Booming Front Range cities take first steps to build $500 million dam, reservoir near Holy Cross Wilderness — The Denver Post

Here’s an in-depth report from (Bruce Finley) writing in The Denver Post. Click through and read the whole article. Here’s an excerpt:

A hundred miles from Colorado’s Front Range house-building boom, field scientist Delia Malone dug her fingers into spongy high-mountain wetlands at the edge of the Holy Cross Wilderness.

She found, about 15 inches underground, partially decayed roots, twigs and the cold moisture of a fen. These structures form over thousands of years and store water that seeps down from melting snow.

Malone has been digging about 20 holes a day, surveying fens for the U.S. Forest Service, to better understand nature’s water-storage systems — which sustain vegetation and stream flows that 40 million people across the Colorado River Basin rely on in the face of increasing aridity.

Aurora and Colorado Springs are planning to flood these wetland fens and replace natural storage with a man-made system: a $500 million dam and a reservoir that may require changing wilderness boundaries.

The cities each own rights to 10,000 acre-feet a year of the water that flows out of the wilderness and would pump what the reservoir traps, minus evaporation, through tunnels under mountains to other reservoirs and, finally, to pipes that deliver steady flows from urban faucets, toilets, showers and sprinkler systems…

Fens play a key role ensuring that streams and rivers still flow after winter snow melts. And as climate warming leads to earlier melting and depletes surface water in the Colorado River, natural wetlands increasingly are seen as essential to help life hang on. The benefits stood out this summer as the West endured record heat, wildfires and drought…

Yet Front Range developers’ desire for more water is intensifying. Across the mountains at construction sites on high dusty plains, roads and power lines have been installed, heavy dirt-movers beep and carpenters thwack atop roofs.

Local governments already have approved permits allowing house-building at a pace that in some areas is projected to nearly double water consumption.

Colorado Springs officials issued 3,982 permits for new single family homes last year, 18% higher than the average over the previous five years, according to data provided to The Denver Post. They estimated the current population around 476,000 will reach 723,000 “at build-out” around 2070. This requires 136,000 to 159,000 acre-feet of water a year, city projections show, up from 70,766 acre-feet in 2019.

Aurora officials estimated their population of 380,000 will reach 573,986 by 2050. They’ve approved entire new communities, such as the 620-acre Painted Prairie with more than 3,100 housing units in the “aerotropolis” that Denver leaders have promoted near Denver International Airport, and projected current water consumption of 49,811 acre-feet a year will increase to 85,000 acre-feet and even as much as 130,158 acre-feet in a high-growth, rapid-warming scenario…

To make a new dam and reservoir more palatable, the cities are exploring unprecedented “mitigation” of digging up and physically removing the underground fens, then hauling them and transplanting them elsewhere to restore damaged wetlands. An experiment on a ranch south of Leadville, officials said, is proving that this could help offset losses of Homestake Creek wetlands.

This would challenge a federal policy laid out in 1999 at Interior Department regional headquarters in Denver that classifies fens as “irreplaceable.” The policy says “onsite or in-kind replacement of peat wetlands is not thought possible” and that “concentrated efforts will be made to encourage relocation of proposed reservoirs… that might impact fens, when practicable.”

Covered by grasses and shrubs, water-laden fens blanket the Homestake Valley — wetlands filled with porous peat soils that receive minerals and nutrients in groundwater. Moving such wetlands, if attempted, would require massive hauling of soil blocks combined with the delicate precision of an organ transplant to retain ecological functioning…

Some environmental groups are preparing for legal combat should the cities seek required state, county and federal permits. Others haven’t weighed in. Conservation Colorado leaders declined to comment on this water push.

Transplanting fens as mitigation to try to restore wetlands elsewhere “for our convenience” is impossible, WildEarth Guardians attorney Jen Pelz said. “Fens and other sensitive high-elevation wetlands are quite beautiful and mysterious, more art than science, not something we can re-engineer.”

Dams and diversions proposed in recent years around the West “are just as destructive as those built a century ago, and building dams today is actually more irresponsible because we know that dams disconnect aquatic and riparian habitat, cause species extinction, disrupt ecosystem function, dry rivers and harm native cultures and communities,” she said.

“We need to start removing dams, not building more. This project is one of many where water managers are looking to cash in on their undeveloped rights or entitlements at the expense of people and the environment. … It’s time to draw a line in the sand.”

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