WSP01896

• File Number: 8278.200
• Description: Title I - Welton - Mowhawk
• Basin: Colorado Mainstem
• Date: 9/1/1972
• Author: C.C. Taybor
• Title: Wellton-Mohawk Drainage and the Mexican Salt Problem
• Water Supply Pro - Doc Type: Publication

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Salinity, Here and There

Now to Figure 13 which shows salinity of water in the Colorado River

at Imperial Dam and in the Intake Canal at Morelos Dam. For Imperial there is

the annual average and the monthly average of the maximum month. Also shown is

the flow of the river at Imperial merely to illustrate the well known fact that

flow effects quality, - inversely. When the flow is high the salinity is low

and when the flow is low the salinity is high, Also I should remind you that

salinity in parts per million is somewhat vague and subject to computation by

four different methods, no two of which are agreed upon by the experts.

The salinity at Morelos Dam, - here must come a qualifying statement,

The records of 1962, 63 and 64 of water quality taken here by engineers of the
Mexican section of IB&WC are in electrical COnductivity at 250C times 10 to the
sixth power. To convert to parts per million I have used a multiplying factor

of 0,674. This is a figure arrived at by the Bureau of Reclamation from lB samples

of Colorado River water taken at Imperial Dam in 1969 and 70. From 22 samples

taken at the Well ton-Mohawk heading from 1966 into 1972 and analysed at the

University of Arizona by the "summation of ions" method, I get a factor of 0,691.
'"
Ingr. Luis Guzman Garduna, in his report to the "Delegacion Mexicana a la Segunda

Reunion Interparliamentaria Mexico-Norteamericana," used 0.64.

The IB&WC reports of 1962, 63, 64, apparently from information provided

by Mexican engineers, gives daily electrical conductivity which, when averaged,

comes out 2581, 2313 and 2427 respectively. When multiplied by 0.674 this results

in 1739, 1559 and 1636 parts per million, But these reports also show tons per

acre foot of 2.03, 1.96 and 1.94 and that can be directly converted to parts per

million by multiplying by 735.5 and we get 1493, 1442 and 1427. My figures are

about 13% higher so I should not be accused of picking out numbers that are too

low. (See Figures 13a, b, c and d).

The graph (Figure 13) shows two figures for 1961; the first and lowest

is 1360 ppm for the entire year including the 40 days before the hellsapoppin'

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