Drought forces a new era of agricultural water conservation
by Paul Larmer
This winter, our usually quiet Colorado valley -- so quiet that you can hear the wingbeats of the eagles and ravens that pass overhead -- has reverberated with the growls of trackhoes digging trenches across hillsides and irrigated pastures. The activity has nothing to do with oil and gas development, though a proposed sale of federal natural gas leases had many of us wondering how our small rural community would cope with an industrial overlay. Instead, this new activity has everything to do with water: Wielding multimillion-dollar grants from the federal Bureau of Reclamation, two local irrigation companies are replacing their open, dirt-bottomed ditches with plastic pipe.
The purpose of the projects is to reduce the load of salt and selenium that irrigation waters carry off our alkaline soils and into the Colorado River system, but the small farmers and ranchers who grow hay in this high desert are excited for another reason; by eliminating seepage and reducing evaporation, the pipes should deliver more water, up to 40 percent more, according to some projections.
If it snows, that is. As of Feb. 7, the snowpack in our Gunnison River Basin was at 77 percent of normal. That's near where it stood last year, before the spring storms failed to materialize. Many of us managed just a single cutting of hay, as water supplies dried up in July, a month earlier than usual.
Conditions are even worse in the heavily agricultural, mountain-ringed San Luis Valley to our south, the scene of this issue's cover story by HCN Assistant Editor Cally Carswell. That pancake-flat valley literally shimmers with water during good years, and has attracted the attention of thirsty Front Range cities, but, as Carswell reports, a deepening drought and the over-pumping of what were once thought to be limitless aquifers have changed both the valley's physical and political landscape. Export schemes have dissipated like virga, and the San Luis' conservative alfalfa and potato farmers have started to tax and regulate their own water usage. Already the footprint of the valley's agriculture has started to shrink, as farmers fallow more fields in their noteworthy effort to take responsibility for their over-pumping.
They will likely have to get far more aggressive if the current climate trends continue. That's a hard truth much of the irrigated West faces: less water and fewer acres under cultivation.
Of course, efficiency measures can help reduce the pain, but even they come with an aesthetic and ecological cost. Our leaky ditch system sustains thousands of cottonwood trees, willows and green glens of wildlife habitat. These will soon die off, and our piped valley will return to looking more like the high desert that it really is, especially if the snows don't come. As one local said to me, only half-jokingly: "We may have the best pipe system in the world with nothing in it."© High Country News