Arkansas Basin Roundtable meeting recap

Basin roundtable boundaries
Basin roundtable boundaries

From The Pueblo Chieftain (Chris Woodka):

Well associations have boosted the amount of water they intend to use, and a program to augment on-farm irrigation improvements is growing.

“We remain the only basin in Colorado that has regulated irrigation efficiencies,” [Steve] Witte said. “But in the years we have had it, we have increased the acreage in sprinklers and drip irrigation.”

Witte outlined enforcement actions in the Arkansas River basin, noting that violations of well regulations and breaching unsafe or illegal dams occupied his staff’s time last year. In addition, the Division of Water Resources is taking more of a consulting role in water court cases and filing statements of opposition “only if necessary.”

Last year, in 97 cases, the state filed just one statement of opposition, while settling 21 or 50 pending cases it was active in within Division 2, Witte said.

He also reviewed cannabis — hemp or marijuana — requests, noting that 69 growers, mostly in Pueblo County, had filed plans for water through his office.

About the only thing he wasn’t prepared to talk about: New rain barrel legislation that passed the Legislature this year.

The Lower Ark files 2 Rule 10 plans to comply with surface irrigation rules

From The Pueblo Chieftain (Chris Woodka):

Group plans that will help resolve water issues for more than 160 farms were filed this week with the Colorado Department of Water Resources by the Lower Arkansas Valley Water Conservancy District.

Called Rule 10 plans, they give farmers a way to comply with surface irrigation rules put in place in 2010 as a response to on-farm improvements such as sprinklers and drip irrigation. The state went to court to implement the rules to head off future challenges of the Arkansas River Compact by Kansas.

The state must approve the plans and comments are open on them until April 11.

The Lower Ark district filed two plans, one for farmers on the Fort Lyon Canal, the largest ditch in the Arkansas Valley, and another for farmers on other ditches.

The Fort Lyon plan covers 62 farmers and 99 farms. It projects a credit of 639 acre-feet, but because of monthly accounting, will have to provide some replacement water, said Jack Goble, Lower Ark engineer.

The non-Fort Lyon plan covers 46 farmers and 62 farms on 11 ditches: Amity, Baldwin Stubbs, Bessemer, Buffalo, Catlin, Fort Bent, High Line, Holbrook, Lamar, Las Animas Consolidated and Rocky Ford. It projects a credit of 315 acre-feet, but some recharge and replacement water will be provided on a monthly basis.

Among sources of replacement water for the two plans are Lower Ark storage at Lake Pueblo, Fryingpan-Arkansas water, ditch return flows and leased water from Pueblo Water.

Most of the improvements involve sprinklers fed by ponds, and the Lower Ark district sponsored a study over the past three years which showed leakage from ponds is twice the value originally presumed by the state. The new figure, about four inches per day, is incorporated into both plans.

All of the farms are on ditch systems, since water is generally used in rotation.

Straight line diagram of the Lower Arkansas Valley ditches via Headwaters
Straight line diagram of the Lower Arkansas Valley ditches via Headwaters

Pond leakage study pans out — The Pueblo Chieftain

From The Pueblo Chieftain (Chris Woodka):

Farmers said all along that the state undershot the amount of water lost to leakage from irrigation ponds.

The final numbers confirm that suspicion, showing the rate is double the original assumption.

“We’re not going to celebrate until we get it in writing,” said Don McBee, who nevertheless was clearly pleased with the results.

McBee, a Lamar farmer, and his neighbor Dale Mauch challenged the Colorado Division of Water Resources assumption that ponds used to feed irrigation sprinklers leaked only about 2 inches per day. A stipulation to 2010 irrigation improvement rules allowed for the formula to determine depletions from sprinklers to be changed if scientific evidence showed the number was wrong.

McBee and Mauch were members of a panel formed in 2008 to advise State Engineer Dick Wolfe on how the rules would be drafted. From the first meeting, they said the state was underestimating pond leakage. Since then, they have urged more study and conducted tours of ponds for state officials.

A three-year study sponsored by the Lower Arkansas Valley Water Conservancy District concluded that the actual median leakage is more than 4.2 inches per day, regardless of weather conditions.

In fact, the number means farmers on the Fort Lyon Canal could owe very little water to the Arkansas River when the leakage is plugged into the depletion formula, said Jack Goble, engineer for the Lower Ark. “It’s a drastic difference,” Goble told the Lower Ark board this week, showing how the rules would have affected irrigation over the past 20 years. “There are still months when the Fort Lyon owes water, but it’s pretty rare.”

