RIO GRANDE HEADWATERS — The Rio Grande begins its descent at Stony Pass in San Juan County and winds through Hinsdale and Mineral counties to towns downstream and the legally entitled states of New Mexico and Texas before reaching the Gulf of Mexico.
As former and current Colorado Attorney Generals Ken Salazar and Phil Weiser noted during the first Rio Grande State of the Basin Symposium in Alamosa on Saturday, Feb. 23, the story of the Rio Grande flows from the legal, economic and ecological tributaries governing its future. But at the headwaters of the story, the past is ancient.
The geologic events that shaped the uniquely fragile Rio Grande headwaters basin happened ages ago. The human migration trickling into the San Luis Valley followed later, but nonetheless in ancient times. Centuries would pass before water awareness compelled inhabitants to designate ditches and determine parameters for using the water. In 1852, the San Luis People’s Ditch in the Culebra Creek drainage became the first on record for the Upper Rio Grande, followed by the Guadalupe Main Ditch in 1855, Conejos River ditches in 1859 and the Silva Ditch in 1866.
Statewide, Colorado designated the Water Commissioner structure in 1879, and the system is still in place today. Seven districts for seven basins continue to track data as it flows. Serving the Rio Grande Basin in the Valley, Colorado Division of Water Resources Division 3 Engineer Craig Cotten opened the floodgates with information for symposium audience members at Richardson Hall on the Adams State University campus. Cotten said that 30 staff members tour the fields and rivers on a daily basis. They meter wells and, if necessary, notify owners to turn ditches on and off.
Salazar noted receiving this kind of bad news as a child growing up in the Valley. For four generations before him, the Salazars made a living raising alfalfa. But when interstate compact rules were enforced, the junior ditch rights could no longer sustain the family’s crops.
“We’ve been through tremendous pain and litigation for protecting this Valley,” Salazar said. “We’re not there yet. We still have huge challenges ahead of us, like threats to export water from the Valley and other kinds of threats.”
Salazar credited cooperation among Valley residents for addressing problems since the first legal interstate framework established in 1938, a theme reinforced throughout the symposium and demonstrated as limiting milestones passed. A 1972 decision included a moratorium on drilling new wells in most parts of the San Luis Valley. In 1981, the moratorium expanded to include the unconfined aquifer and the Closed Basin area.
With the rules in place, rights assigned and new restrictions added, the story should have ended around 1900. At that time, all the appropriations had owners. But compact enforcement beginning in the 1960s created new challenges, resulting in more legal changes during the 1970s. Slivers of ownership revealed through diligent inspection show a maze as complex as the boundaries beneath the surface of the Valley floor. Sandy layers mingle within vertical boundaries between surface water, ground water, an unconfined aquifer with sporadic evaporation zones and a confined aquifer locked deeper beneath a thick coal bed. Sequestered in the northern lip of the Valley, the appropriately named Closed Basin covers an additional 2,940 square miles.
The San Luis Valley currently averages seven inches of precipitation a year, and it doesn’t fall evenly throughout the basin. Beneath the surface, the confined and unconfined aquifers don’t flow evenly either. Precipitation counts throughout the Valley can be like temperature readings. When Alamosa records record lows, thermometers in Saguache County and other locations quietly show even lower numbers.
Historical lows are as legendary as snowpack highs, numbers seldom seen these days. After three years of recovery, the unconfined aquifer in Subdistrict 1 lost 230,323 acre feet in 2018, a disturbing low number that zeroed out the recovery. On the high end, two of the 10 largest wildfires in Colorado burned on the eastern and western edges of the Valley (West Fork Complex and Spring Fire). Another alarming trend, all 10 megafires have occurred since 2002.
Numbers matter then and now, particular considering benchmarks used for today’s agreements. Historical recordings came during a time when today’s numbers were unimaginable. The first compact signed in 1938, for example, set depletion-restoration levels according to data from 1929. Every dizzying chart displayed during the symposium in Alamosa showed ghastly declines. According to data from 2002 and 2018, it’s not 1929 anymore. Who could imagine harboring fond memories of the year the Great Depression began?
Looking ahead, the new weather data gathering facility in Alamosa will further refine analysis for managing the flow of water from the Upper Rio Grande.
Once the audience for the final session of the symposium settled into their seats in McDaniel Hall, the exercise had the trappings of a timeshare sales pitch. But since attendees voluntarily devoted an entire Saturday for the issue, the session made sense. Discussing in tiny groups before sharing with everyone, people recapped what happened, why it mattered and what to do about it. The shared comments reflected a history of commitment to solving problems, a history bolstered by kudos from Salazar and Weiser for already demonstrating that the San Luis Valley approach to water management is a step ahead of other regions suffering aridification around the world.