Lecture 7 -The Colorado River

Basic Facts and Figures

Introduction

The Colorado River is a small river. It is not one of the 25 largest rivers in the United States, being smaller than such non-notable rivers as the Apalachicola, Mobile and Sacramento. However, it is the most legislated, most debated and most litigated river in the world. It supplies over one half of the water for greater Los Angeles, San Diego and Phoenix, and the water to grow much of America's winter vegetables. It illuminates Las Vegas, Phoenix and large portions of the southwest. More people are probably dependent upon this river than any other river on earth. This is simply a matter of location. It is the only large river that crosses the arid southwestern deserts of the United States, where rapid population growth in urban centers and agricultural expansion in the deserts has created the demand for water.

River Flow Volume, Resource Allocation and Politics

In 1922, then Commerce Secretary Herbert Hoover, chaired the negotiations of the Colorado River Compact, an agreement between the seven Colorado River states (Colorado, Wyoming, New Mexico, Utah, Nevada, Arizona and California) on how to allocate the water of the Colorado River. The states took eleven months to come to the following agreement:

The Colorado River Basin was arbitrarily divided at Lee's Ferry Arizona into two basins:

Upper Basin - 108,000 square miles Lower Basin - 136,000 square miles

At this time, the estimate of average yearly flow in the Colorado River was 17.5 million acre-feet per year by the Bureau of Reclamation. This estimate was based on only 18 years of measurement.

Each basin was allotted 7.5 million acre-feet per year. Mexico was to receive 1.5 million acre-feet per year. The remaining 1 million acre-feet was apportioned to the lower basin as a bonus.

Some Basic Water Numbers

1 ac-ft = 43,560 cubic feet = 325,829 gallons

17.5 million ac-ft = 762.3 billion cubic feet = 5.7 trillion gallons

In 1928 Congress authorized the construction of Hoover Dam and theAll-American Canal. The agreement was ratified by 6 of 7 states -Arizona declined. Five of the ratifying states - Colorado, New Mexico, Nevada, Wyoming and Utah - agreed on the condition that California limit its annual diversion to 4.4 million acre-feet. This is known as the California Limitation Act. The 7.5 million acre-feet for the Lower Basin were allocated as follows:

California - 4.40 million ac-ft

Arizona - 2.80 million ac-ft

Nevada - 0.30 million ac-ft

By 1952 California was taking in excess of 5.3 million ac-ft per year from the Colorado River, significantly above its allocation.

Hoover Dam

Initial excavations were begun on May 16, 1931. The coffer dams were completed in April of 1933, and dam construction commenced. The dam was dedicated on September 20, 1935 and the first power generated in fall of 1936. All for the cost of $48.9 million - on budget and ahead of schedule. The dam was 726 feet high, contained the largest power plant in the world and at that time was perhaps the greatest structure ever built.

Dam was built by a consortium of eight companies who individually had never built or attempted a project anywhere near the size of Hoover Dam. Out of this consortium emerged some of the major construction and engineering companies of the 20th century, including Kaiser, Bechtel, Utah Construction, Morrison-Knudsen, and McDonald and Kahn.

When filled, the reservoir (Lake Mead) extended 110 miles upstream and held more than 25 million ac-ft of water.

Revised Flow Estimates & Politics

There is great danger in basing long term decisions on short term measurements. However, the very nature of politics demands that reality be ignored (check the promises made by both candidates during the last election). The estimates that the average annual flow of the Colorado was 17.5 million ac-ft was based on a very short period oftime - 18 years; a time period characterized by unusually wet weather. By 1950 it had become painfully clear to hydrologists that the average annual flow of the Colorado River was probably 11.7 ac-ft per year, and certainly not over 15 million ac-ft per year. At that time hydrologists realized that there was a shortage of about 5.8million ac-ft per year in the legal allocation of the Colorado River.

By the early 1960s it became apparent to even the politicians thatthere was something terribly wrong with the allocation of Colorado River water. Lower Basin Allocations at that time were:

California 5.362 million ac-ft (usage is 0.932 million ac-ft overits allotment)

Arizona 2.8 million ac-ft

Nevada 0.3 million ac-ft

Mexico 1.5 million ac-ft

Evaporation 1.5 million ac-ft (not anticipated in 1922)

Total 11.462 million ac-ft

Note that the original allocation for the Lower Basin and Mexico was; 1) the original 7.5 million ac-ft, 2) the extra 1 million ac-ft reluctantly allocated to the Lower Basin in 1922, and 3) the 1.5million ac-ft allotted to Mexico; a total of 10 million ac-ft. The Lower Basin is using 1.462 million ac-ft more than its legal allocation. Even if the flow of the Colorado River was 17.5 ac-ft per year, the Upper Basin could not possibly take its rightfully allotted share, as only 6.532 ac-ft remain above the usage of the Lower Basin. Unfortunately the average annual flow of the river is, as previously indicated, only 11.7 to perhaps 12 million ac-ft per year.

What should be even more disturbing to the tax paying public is the fact that by 1958 the Bureau of Reclamation apparently knew that the Colorado River flow was closer to 11.7 million ac-ft per year and definitely not over 15 million ac-ft per year. Yet it appears that no one wants to acknowledge this simple, but important fact.

Consequently, at this time, it appears that the Lower Basin alone could use the entire yearly flow of the Colorado River; leaving nothing for the Upper Basin. It is obvious that this simply will not work, and that there will be a massive short fall in the amount ofwater that can be delivered by the Bureau of Reclamation, promises, and contracts notwithstanding.

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This page was last reviewed on 1/15/03.