Ag water usage is not leading to low river conditions
July 12, 2018
The Cache la Poudre River, The Coloradoan reported, seemed low as a result of agriculture water usage but the hydrological curve may play a larger role than irrigation.
Fred Walker, a retired farmer from Windsor, Colo., said cycles and historical data demonstrate patterns.
The curve is a graph of historic flows that begin in January with low levels. Once April arrives, the river begins to receive snow melt and the levels begin to rise until early June. The volume, or cubic feet per second, peaks, and then falls off dramatically through the fall and winter.
"The shoulder months can move forward or backwards along the curve," Walker said.
“If I decide not to take a shower today to conserve water, that water is sitting in a reservoir because I didn’t take a shower. Next spring, when the snowmelt comes down, you can’t put as much water in that reservoir because I didn’t use it.”
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The water decrees allowing the diversion of water, which are predominantly agricultural but also include the towns of Fort Collins and Greeley, are subject to the demands at the time. This can mean, he said, that low flows can be observed at different times along different portions of the river.
"As our area continues to grow, the shoulder months see more water come down the Poudre and the cities of Greeley and Fort Collins are releasing water for their treatment plants for water for their citizens down here on the plains," he said.
When this is the case, Walker said the water levels see a benefit more than what is historical. In Fort Collins, residents are more likely to see low levels in town due to the diversions being located upstream.
Of the four major irrigation companies on the north side of the Poudre River that divert its water, three divert north of the city while the New Cache la Poudre diverts near Timnath, Colo. The former's diversions add to the flow of water through the city.
In terms of irrigated farmers taking more than their fair share, Walker said the decrees allow only for a finite amount of water to be used.
Matt Makens, a meteorologist with KDVR/KWGN's Pinpoint Weather Team, said the current dry conditions have been persisting since 2010, with 2012 and 2013 also being particularly bad fire years. The years of 2015 and 2016 saw some monsoon flows, spring rains and good snowfall totals, he said, but 2018 is seeing a spike in drought conditions.
"This region, and more notably just east of the Rockies, tend to run on climate regimes, if you will, that run the order of 20 or 30 years," he said. "That's all tied to ocean circulation. Everybody talks about el Nino and la Nina, but there's a couple of other factors that tie into that."
The way, Makens said, that the two cycles, one in the Pacific and one in the Atlantic, interact plays a role in whether cycles will be more likely to be marked by long periods of potential drought or potential years of moisture surplus. In most cases, though, a drought situation is more likely in this region.
SHIFT IN PRECIPITATION PATTERN
Current drought conditions rival those of mid to late 2013, according to Makens. Prior to that, 2006 and 2002-2004 make up the four primary droughts that have occurred since 2000, with the fourth being the one the region is currently experiencing.
"The good telling thing here is that Wyoming has had a relatively good year," he said. "I think we've seen a pattern shift of wetter conditions in Wyoming and north. I think coming up in the late summer and fall and into winter, we'll see that precipitation pattern shift back south."
While Makens said the shifting precipitation pattern may not cover all of Colorado, it is likely to favor southern Wyoming, western Nebraska and western Kansas.
"Most of Colorado should be in better shape as we hit the fall," he said. "It's likely that el Nino will develop and when that's the case, Colorado and a good portion of Wyoming and Nebraska will come away wetter far more often than they will come away drier."
One of the factors to overcoming drought, Makens said, is a good snow season, something Colorado did not have this year.
This year's snow pack, according to Dale Trowbridge, general manager, New Cache la Poudre Irrigating Company, was less than the 30-year average with the May 1 measurement at only 85 percent. Based on that factor, he said, it is reasonable to expect less water to flow through the Poudre.
"Is it lower today than other July 5ths? Probably not," he said.
While there's no doubt that both agriculture and municipalities are diverting water out of the river, one thing he said the municipalities are doing is diverting water to treatment facilities further upstream, creating lower water levels as observed from Fort Collins.
"Ag really isn't switching anything up," he said. "Our ditch company is nearly 150 years old and we're doing what we've been doing for 150 years. Ag is not expanding, our service area is the same as it has been."
July 5 marked the date the New Cache la Poudre Irrigation Company began running water leased from Horsetooth Reservoir so water levels observed in the coming days will be higher. Return flows, he said, also keep the water levels in the river steadier than it used to be.
"There's 75 cubic feet per second in the river today that wouldn't have been there if ag wasn't utilizing that water," he said. "Ag is also creating an advantage."
As nearby cities grow and water demands increase, Trowbridge said increased water storage is the only solution.
"Conservation can't get us to where we need to be," he said. "If I decide not to take a shower today to conserve water, that water is sitting in a reservoir because I didn't take a shower. Next spring, when the snowmelt comes down, you can't put as much water in that reservoir because I didn't use it."
Conserved water needs to be stored somewhere and more storage is necessary, he said. Additionally, once the water leaves the service area, it's gone.
While farmers in northern Colorado debate storage issues and compete with municipalities, farmers and ranchers in southeastern Colorado are exceptionally dry. Gary Fillmore, of Fillmore Ranch in Boone, Colo., said winter snowfall and rainfall together have been nearly nonexistent.
Fillmore said he received a few sprinkles in addition to about 0.2" back in April, leaving him to dry lot cows and contemplating early weaning. His hope is that the cows bred in May will settle despite difficult conditions.
Fillmore will begin weaning some calves in August that he will market as show cattle though he has pushed back his sale date to allow the calves additional time to gain weight.
"We're playing it day by day," he said. "If we can somehow squeak through the summer, then I don't know how we'll make it through this winter with no winter grass."
Fillmore said his hay stockpile is all but depleted and area farmers have been irrigating at 60-65 percent of capacity.
"We'll have to do something," he said. "We'll have to move or sell out."
While Fillmore is able to market some cattle at a premium, replacing those genetics in the form of females is more difficult and costly once conditions allow numbers to again increase.
While the state's major fires have not burned in Fillmore's area, there have been multiple fires that have burned on both sides of his ranch and within less than a mile of his farm ground.
— Gabel is an assistant editor and reporter for The Fence Post. She lives on a farm near Wiggins, Colo., where she and her family raise cattle and show goats.