San Luis Valley: New groundwater pumping rules

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Over 400 groundwater irrigators in the South Platte River Basin have been shutdown in recent years following shutdowns and curtailments in the Arkansas River Basin after Kansas sued Colorado. The state is trying to convince Nebraska that a proposed pipeline releasing into the Republican River at the border will meet Colorado’s requirements under the Republican River Compact. The nexus between groundwater and surface water is becoming well known if not entirely understood.

In an attempt to avoid heavy-handed top-down regulation of groundwater pumping in the San Luis Valley, State Engineer Dick Wolfe, has formed a committee to come up with inclusive rules for pumping that are acceptable to everyone in the valley. The new rules — it is hoped — will satisfy senior surface rights holders, compensate them for past injury, allow most groundwater irrigators to stay in business and keep Colorado on the positive side of the Rio Grande Compact ledger. The state engineer’s office unveiled the first draft of the new rules this week. Here’s a report from Matt Hildner writing for the Pueblo Chieftain. From the article:

“You’ll see throughout this document there’s a number of places where we’ve put question marks,” Wolfe said. “We thought we need to address those but we weren’t quite sure how we should actually articulate that in these rules.” Wolfe expects a final draft of the rules to be submitted for water court approval by the end of the year, which would most likely come after the court has completed its review of a voluntary plan to limit groundwater pumping in the north-central part of the valley. Should the court approve the plan for Subdistrict No. 1, the engineer’s rules will include a way to accommodate operation of the subdistrict. Subdistrict membership would allow for pumping under the rules as would a court-decreed plan for augmentation.

But the framework regarding the timing of compliance with the rules included a host of questions: How long after approval of the rules will curtailment take effect? What if the court were to remand a subdistrict plan? The framework also raised questions about whether some geographic areas should be phased in, citing, for example, how little information the state had on the aquifer beneath southern Costilla County. “I think we all recognize we don’t want to inadvertently take too much of an extreme one way or another of either not handling them or restricting them too much when we don’t know enough about them,” Wolfe said.

A key component of both the rules and the operation of subdistricts will be the state’s Rio Grande Decision Support System, a computer model planners will use to predict when and where future groundwater use might harm senior surface water users or compact obligations. Kelly Sowards, one of the objectors to the subdistrict plan now under review by the court, raised the question of how the computer model’s results would be released in relation to the start of irrigation season. “It’s important for us to know quickly,” he said. Tim Buchanan, an attorney who represents Sowards and other objectors in the subdistrict trial, urged the engineer to write a procedure into the rules on when modeling would occur and how the public would be notified.

“We know a lot today compared to what we knew 30 years ago,” he said. Wolfe’s office hopes to gather all of the committee’s comments on the framework by April 24. The advisory committee will meet again May 13.

More coverage from Ruth Heide writing for the Valley Courier:

Wolfe hopes to get to a final draft by the end of the year and told the advisory committee that by working through questions and objections upfront he hoped to avoid objections to the final rules when they are submitted to the water judge later this year. “I come today with not being biased by the past,” Wolfe said. He was not involved in attempts years ago to develop groundwater rules, he said, and believed the state and water users have more information now than was available then. He stressed it was important to him that these rules be developed with input from those who would be affected by them. “Progress is going to be slow,” he said. The complex issues involved in this basin will take several months to work through, he said. “I know this process will be successful,” he added…

He asked the numerous members of the advisory committee to begin sending comments to the state regarding the initial draft in the next couple of weeks so the next draft version may be sent out to the committee before its next meeting in Alamosa on Wednesday, May 13. The committee will meet from 10 a.m. to 3 p.m. with educational items presented in the morning and the afternoon focusing on the rules themselves…

Wolfe reminded those present that all well owners would have to comply with the state’s rules governing groundwater withdrawal in Division 3 (the Valley) unless they are exempt. Exempt wells might be domestic wells, for example, or wells already under an augmentation plan, Wolfe explained. Otherwise, well owners will have to obtain an augmentation plan or substitute water supply plan, be part of a water management sub-district or face curtailed pumping…

The San Luis Valley has about 3,000 wells that would potentially fall under these rules…

The rough draft Wolfe presented this week is somewhat of an outline of the various topics that must be addressed in the rules. The draft includes 14 sections from the title (“Rules Governing the Withdrawal of Ground Water in Water Division No. 3”) and authority (state statutes) to the effective date (60 days after publication, if there are no objections.) In between are sections regarding the purpose of the rules, definitions, requirements, standards for review of applications (namely the Rio Grande Decision Support System groundwater model), compliance plans and timing for compliance, geographic scope (nearly the entire Valley) and irrigation season. The determination on when the irrigation season will begin and end according to the rules is one of the items Wolfe said would require much discussion and probably the establishment of a sub-committee. In addition to the sections Wolfe included in his first draft, he questioned whether the rules should also include sections for variances and appeals. Wolfe said the section in the rules defining their scope and purpose was one of the most important. That was the portion most fleshed out in his initial draft. He said he incorporated comments from the advisory group’s first meeting.

Objectives he included in the initial draft included: optimally use water “consistent with preservation of the priority system of water rights and protection of Colorado’s ability to meet its interstate compact obligations;” regulate aquifers to maintain a sustainable water supply; recognize the aquifers as underground storage reservoirs; maintaining artesian water pressures consistent with those experienced in the years 1978-2000; and recognize the obligations to replace injurious stream depletions and fulfill obligations under the Rio Grande Compact.

Here’s a look at the technical challenges for modeling the hydrogeology of the valley, from Ruth Heide writing for the Valley Courier:

Before presenting the first draft of the proposed well regulations this week, the state engineer’s office provided background on subjects such as the Valley’s hydrogeology and the Rio Grande Decision Support System. All of these subjects play a part in the well regulations. Geologist Eric Harmon described the Valley’s hydrogeology as a 100×40-mile three-dimensional, multi-layered jigsaw puzzle with no picture on the puzzle box to guide those trying to put it together. The fact that changing one puzzle piece can affect many more or even the entire picture is one of the challenges of those trying to put together well regulations that are equitable. Folks have been studying the Valley’s hydrogeology since the 1890’s, and although the tools to study it are more advanced now than then, the experts still do not have it all figured out, Harmon explained. In the last decade the state spent about $8 million developing the Rio Grande Decision Support System (RGDSS), a model of the Valley’s hydrology…

Harmon said the Valley consists of very different and complex geological regions that make efforts to define it difficult. He said underneath the Valley’s seemingly uneventful surface lie faults, inter-bedded layers of clay and sand, gravel, basalt, rocks and water flowing among all of that. Harmon said the RGDSS computer model has five layers and 51,000 cells, but “even that model cannot show all the geological complexities of the Valley.” He said in certain areas the model still requires refinements to reflect the realities of the Valley’s hydrology. He added that in some areas the model works very well and other areas it does not accurately reflect what is happening in the real world.

More Coyote Gulch coverage here and here.

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