A two-year study last year was only partially accepted by the state because not all meters were properly certified. Interim numbers were adopted for 2015.

The new study includes data from three years, 2013-15, during which weather conditions shifted from dry to wet. Data were collected from 23-29 farms with more than 750 measurements. Most were on the Fort Lyon Canal.

The Lower Ark’s proposal to the state would provide more flexibility for frequency of irrigation as well, reflecting the number of days the ponds were filled.

“We will incorporate the data for the Fort Lyon Rule 10 plan this year,” said Bill Tyner, assistant division engineer. “We’re working on a provision to use the factors with owners not in the Fort Lyon plan.”

The state is working on the memorandum of understanding with the farmers and the Lower Ark district to make the numbers permanent.

There also will be periodic testing to verify the formula, and the tests will not be burdensome to farmers, Tyner added.

The farmers still must pay a fee to develop the annual plans, but will save money because of the need to purchase less replacement water.

“All of these efforts have been a huge benefit,” said Lynden Gill, chairman of the Lower Ark board. “When we started, there was a big wall in front of us. Now, things have come together.”

Straight line diagram of the Lower Arkansas Valley ditches via Headwaters
Straight line diagram of the Lower Arkansas Valley ditches via Headwaters

Robbing our groundwater savings accounts for today’s needs — The Mountain Town News

From The Mountain Town News (Allen Best):

Dick Wolfe, Colorado’s state water engineer, recently defined “sustainable groundwater supply” as one that is managed so that recharge matches withdrawals in a way to avoid long-term depletion of the aquifer.

By that definition, Colorado is not, for the most part, using its aquifers sustainably. Nor, for that matter, is most of the nation or world.

That much was made clear at a conference on Dec. 4 that was conducted by the American Ground Water Trust. Andrew Stone, the organization’s executive director, said 14 percent of all water used to irrigate crops in the United States comes from mining groundwater aquifers. This started slowly, but picked up as pumps and cheap energy became available around the end of World War II. The extraction by farmers and cities of water above the rate of recharge is now close to 400 cubic kilometers.

“We are robbing our savings account,” he said.

Driven by population growth and the uncertain effects of climate change, pressures on these subterranean savings accounts will only worsen, he said. This is not inevitable. He cited Los Angeles, which after World War II turned to groundwater exploitation to satisfy growth. “In the 1960s, it was pretty clear that the LA Basin was cruising for big trouble,” he said. But unsustainable exploitation has ended.

Problems of groundwater exploitation are common in many areas of the country, but solutions must be forged locally, “aquifer by aquifer, region by region,” said Stone.

Sobering statistics

The day was littered with fascinating statistics. Jeff Lukas, of the Western Water Assessment, explained that of the 95 million acre-feet that falls on Colorado, only 14 million acre-feet end up as runoff in our streams and rivers. The remainder, 80 million acre-feet, evaporates or gets drawn back into the atmospheric through transpiration. Together, the two are called evapotranspiration, or ET.

This rate of ET will almost certainly rise as the atmosphere warms. In the last 30 years, temperatures have ratcheted up 2 degrees Fahrenheit. Climate models forecast another increase of between 2.5 to 5 degrees by mid-century in Colorado. By mid-century, the hottest summers of the last 50 to 100 years will become the norm.

Too, everything from corn to urban lawns will need 5 to 30 percent more moisture during the longer, hotter summers—assuming precipitation does not increase.

How much precipitation will change as the result of elevated greenhouse gases in the atmosphere remains a mystery. Unlike temperatures, average precipitation in Colorado has not changed appreciably in the last three decades. Climate models have been clear about increasing temperatures, but precipitation remains a flip of the coin.

However, warming alone will drive changes, “pushing both the supply and demand in the wrong direction,” said Lukas. Increased evapotranspiration will reduce runoff and the amount of moisture available to percolate into soils and down into aquifers. Spring runoff has already accelerated and will come one to three weeks earlier.

Bottom line: Hotter temperatures will drive farmers to suck up more subterranean water. If anything, aquifers will recharge more slowly.

Wolfe, in his turn at the microphone, had even more statistics: Of Colorado’s 16 million acre-feet, 10 million acre-feet flow out of state, mostly as a result of compacts governing the Colorado and other rivers.

