āBe careful of rattlesnakes,ā Brian Werner says as we walk near what will, a few years out, become the south end of Chimney Hollow Reservoir. I try to imagine what will happen to the snakesāand the bears and birds and burrowing animalsāwhen these 1,600 acres become a lakebed. Iād been conducting an animated interview with Werner for more than an hour as we toured the regionās waterworksāreservoirs, pipelines, diversion ditches, pumpsābut now, standing here, Iām speechless. Perhaps sensing my mood, Werner tries to be upbeat. He gestures to the west, where, as part of the reservoir land-acquisition deal, another 1,800 acres will be permanently protected. But itās hard to stand beneath those ponderosas and not feel a kind of heartbreak.
Werner works for Northern Water, a public utility that delivers water to parts of eight northeastern Colorado counties and about 880,000 people. In conjunction with the U.S. Bureau of Reclamation, Northern Water administers the Colorado-Big Thompson Project, a sprawling collection of reservoirs and pipes built to send Colorado River water from the western part of the state across the Rockies (through a tunnel beneath Rocky Mountain National Park) the more populousāand growingānortheastern towns. Wernerās job title is public information officer, but after 34 years with the utility, heās also its de facto historian, with an insiderās deep knowledge of the entire stateās water past and present, including the intricacies of water rights. (Western water law is an unfathomably complex beast predicated on a first-come-first-served system, which is why newer cities, late to the game, are struggling for rights to water that often flows right past them.)
Up and down Coloradoās Front Rangeāthe string of cities perched along the Rocky Mountainsā eastern flanksāitās a boom time. Fort Collins, the northernmost city, has doubled its population since the 1980s, with no sign of stopping. Farther to the east, in former rural communities like Frederick, Dacono, and Evans, pavement is spreading like weeds, subdivisions are sprouting in place of corn. The reservoir soon to drown the spectacular landscape under my feet that afternoon would deliver water to these bustling communities.
Nearby, another proposed reservoir would submerge a highway to store water from the Poudre River, which flows through downtown Fort Collins; this project will serve those same growing towns. āSome people think if we donāt build those projects, people just wonāt come,ā Werner says. āI wish that were the case. But itās not gonna happen. People are going to keep moving here, because itās a great place to live.ā
Across much of the West, the story is similar. As cities and states grapple with urban growth alongside the impacts of global warmingācrippling drought, a shifted timeline of snowmelt and stream flows, uncertainty about future water suppliesānothing is off the table when it comes to securing access to water. These days, the stories that make national news are more likely to be about old dams coming down than about new ones rising. Thatās partly because dams coming down are still a rarity. But across the West, the local news is far more likely to be about smaller dams going up. The era of water mega-projects may be behind us, but engineers are still transforming landscapes to deliver waterāan increasingly elusive and valuable commodity…
āThe Reclamation eraāāroughly the 1930s to the 1970sāāwas big monster projects, massive dams that totally reshaped the watershed, rivers, and ecology,ā says Reagan Waskom, director of the Colorado Water Institute at Colorado State University in Fort Collins. Todayās projects, Waskom says, are a series of āexpansions and enlargements,ā smaller-scale efforts meant to complement or shore up existing systems…
A subsidiary of Northern Water, called the Municipal Subdistrict, runs the Windy Gap project, which was built in the early 1980s to provide water for Boulder, Fort Collins, and four other Front Range cities. The system pulls water from the Colorado River and stores it in the Windy Gap reservoir on the west side of the Rockies then delivers it to Lake Granby, where it is pumped through the Big Thompson system to the eastern side. But in wet years, Lake Granby, the main reservoir for that Big Thompson system, is already fullāleaving no room to store the Windy Gap water. That means in dry years, when the customers really need it, the water isnāt there.
Chimney Hollow is the solution, a way to stabilize the Windy Gap water supply. Water managers call it āfirming.ā Imagine that you are technically entitled to ten units of water out of a reservoir that stores 100 units. But in a dry year, the reservoir might only contain 30 units, and there are other customers besides you. In such a system, you couldnāt really depend on the reservoir for your water. That worst-case scenario is what water people call āfirm yield.ā
On the Windy Gap system, the firm yield is currently zero. āIn the dry years, thereās no water available,ā explains Werner, āand in the wet years, thereās nowhere to put it. You canāt rely on a project with zero firm yield.ā Chimney Hollow, the utility contends, will give customersāthe city of Erie, sayā guaranteed annual delivery of their legally allotted water.
āEven with climate change, we know that there will be high flow years,ā Waskom says. āWhen those come along, youāve either got a place to store that water or you donāt.ā[…]
Thereās also the issue of whether there will continue to be enough water in the rivers to make these efforts worthwhile. āWhether you have a big reservoir or just a straw where youāre sucking water out of the river and sending it somewhere else, the question is, will the water be there?ā says Jeff Lukas, a researcher with the Western Water Assessment, a think tank based at the University of Colorado. āJust because youāve done the modeling and your scheme wouldāve worked under the hydrology of last 50 years doesnāt mean itāll work in the next 50 years.ā[…]
The new world is nothing if not complex. Itās a world of tradeoffs, a world without easy answers. Still, standing on the hillside at Chimney Hollow, Iām sure of one thing: I wish there was some way to spare this spectacular place.