Wasatch Environmental Update for June 21, 2015
By John Worlock, Member, SOC Board of Directors
“Agriculture Water in the Colorado River Basin”
We’ve returned to our study of the recent report from the Bureau of Reclamation on water supply and demand in the Colorado River Basin. This report, known as Moving Forward, is an attempt to address the challenges discovered in the balance between supply and demand. Today we turn our attention to Chapter 4, entitled Agricultural Water Conservation, Productivity and Transfers. This chapter suggests that even in the arid west we will have plenty of water once we learn to use our agricultural water wisely.
Here is the central statistic that suggests that optimism. It is reckoned that 4 % of our water goes for indoor residential use, and another 6 % for outdoor use. Some 8 % goes to industries and institutions. Subtract those numbers from 100 %, and learn that 82 % of our water goes to farms and ranches. We don’t want to say that those guys are actually wasting our precious water, but we have learned that they can, without sacrificing productivity, make better use of it.
Better use of agricultural water will make a bigger impact than residential savings. Let’s say we succeed in our goal of a 25% reduction in residential use. That will result in an 2 1/2 % reduction overall – a achievement that could be reached by an agricultural reduction of only 3 %!
Historically, since agricultural water has been carried in earthen canals, much of the water was lost to seepage and evaporation before arriving at the farm. Consequently, much water conservation has been achieved with transportation by pipes. More can be achieved if the water is delivered overhead by sprinklers, especially if they are controlled electronically to account for the soil’s moisture. Even then, losses occur by evaporation before the water has a chance to reach the growing roots. Additional conservation is possible with so-called drip-irrigation or microsprinklers. We have seen estimates that nearly 95 % of the water can actually reach the plants, whereas older systems may lose nearly half of the water.
The infrastructure to reach these efficiencies is not inexpensive, but it may well be cheaper than the additional dams, pipelines and canals that would be required to bring more water to our farms and cities. Let’s spend some money on water conservation and keep our farmers green!