San Luis Valley Faces Unprecedented Pressure around Its Water

Published online: Sep 01, 2021 Articles, Irrigation Mark Obmascik
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Source: The Colorado Sun

They all remember when the San Luis Valley brimmed with water.

South of San Luis, Ronda Lobato raced the rising floodwaters in San Francisco Creek every spring to fill sandbags that protected her grandparents’ farm. 

North of Center, potato farmer Sheldon Rockey faced so much spring mud that he had to learn to extract his stuck tractor. 

Outside Monte Vista, Tyler Mitchell needed only a hand shovel on the family farm near Monte Vista to reach shallow underground flows in the Valley’s once-abundant water table. 

Today, those tales of plentiful water seem like a distant mirage. Ten of the past 11 years have delivered below-average snowpacks for the upper Rio Grande basin, with this year’s snowpack measuring just 58% of normal at the key May 1 measurement. All but one of the main local reservoirs were less than half-filled.

Farmers face significant cutbacks from wells now and likely from river flows and irrigation ditches later this season.

Against this stark backdrop of drought, three other vast changes loom. 

The biggest is a state court judgment that came after decades of excessive well pumping by valley farmers and ranchers. Local irrigators now must restore 400,000 acre feet of water – more than 1.3 million people in metro Denver use in an entire year – to Valley groundwater systems within 10 years. 

A second challenge is a plan by former Gov. Bill Owens and a metro Denver business group to pump and divert additional deep groundwater from the San Luis Valley to new buyers outside the San Luis Valley, likely on the Colorado Front Range. 

And the third long-term issue is a forecast for flows to be reduced even further, perhaps as much as 30 percent, because of climate change, according to Colorado’s Rio Grande Implementation Plan. 

Buffeted by drought, court orders, climate change, and Front Range diversion plans, the water supply of the San Luis Valley faces pressure as never before. 

Shortages loom. Cuts seem inevitable.

“Our demand for water has far exceeded our supply for years, and now our supply is in a 20-year downward trend,” said state Sen. Cleave Simpson, general manager of the Rio Grande Water Conservation District. “We keep facing drought after drought. The sense of urgency continues to build.”

It all threatens the way of life for the 46,000 residents of the San Luis Valley, where agriculture is the driving economic force. Farming and ranching account for $340 million of sales each year while providing 18% of the region’s jobs. That puts agriculture behind only the government as a source of local employment. About one of every three dollars of basic income in the San Luis Valley comes from agriculture. 

The San Luis Valley is the nation’s No. 5 producer of potatoes – behind only the states of Idaho, Washington, Wisconsin, and Oregon – and a leading supplier of quinoa and alfalfa hay. (The Colorado Potato Administrative Committee says the San Luis Valley is the No. 2 producer in the U.S. for fresh potatoes.) 

In a region long beset with poverty – one of every four Valley residents is impoverished, nearly double the statewide rate – farming and ranching have offered one economic success story. In Saguache County, the annual net income, or profit, per farm was $113,000, says the US Department of Agriculture census. Net income per farm in Rio Grande County was $105,000. 

But all those jobs, all that money, hinge on one thing: an ample and dependable water supply.

“The climate of the San Luis Valley is arid, and a successful agricultural economy would not be possible without irrigation,” says the U.S. Geological Survey.

Average annual precipitation on the Valley floor is 7 to 10 inches, but potatoes, for example, need an additional 14 to 17 inches of irrigation water during the growing season. Alfalfa hay, the Valley’s top crop by acreage, requires up to 24 inches for a crop. 

This adds up to an enormous thirst. According to state water engineers, San Luis Valley agriculture accounts for 810,000 acre feet of consumptive water use per year. 

By contrast, Denver Water needs only 247,000 acre feet of water to supply the 1.3 million people within its city and suburban service boundaries. 

In other words, metro Denver requires only one third as much water as the San Luis Valley to produce a gross domestic product 60 times greater – a $202 billion annual economy vs. a $3.3 billion economy. 

Because the San Luis Valley has so much water being put to comparatively low economic use, metro Denver water developers continue to focus a covetous eye on Rio Grande diversions. 

After the AWDI proposals of the 1980s and the Gary Boyce plan of the 1990s, the Gov. Bill Owens-backed Renewable Water Resources proposal is the latest push to take advantage of relatively low prices to pipe water out of the San Luis Valley.

In the crosshairs is one of the oldest agricultural traditions and cultures in Colorado.

The first surface water right in Colorado, appropriated in 1852, is the People’s Ditch near San Luis. With a series of community irrigation canals called acequias, Hispanic settlers soon started growing food in the high desert with water from the Conejos, Rio Grande, Alamosa, Culebra, San Luis, Saguache, Carnero, and Trinchera, among other rivers and creeks. 

By the 1870s, as much as 50,000 acres in the San Luis Valley was irrigated. After the arrival of the Denver and Rio Grande Railroad, that number soared to 400,000 acres by the 1880s. By 1900, demand for water in several valley streams already outstripped the natural supply.

Farmers responded by building reservoirs, and, especially, digging wells. By the time of World War I, the San Luis Valley was home to at least 5,000 groundwater wells. The rush was on. Underground supplies seemed endless.

