
domestic, and industrial use and for irrigation in the various areas in
the United States in ...tlich it is used or proposed to he used, to esti-
mate the efrec t of additional developments involving its !HOrage aoo use
(whether heretofore authorized or contL~plated for authoriz.1tion) on
the remaini~ ,,"t('r available for use in the United States, to study
,Ill possible means of improving the quality of such 100 ler and of allevi-
ating the ill effects of ,,"ter of poor quality. and to report the results
of his studies and est imates to the Eighty-Seventh Congress and every
2 years thereafter ,"

A few weeks later PubI ic L.1W 590. 87th Congress, Second Session,
....hieh authorized the Fryingpan-Arkansas Project, ,,"s p<1ssed ..nth a simi-
lar section pertaining to quality of wter reports, This public law.
ho~ver, stipulated that January 3, 1963. \oOuld be the submission date
for the initial report am that the reports should be submitted every
2 yenrs thereaftf:"r.

B. Previous Repor ts

A series of six reports starting Ioo'ith the 1963 (-dition have been
prepared prior to this report. Each succeedil'l$l: report updated the pre-
vious report and added chan~es which occurred within the 2-year inter-
val.

In addition to including 2 more years of record, the major chan~es
in this report from the January 1973 report are as follo....s: (1) transfer-
rtn~ that part of the future estimated depletions that actually occurred

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