“That leaves us about 6 million acre-feet in Colorado to use,” he said. This surface water provides about 83 percent of water used in Colorado, and the other 17 percent comes from aquifers, which are tapped by 270,000 wells.

Of this groundwater, 85 percent goes to agriculture, for more than 2 million acres, but there’s also a strong urban component. One in five Coloradans get their water from wells. Most prominent are Denver’s southern suburbs in Douglas County.

Denver’s South Metro

South Metro has been a poster child for living in the moment. It’s affluent and rapidly growing. Served almost exclusively by wells, the residents of Castle Park, Parker and adjoining areas comprise about 6 percent of Colorado’s population but command 30 percent of income. Today’s population of 300,000 residents is projected to grow to 550,000 by mid-century.

Wells have been dropping rapidly, five feet in just one year in Dawson, one of the aquifers.

Eric Hecox, executive director of the South Metro Water Supply Authority, explained that it was always understood that wells would not last forever. The area had hoped to benefit from Denver’s Two Forks Dam, which was to have been filled primarily by expanded diversions from the Western Slope.

Two Forks was sunk by environmental concerns in the early 1990s. Inconveniently, Douglas County surged in population, routinely landing in the top 10 of the nation’s fastest-growing counties, a distinction that only lately has abated.

Other projects have also nudged the South Metro area off its exclusive dependence on groundwater, but even collectively they do not provide the answer. Hecox called for continued efforts to pinpoint needs while creating a new generation of partnerships and infrastructure.

Can South Metro’s needs for sustainable water supplies be answered by building a giant pipeline from Flaming Gorge Reservoir, on the Utah-Wyomng border? That idea was proposed in 2006 by entrepreneur Aaron Million, and then echoed by Frank Jaeger, the now-retired director of Parker Water and Sanitation District.

Hecox said the Bureau of Reclamation study about water availability from Flaming Gorge has not been completed. That study will provide the 14 members in Hecox’s South Metro coalition “base information on which to decide whether we want to pursue it any further,” he said.

Two key agriculture areas

Two agriculture areas in Colorado that rely upon aquifers are in arguably worse shape. The San Luis Valley has an area called the Closed Basin. With the arrival of electricity to farms in the 1950s, large-scale pumping began and, for a number of years, all went well, said Steve Vandiver, general manager of the Rio Grande Water Conservation District.

Despite earlier hints of problems, the magnitude of over-pumping started becoming apparent in 1998. One million acre-feet had been pumped from the aquifer above the amount of recharge. Figuring out what to do took time and negotiation. “There have been rocks thrown from every quarter,” he said.

The plan now in place has cut pumping by 30 percent during the last three years. The amount of irrigated acreage has declined from 175,00 to 150,000 acres. Water use on those remaining acres has been reduced in some cases by planting different, less water-intensive crops and also by using different irrigation methods.

Up to 300,000 cubic feet per second of water continues to be pumped on the fields in the Closed Basin on hot summer days.

And the Ogallala….

The Ogallala Aquifer is perhaps America’s best-known story of groundwater depletion. It extends over parts of eight states, from Texas to South Dakota, and the aquifer has declined at a shocking rate in several of those states, but more slowly or not at all in places, especially the Nebraska Sand Hills.

The Republican River Basin of northeastern Colorado is emblematic of many. Farmers working with local districts and the state government have been shifting the paradigm. Whether they’re shifting rapidly enough is an open question.

The river and its tributaries originate on the high plains, gaining no benefit from mountain snowpack. Yet this region had 480,000 irrigated acres in an area where annual precipitation is only 17 inches a year.

The key: mining the Ogallala. In the late 1970s, Colorado began taking action to slow the unsustainable over-pumping, but more radical measures were triggered by the need to comply with the interstate compact governing the river shared with Nebraska and Kansas. Colorado was forced to release more water downstream.

It did this partly by abandoning Bonny Reservoir, eliminating the evaporative losses. At greater expense, the district constructed an expensive pipeline and now pumps water—ironically from wells—to release into the Republican River at the state line. The total cost of the pipeline and the purchase of water rights was $48 million.

Much is being done to steer the Titanic away from the iceberg of exhausted aquifer water, but Deb Daniel, general manager of the Republican River Water Conservation District, suggested the magnitude of the challenge when she said: “Sustainable, that’s a scary word where I come from.”

