From The Pueblo Chieftain (Chris Woodka):
Miles of irrigation ditches would be dug to create a carpet of fields on what once had been called The Great American Desert. There would not be enough water for all of them to operate as planned in the great vision of the time: a patchwork of family farms stretching to Kansas. There would be epic fights inside and outside of courtrooms to claim the water under Colorado’s constitutional provision that water first put to beneficial use has top priority. The rights to use the natural flows of the basin — other than spring runoff and floods — were pretty much spoken for by 1884.Water rights junior to that date are less often in priority, usually in times of high water. Ideas such as storage, importing water from the Colorado River and temporary sales of water have stretched the supply. There also would be a century-long tug-of-war between Kansas and Colorado over the amount of water that Colorado, the upstream state, was entitled to use…
As the region continued to grow, the pressure on its water resources would become ever greater and scarcity more evident. Several grand-scale projects — the Twin Lakes Tunnel, Homestake and the Fryingpan Arkansas Project — and many smaller transmountain diversions staved off the thirst by bringing new water into the basin.
But over time, even with the additional water, the cities and farms of the Arkansas River basin have had to stretch the supply. Incredibly, the booming city of Aurora in the South Platte basin, came hunting for water — and found it — in the Rocky Ford area in the 1980s, taking water from a basin that already had lived through a century of shortages.
More coverage from Chris Woodka writing for The Pueblo Chieftain. From the article:
Of the snow and rain that annually falls in the Arkansas River basin — 6.2 trillion gallons — less than 10 percent is used by man. “More than 90 percent is lost through evaporation or through transpiration,” [Pat Edelmann, who heads the Pueblo office of the U.S. Geological Survey] said…
Over the last 30 years, the need for good information about the river and its tributaries has increased. Cities and power companies have stepped up demand for water that once irrigated crops, and storage has shifted toward municipal needs. A rafting industry has been created on the Upper Arkansas River. Kansas sued Colorado over expanded use of water, prevailing in its U.S. Supreme Court claim that it was being shorted at the state line. “The USGS tries to provide the facts, as well as useful interpretation so the best decisions can be made,” Edelmann said.
Some of its current efforts include a basinwide water study for a water resources group formed under the 2003 Southeastern Colorado Water Conservancy District agreement with Aurora, a Fountain Creek flood control study and a better understanding of how snow melt affects streamflow in the Upper Arkansas. The agency also is involved in the Colorado Water Conservation Board’s decision-support system that will attempt to link numerous other investigations in an effort to describe what’s about to happen when you move the water from Point A to Point B…
Reservoirs constructed over the last 100 years capture that flow for use later in the growing season. The great majority of storage at high-mountain reservoirs, where it is most valuable, has been taken over by cities. At Lake Pueblo, the switching yard for water as it travels in the basin, cities are increasingly using the space they are entitled to each year.
Imports from the Western Slope add the greatest amount of water to the supply, increasing flows in the Arkansas River at Canon City by 25 percent, according to a study by the Bureau of Land Management in 2000…
Since 1990, there has been a voluntary agreement among water suppliers to keep flows higher during rafting season and optimal for fish at other times of year in the Upper Arkansas River basin.
The agreement is made possible by controlling when releases are made from Twin Lakes to Lake Pueblo each year in order to make space for the next year’s imports.
More coverage from Chris Woodka writing for The Pueblo Chieftain. From the article:
In a typical year, the flows of the Arkansas River are enhanced roughly 25 percent by water brought in from the Colorado River basin. The great bulk of the water is brought over by cities to supplement supplies they own within the basin.
Colorado Springs brings water from the Blue River in Summit County and as partners with Aurora in the Homestake Project in Eagle County. El Paso County’s largest city also is the largest shareholder in the Twin Lakes Reservoir and Ditch Company and receives 25 percent of the water brought over by the Fryingpan-Arkansas Project. About 80 percent of its supply is imported…
Pueblo gets about half of its total supply from transmountain diversions. Over the years, the water board has formed working relationships with Colorado Springs, the Southeastern Colorado Water Conservancy District, Aurora and, perhaps most importantly, the Western Slope. “Pitkin County and Aspen are more aware, so taking more water out of the Roaring Fork watershed is difficult,” [Bud O’Hara water resources chief for the Pueblo Board of Water Works], said. “I think we need more of a cooperative effort with the Western Slope. Storage will be a big factor, but it gets back to cooperation.”
The earliest water projects were largely a proposition to take water from one side of the mountains to the other. Over time, compensatory storage in the basins where water was delivered from became the typical mitigation. Today, there are social and economic issues that are rooted in the attitude that Colorado River users need their own supplies to meet future needs.
More Arkansas River basin coverage here.