Letter to the Editor

Prime suspect?

Monday, January 9, 2006

Dear Editor,

In the continuing debate over stream flow depletions, irrigation is the prime suspect, but have you given much thought as to the amount that conservation causes?

Our irrigators are being asked to make up all the stream flow depletions, when they are not responsible for 100 percent of it.

For illustration purposes, let's look at conservation and irrigation (both activities of man) and how they affect stream flow depletions. In the Republican River Basin, there are approximately 1.8 million irrigated acres and approximately 19 million acres in the drainage area and groundwater model domain.

Let's assume that 10 units of water are pumped on one irrigated acre and that this causes a stream flow depletion of one unit. This would mean that irrigation caused 1.8 million units of stream flow depletion. Remember, this is for illustration and may not be the actual results.

Let's assume that 10 units of water falls on an acre as rainfall and one unit of that doesn't get to the river to be counted as stream flow because of conservation.

This would mean that conservation caused 19 million units of stream flow depletion as the rainfall occurs on all areas in the drainage area.

Even if you reduce this to 1/10th of one unit, the stream flow depletion by conservation would be 1.9 million units, which is still more than irrigation causes.

This is just an illustration, but I hope you see the relationship regardless of the numbers used. When you have 10 times the acres, the stream flow depletions still add up very quickly when they cover 19 million acres.

This illustration holds true regardless of whether you are in the Republican River basin, the Platte River Basin or any other basin. There are a lot more acres under conservation practices than there are irrigated acres.

The stream flow depletions by conservation seem to get a free pass as conservation is loved by urban and rural alike and benefits all.

I'm not proposing that we reduce conservation practices. I'm expecting the compact states to have a formula that reflects the legal definition of virgin water supply.

The settlement did not change the definition for virgin water supply -- it is still the water supply within the basin undepleted by the activities of man.

Conservation is an activity of man.

Dale Helms

Holbrook

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