(For a story I recently wrote about the Ogallala in Colorado, see the Headwaters Magazine website).

Wells along the South Platte

Unlike everything else said in the day, several speakers argued that not enough pumping has been occurring along the South Platte River. Their solution: more reservoirs and also more acreage returned to production.

Robert A. Longenbaugh, a consulting water engineer, pointed to 400,000 acre-feet average annually flowing into Nebraska above the compact requirement. “I call that a waste of water,” he said. At the same time, he and others pointed to reports of basements in Weld County getting flooded because of rising groundwater levels.

Even in the 1960s, a Colorado law was adopted that formally recognized that aquifers and surface streamflows comingled waters . In other words, if you have a well a quarter-mile from the South Platte River at Greeley and pump it, that might mean less water in the river as it flows toward Fort Morgan.

The drought of 2002 forced the issue, and in 2006 the state put well irrigators into the priority system. In 2012, a hot and dry year, many wells had to be shut down and corn and other corps left to dry up. Longenbaugh called for changes.

“Strict priority administration of ground and surface rights does not maximize the beneficial use,” he declared. Instead, he wants to se a “real-time management of the South Platte, to monitor surface and ground water and “make short-term decisions” looking out six months ahead while still maintaining the priority-appropriation doctrine that is the bedrock of Colorado water law.

A panel of state legislators later in the day acknowledged varying degrees of agreement with Longenbaugh’s statement. Sen. Mary Hodge, a Democrat from Brighton, described a pendulum that went from “too lax” to now one of being “too stringent.”

Sen. Vicki Marble, a Republican from Fort Collins, described the situation as deserving of an “emergency measure.” She later added: “We should let people self-regulate,” while suggesting that the wells should be allowed to pump. “It’s their right,” she said.

More groundwater coverage here.

Lake Pueblo State Park: Proposed new pumping rules to be discussed November 17 #ArkansasRiver

Arkansas River Basin -- Graphic via the Colorado Geological Survey
Arkansas River Basin — Graphic via the Colorado Geological Survey

From The Pueblo Chieftain (Chris Woodka):

Groundwater rules that could help certain farmers avoid some of the cost of water court applications are being considered for the Arkansas River basin.

“We’re not necessarily committed to this idea, but it may have benefits,” Water Division 2 Engineer Steve Witte told the Southeastern Colorado Water Conservancy District board Thursday. “The public needs to weigh in.”

The first chance to do that will be at a meeting at 1 p.m. Nov. 13 at the Lake Pueblo State Park visitors center auditorium.

The rules would apply to water replacement plans for post-1985 pumping, new uses for wells drilled prior to 1985 or new wells. They would provide an administrative alternative to water court, which can be too expensive for individual water users to navigate.

Witte reviewed the history of legal issues surrounding wells in the Arkansas Valley, including the 1972 attempt to reconcile surface and groundwater use, the Kansas v. Colorado case filed in 1985 that led to the 1996 well rules and the Simpson v. Bijou decision by the state Supreme Court in 2003 that took many well augmentation plans out of the hands of the state engineer.

“Decreed plans for augmentation costs have been so prohibitive in the South Platte that thousands of wells remain shut down to this day because of Simpson v. Bijou,” Witte said. There have also been instances in the Arkansas River basin, he said after the meeting.

On the same day that the Simpson v. Bijou ruling came, the state Legislature entered the Arkansas Valley well rules into law. In 2003, it also gave the state engineer’s office authority to approve five-year substitute water supply plans and to develop future rules.

Nearly 1,800 wells in the Arkansas Valley are covered by Rule 14 group augmentation plans under the 1996 rules, and those would stay in place even if new well rules are adopted.

The new rules could benefit a farmer who wants to use his own surface water rights to replace water pumped from wells, revegetation projects or even someone drilling a new well for a business, Witte said. At the same time, they would protect downstream water users and Colorado’s obligation under the Arkansas River Compact.

Witte acknowledged that there might an “augmentation gap” that makes finding sources of replacement water difficult, as discussed by the Arkansas Basin Roundtable recently. Permanently changing water uses still would require a trip to court.

But he said the purpose of the rules would be to give farmers a new tool to stay in business while complying with water law.

“We’re relying on data that were developed 30 years ago,” Witte said. “Life goes on and we need to think of ways to adjust and not be hampered by things already in place.”

