Irrigation in the basin facing change

Posted 4/6/21

At many times in mankind’s history, the changing technology landscape pushed people out of their jobs. For instance, the introduction of automobiles ended the need for a blacksmith shop in …

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Irrigation in the basin facing change


At many times in mankind’s history, the changing technology landscape pushed people out of their jobs. For instance, the introduction of automobiles ended the need for a blacksmith shop in every town.

But at other junctures, the dwindling pool of employees has forced innovations in technology to be more widely used. That is the situation with farmland irrigation in the Big Horn Basin.

Since the area was first settled, the residents worked to create a labyrinth of canals useful for bringing snowmelt water to the thirsty valley. It was used to flood irrigate thousands of acres of beets, beans, hay, pasture and barley. The irrigators who were employed walked or rode horseback along the canals, opening and closing floodgates, moving orange tarp dams to funnel water where it was needed and putting aluminum tubes into clefts in the lateral canal walls to bring moisture to the fields. More recently they rode ATVs. 

But as America changed, so did this corner of Wyoming. Families were smaller, more students sought higher education instead of hands-on jobs, and fewer and fewer individuals, kids or adults, wanted to work in the fields irrigating. 

“Finding labor in general is hard and getting harder,” said Trent Reed, watermaster and general manager for the Shoshone Irrigation District. “And it is a seven-day-a-week job, just like ditch riders.”

Enter overhead irrigation technology. It is easily seen from any highway in the area — those long, arching legs with attached drop hose lines. The system anchors in the center to an underground pipe attached to a canal headgate, piping the water to the central uptake for the waterer, rather than running it down a canal. It circles, or pivots, around that center pipe, powered by electricity, usually, although some may be powered through solar means.

How much water is allocated to a producer is based on the size of the property. The water rights may be sold with the property and increase its value and asking price. In the Shoshone district, the water is doled out at 2 acre feet per 70 acres.

An acre-foot is a volume of water that would cover one acre of ground 1 foot deep. It holds about 43,500 cubic feet or 325,851 gallons.

Reed said a common head of water — what comes down the canal to the gates to each lateral ditch — is about 3 feet.  When that is the case, most producers can take the water they need or want. But the head may drop during peak irrigation season in June and July, and the allotments are more tightly controlled then. 

The producer or an employee of a farm can request a certain allocation for a specific farm unit. If the farm unit is split, say, beets here and barley there, it does not matter to the irrigation district how the water allocation is divided. If a crop is harvested sooner than another, the rest of the water allocated to that field can be diverted without consequence. 

If someone along the district is slurping up more than their fair share of water, though, they will be warned, and if the overuse continues, their headgate may be padlocked until they agree to comply. On the other hand, if a grower has a good relationship with the irrigation district and others on the system, he or she may be allowed to turn on, regulate and shut off their own floodgates.

The water is mostly from melting snow in the mountains, although rainfall may bump the available water as well. Last week, the Shoshone basin stood at 98% of the median snow water equivalent for years in which records have been kept. That means the irrigation season will be about average, although Reed said available water might get a little tight during peak irrigation.

The pivots can use less water per acre than the old canal and tube system, and Reed said there is also a savings in fertilizer costs because that expensive product is more easily retained on the soil under the gentle sprinkle rather than washed away. But the downside of the pivots is that they return very little of the used water to the systems.

“But the pivots may negatively impact our system. We use a lot of return flows,” Reed said. “That’s the wastewater coming off the rows and rerouted back into the laterals.”

Much of that return flow is routed into Bitter Creek and used again around Garland. 

The reasoning behind the majority of those producers who are going to pivot irrigation is because of the savings in the cost of labor, but the changeover is not without its own costs.


(Editor’s note: This piece is part one of a three-part series on the changing face of irrigation in the Powell Valley. The next piece will study the types of pivot systems and how they work.)