Low precipitation and heat continue to dry out the West. With nine of the 11 Western states recording average water year-to-date precipitations from 50%-to-80% of normal and record-breaking high temperatures, drought is literally a hot topic. When water is limited, the first thing to consider is how to better conserve the water that you have. Then, investigate alternative water sources.
Prevent evaporation from troughs
On farms and ranches, the water evaporation loss from livestock water troughs numbers in the thousands of gallons per year. In 2015, the Roosevelt Soil and Water Conservation District, headquartered in Portales, New Mexico, tested floating shade balls in livestock water troughs to lessen water evaporation loss. The high-density, UV-stabilized, 4-inch-diameter poly balls are half-filled with water for ballast to prevent them from blowing out of troughs.
To conduct its experiment, the Roosevelt Conservation District bought two 8-foot-diameter water troughs. The District filled both troughs with water and added approximately 500 shade balls for 90% coverage in one trough, and left the other trough open. For a year, from September 2015 to September 2015, the Conservation District measured weekly the water level and temperature in both tanks.
“In our test, the 8-foot trough, which was covered 90% by shade balls, lost 489 gallons to evaporation over a year,” says Quentin Carnes, a rancher and District supervisor. “The 8-foot tub that was not covered by shade balls lost 2,159 gallons of water to evaporation.” The District calculated the evaporation of a 20-foot trough — commonly used in the Portales area — at 16,280 gallons per year uncovered and only 3,687 gallons when 90% covered with shade balls. The shade balls, on both the 8-foot trough and 20-foot trough, conserve 78% of water from evaporation loss.
Shade balls also provide other financial and livestock health benefits. “In our country,” Carnes explains, “a lot of the windmills only put out 3-to-4 pints of water per minute. Many ranchers haul water to supplement the windmills. Several ranchers have covered the windmill-fed troughs with shade balls. The difference in evaporation rate eliminates the ranchers from hauling water. When it’s a 106-degree day with a 25-mph wind whipping across a tank, a lot of evaporation occurs.”
Ranchers have observed that the shade balls markedly decrease the algae and moss growth in water troughs, because the balls block sunlight from heating the water. The cleaner water benefits livestock health and terminated the clogging of pipelines, which pump water to individual drinkers, by moss and algae. Additionally, it saves the water that ranchers formerly utilized to flush out the plugged pipelines. Carnes says that some ranchers also have dissolved solids, such as calcium and gypsum deposits, stopping up their pipelines. The shade balls, and the resulting decreased water evaporation, decreased the frequency of pipelines blocked by hard water deposits, too.
Ranchers extend the District’s shade ball experiment. “One astute cattleman had two pastures about the same size and with the same type of grass,” Carnes says. “He put the same amount of cattle on each place. He placed shade balls in one trough and left the other uncovered. He ended up having to haul water to supplementally fill the uncovered trough. Then, when he shipped, the cattle on the place with the shade ball trough gained a quarter pound a month more than the open-trough cattle. He attributed the weight difference to the shade balls. The cattle that drank from the shade ball trough drank more water because it was cooler, cleaner water. The next year, he covered both troughs with shade balls.”
In winter, the shade balls prevent thick ice from forming on water troughs. The balls’ black coloring absorbs heat and their floating agitates the water surface. “In our country, the lows are 16-to-18 degrees at night,” Carnes says. “With sunshine, by 9 o’clock in the morning, the cows have pushed the ice in and are drinking.”
The company from which the District sources the shade balls requires a minimum order of two semi-loads. That’s 104,000 shade balls. It takes approximately 500 shade balls to cover an 8-foot trough and 3,140 to cover a 20-foot trough. The District offers the shade balls in lots of 1,000 or 500. “We now sell shade balls across New Mexico and outside of the state,” Carnes says. “We started this project for water conservation. We found the shade balls also decrease labor and increase cattle health.”
Produced water for ag
You can’t make water, but produced water — a type of wastewater — can be treated for agriculture use. Produced water is present in the underground formation and is “co-produced” when drilling occurs for oil and natural gas. The extraction industry either re-injects the produced water, or they impound it in an evaporation pond.
“Produced water is complex and distinct from other types of wastewater, such as municipal,” explains Jonathan Brant, professor and director of the University of Wyoming Center of Excellence in Produced Water Management. “Produced water can contain lots of salts, residual hydrocarbons and organics. Wyoming is a naturally dry state. There’s a lot of competition for freshwater resources. If a rancher or farmer had a drought-proof, consistent supply of water, such as produced water, it would lower the risk in agriculture.”
Extensive research and technological innovation has developed compact water systems capable of treating produced water for ag use. Produced water must be treated fastidiously for any recycled use. “If there is a missed step in the treatment process,” Brant cautions, “you risk ruining your fields. About 15 years ago there was a coal boom here in Wyoming, and lots of coal bed methane water with high alkalinity. A simple pH adjustment burns the alkalinity out in treatment. Farmers used the treated coal bed water to irrigate. Then, a batch of water had the incorrect sodium absorption ratio and some fields were fallowed. Produced water is a great resource, but you have to be really careful about the quality of water coming out of a treatment system.”
Alongside treatment, water quality monitoring techniques have been developed for the safe re-use of produced water. Brant recommends monitoring protocol that tests water during and after treatment, and tests soil and plants after water application. Treatment, monitoring and transportation increases the cost of produced water use over freshwater.
“Water by nature is a very heavy material,” Brant says. “Moving it from one place to another is the greatest expense incurred with produced water. On a cost comparison, freshwater — if a rancher has the water rights and there is water available to fill their allocation — costs less than produced water.”
In Wyoming, produced water belongs to the state — not to the company that co-produced it from the formation. Though the state holds primacy over how produced water is allocated, it currently doesn’t actively manage it. “Many ranchers have oil and gas wells on their land,” Brant says. “The companies either haul off the produced water or impound it onsite. Likely, a company would be more than happy to have a rancher install a small treatment system to re-use the produced water onsite. It would decrease trucking and road maintenance costs for the company.”
The main challenge with using produced water is the liability. “The reason nobody ever wants to do anything with it is because they don't want to be responsible for any poor outcomes,” Brant says. “I think there’s enough oversight capability. We have the knowledge and technology for compact, self-monitoring systems.” As drought deepens across the West, freshwater lessens. Conserving water through preventing evaporation loss on stock tanks and treating wastewater for ag use provides options.