New Slant on Water ConservationEarly last month Ann Clark forwarded me an article titled “Colorado’s San Luis Valley’s Drought.” The subhead read “Ground Water Conservation Works, Hopefully.” Clark is a retired agronomy professor from Ontario’s Guelph University. Clark’s comment, which appeared online on the Canadian Public Radio website, read, “This is a rather remarkable but perhaps inevitable development now taking place in Colorado. A given farmer signs up to permanently take their land out of production to save the water to allow others to farm. (The signed) agreement is permanent – passing to whomever buys the land in future.” I’ll try to hit the high spots of this CPR story, then follow with several of my own comments.

The article read “A 150-year-old San Luis Valley farm stops growing food to save a shrinking water supply. It might be the first deal of its kind in the country.” In this article, author Michael Elizabeth Sakas wrote that the fields would usually be green in early summer, grown lush on a supply of millions of gallons of groundwater pumped to the surface – but now, the fields are brown, cracked and dry. She explained that farmers across the San Luis Valley face a deadline: Their underground water source is drying up from a combination of overuse and a decades-long drought driven by climate change. To restore a balance of supply and demand, farmers across the valley need to drastically cut how much water they pump out of the ground, according to the Colorado Division of Water Resources. If they don’t, the state has threatened to step in and shut off hundreds of wells, which local water managers said would devastate the valley’s ag-driven economy.

In the CPR article Sarah Parmar, director of conservation with Colorado Open Lands, a nonprofit that works to protect land from development, examined the brittle ground and recounted her first visit to this farm during summer 2021. “The farmer had a mix of peas and oats that he was growing, and they were up to his waist,” Parmar said. “It’s definitely a very productive farm.” She said that no food grows there now. The farmer has stopped watering these 1,800 acres. Instead, he’s working with Parmar on a deal to leave that water alone to save the area’s shrinking groundwater supply and keep other farms in operation.

The farmer is on the verge of signing a contract with Parmar to permanently end the use of his water rights to grow food here, and that rule would apply to any future owner of the property. Parmar called the agreement a groundwater conservation easement – and said it could be the first of its kind in the country.

Conservation easements are legal arrangements that typically aim to protect a farm by tying the land and its water rights together so it can’t be divided up and turned into a housing development. In this case, Parmar said the groundwater conservation easement means changing the property’s use to provide a more regional public benefit (i.e., the greater good). Once the agreement is signed, the farmer – who wishes to maintain anonymity while all this legal paperwork is taking place – plans to sell the land to the Rio Grande Water Conservation District, which will work to revegetate the acres with native plants (which require a fraction of the water formerly sopped up peas, oats and alfalfa – the real water guzzler).

This part of Colorado (San Luis Valley) is very dry. Although Sakas’s article didn’t list the annual precipitation statistic, I’m personally acquainted with the Denver/Fort Collins area about 200 miles northeast of the Rio Grande Water District. Those metropolitan areas receive about 10 – 11 inches rainfall equivalent – a lot of it in the form of snow. The vast majority of that state’s agricultural water comes from deep wells. That state’s dairy industry continues to grow largely on the largesse of Mother Nature’s deep well water supply, which is stored hundreds of feet underfoot in the Ogalalla Aquifer.

There are several definitions of the term “dry land farming.” Most of them center on the idea that one year’s precipitation won’t supply enough rainfall to support the crops that the farmer had in mind. So the farmer harvests a crop every other year. The idea here is that vegetation growing during the fallow year must have the soil structure makeup to store what meager rainfall it receives.

The best example of this I encountered long distance as I arranged to purchase organic canola seed, with the idea that oil would be pressed from this brassica grain related to cabbage, cauliflower, etc. The resulting oil we made into biodiesel, and the mash was organic canola meal, a protein supplement for organic livestock. In 2005 I tracked down an organic canola and wheat farmer in southern Saskatchewan named Curtis Hennings. He explained that with only 15 inches annual precipitation – most of his neighbors are irrigating from deep wells – he gets a crop of wheat and/or canola every year.

He said that his rotation consists of canola, fallow, wheat, fallow, with clover interseeded with the wheat. Henning explained that even though his neighbors harvest more grain per acre than he does, on average, his production costs per ton are less than theirs. He said his organic matter (OM) runs in the 3% – 3.5% range while his neighbors’ are half that. Let’s recall here that each 1% increase in OM increases the soil’s moisture storage capacity by about 16,000 – 18,000 gallons/acre. He also told me that the deeper wells go down, the greater the likelihood of different salts entering the water supply. Maybe this is why at some locations with deep well pivot irrigation pronghorn antelope can be seen grazing just outside dark-green disks of alfalfa. Perhaps the sage brush and other native species don’t taste quite as salty.