More Arkansas River Basin coverage here.

Arkansas Basin Roundtable approves $175,000 for tailwater study

Flood irrigation in the Arkansas Valley via Greg Hobbs
Flood irrigation in the Arkansas Valley via Greg Hobbs

From The Pueblo Chieftain (Chris Woodka):

The state is being asked to help fund a study that looks at farmers’ contentions that estimates for return flows to the Arkansas River are inflated. A standard of 10 percent for tailwater — water that sheets off fields during irrigation before it can soak in — is used in mathematical models adopted during the 24-year Kansas v. Colorado U.S. Supreme Court case under the Arkansas River Compact. Those models also affect consumptive use rules that apply to surface water improvements such as sprinklers or drip irrigation.

The Arkansas Basin Roundtable last week forwarded a $175,000 grant request to the Colorado Water Conservation Board to determine if that number is too high.

“Farmers on the Fort Lyon did not believe 10 percent was really happening,” said Leah Martinsson, a lawyer working with the Lower Arkansas Valley Water Conservancy District, which is applying for the grant.

Straight line diagram of the Lower Arkansas Valley ditches via Headwaters
Straight line diagram of the Lower Arkansas Valley ditches via Headwaters

The ditch is more than 100 miles long and irrigates 94,000 acres and usually water short. That increases the likelihood that the estimate of tailwater runoff is too high, since much of the water never makes it back to the river, she explained. The higher the tailwater number, the greater the obligation from farmers to deliver water to the Arkansas River. So, reducing the figure in the group augmentation plans filed with the state would mean a reduction in the amount of replacement water.

While the concern of Fort Lyon farmers is the model used in the consumptive use rules, it also could affect the hydrologic-institution model that guides Colorado’s obligation from wells.

“If we are prepared with good technical data, we will go in and try to change the H-I model,” said Bill Tyner, assistant division engineer with the Division of Water Resources.

It would not be the first attempt to change the model. The state also is funding an ongoing lysimeter study at Rocky Ford to determine if evapotransporation rates in the Arkansas Valley are higher than assumed in the model.

Another study is looking at whether ponds that feed sprinklers leak more than the model assumes.

More Arkansas River Basin coverage here and here.

Lower Arkansas Valley Water Conservancy District board meeting recap

Orr Manufacturing Vertical Impact Sprinkler circa 1928 via the Irrigation Museum
Orr Manufacturing Vertical Impact Sprinkler circa 1928 via the Irrigation Museum

From The Pueblo Chieftain (Chris Woodka):

More than 28,000 acres of Arkansas Valley farm ground — roughly a tenth of all irrigated land — is being covered by group plans that guard against increased consumptive use from surface irrigation improvements.

The state pushed consumptive use rules for irrigation through Division 2 Water Court in 2010. The rules are meant to protect Colorado in its 1949 Arkansas River Compact with Kansas.

Rule 10 allows groups to file plans in order to save on legal, engineering and administrative costs.

The Lower Arkansas Valley Water Conservancy District is administering two Rule 10 plans this year.

One covers farms on the Fort Lyon, which represents 18,000 acres. About 12,000 of those acres are under sprinklers, while the remainder are flood irrigated.

The second plan covers 10,000 acres not on the Fort Lyon Canal, with two-thirds of that under sprinklers and 105 acres using drip irrigation.

“About two-thirds of the farm are in the Fort Lyon plan. The goal is eventually to have them in their own group plan that would be self-sustaining,” said the district’s engineer Jack Goble during a presentation at Wednesday’s board meeting.

This year’s Lower Ark plans cover 235 improvements on 92 farms that should require almost 1,900 acre-feet of replacement water. The amount owed is determined by a mathematical model devised by the Colorado Division of Water Resources that determines how much water would have been used before and after improvements.

“It’s a guess of what we’ll owe,” Goble said. “The model is almost like a parallel universe.”

The more water used in irrigation increases the amount owed to replace depletions in the river.

“The more water that comes through the ditch, the more is owed,” Goble said.

Goble walked the board through the complicated model, which takes irrigation flows, precipitation, seepage and runoff into account.

The Lower Ark district is in the second year of a study on pond leakage, which so far is showing that more water is escaping than accounted for in the state’s model. Data from the study in some cases has been applied to specific ponds.

More Ark Valley Consumptive Use Rules coverage here and here.