Until they weren’t. In 1972, Colorado water officials ordered a moratorium on construction of new wells in most of the valley, and then ended new appropriations of groundwater in the rest of the valley in 1981, which was one of the worst snowpack years on record, with just 11% of normal on May 1.

Luckily, that one terrible year of drought in 1981 was followed by six successive years of some of the best snowpacks in the recorded history of the Rio Grande Basin. From 1982-1987, few worried much about groundwater because the rivers were flooding. 

Another run of giant snowpacks in the mid-1990s helped to keep the pressure off groundwater pumping – while helping to build the memories of valley residents like Ronda Lobato, Sheldon Rockey, and Tyler Mitchell.

“I remember the snowbanks being bigger than me – the winters were so long and cold,” said Lobato, whose aunt and uncle lived along San Francisco Creek. “When the runoff came, we had to fill sandbags to protect against flooding. Today there is no water in San Francisco Creek. It doesn’t run at all.”

Farming is never easy, but water shortages make it even tougher, said Tyler Mitchell.

“I remember as a kid being able to dig with a shovel to find water. Now I might have to go 30 feet to find it,” said Mitchell, whose family runs 18 center pivot irrigation rigs. “The ditch water used to go all summer long. Now we’re lucky to get one month, and some ditches do only a few weeks. We don’t have enough surface water to grow cash-value crops every year.”

The mid-1990s were the heyday of San Luis Valley agriculture, said potato grower Sheldon Rockey, and that era changed the way of thinking for a generation of farmers.

“I remember when the river flooded three years in a row. I got the tractor stuck in the mud,” Rockey said. “There was a lot of money made without worrying much about water. The issue with the older crowd of farmers is that they were so successful for so long. Now that we’re in drought, it’s hard to change your thinking.”

The bountiful water years of the 1980s and 1990s in the San Luis Valley have flipped the typical generational divide in farming. Because they lived through the wettest times, the older farmers tend to have a brighter view than the younger farmers, local agricultural officials say.

“Farming is an optimistic profession,” said Heather Dutton, manager of the San Luis Valley Water Conservancy District and Rio Grande Basin representative on the Colorado Water Conservation Board. “People my father’s age have seen farming here at its best, when we had giant years for water. But the data and science don’t give me many reasons to think those days will come back around. 

“If the big water years do come back, that would be tremendous. But I don’t want us to ignore the freight train coming at us right now.”

That train began blasting its horn about 20 years ago. 

State water engineers long had been concerned about well-pumping by valley irrigators, but the connection between groundwater and surface water was not clearly understood. Starting in January 1976, engineers began monitoring the level of valley aquifers. Groundwater declined steadily but gradually, which led to the state moratoriums on drilling.

However, 2002 was the driest on record for the Rio Grande Basin, with a May snowpack of just 6%. With little available surface water, valley irrigators turned underground for supplies.

The result: In just one year, engineers recorded a 400,000 acre foot drop in Valley aquifers. That is a huge amount of water – a single acre-foot is enough to support two families of four people for a year.

In response to the vast agricultural overpumping came a flurry of laws, regulations, and court actions. 

For the past decade, valley irrigators have been under a court order to maintain a sustainable aquifer system. That means restoring at least 400,000 acre feet to underground supplies, officials say. (Engineering studies say the unconfined aquifer actually has been drained by as much as 1 million acre-feet since 1976.)

Little progress has been made to return that water in the past 10 years. Now irrigators face a 2031 deadline to repay the water debt. 

Still, 5,000 irrigation wells continue to pump in the valley, including 3,000 in the key Subdistrict 1 north of Monte Vista and west of Hooper. 

The $426,000 state Rio Grande Implementation Plan was blunt:  “Because the sustained and lingering drought since 2002 has not been matched with a decline in agricultural consumptive use, use of the aquifers is unsustainable.”

What local water officials now fear is a replay in the San Luis Valley of what happened to irrigators on the South Platte River, where years of over-pumping by farmers, combined with a resulting state court order, led to the 2006 shutdown of 440 wells and the pumping curtailment of hundreds of others. 

In the San Luis Valley, the clock is ticking. A reckoning awaits.

“Shutting down wells – there are people here who can’t survive that,” said Simpson, the state senator. “We are 10 years into this plan to create and maintain a sustainable aquifer system, but we are not yet back to where we started. There are no easy solutions.”

Scientists say it won’t get any easier. Because of climate change, a study by the Bureau of Reclamation, Sandia National Laboratories, and the U.S. Army Corps of Engineers forecasts even more challenges for water users in the Upper Rio Grande Basin:

  • Flows will decrease by 33 percent by 2100 at the Rio Grande near Del Norte, Conejos River near Mogote, Los Pinos River near Ortiz, and San Antonio River at Ortiz. Flows will decrease by 50 percent at the Rio Grande near Lobatos.
  • Peak river flows will come earlier, shifting from June to May. 
  • Fewer water rights will be served. From 1950 to 1999, the average junior-most water right to be served in June on the Rio Grande was a 1910 priority, but by 2100 it will be an 1890 priority.

“We are an incredible agricultural community, but we don’t have the water supply we used to,” said Dutton, the Rio Grande representative on the Colorado Water Conservation Board. “There are more people who want water than there is water available. We are facing scarcity.”