Utah’s Bear River is an odd creature. Its headwaters and its mouth are only 90 miles (145km) apart. But the river takes its time spanning those points, flowing 500 miles over a tortuous path.

It begins high in Utah’s Uinta Mountains, then spills north into Wyoming and Idaho, looping around the Wasatch Mountains. Near the town of Soda Springs, Idaho, the river makes a hard left turn and then flows south, down the other side of the Wasatch and back into Utah, where it dumps into the Great Salt Lake.

The Bear River is Great Salt Lake’s largest tributary, contributing about 60 percent of the lake’s freshwater flow. It is also the largest river in the Western Hemisphere that does not reach an ocean.

Near the town of Brigham City, the river forms an inland estuary where it meets Great Salt Lake, a place of meandering channels, tall grasses and salty water that is one of the world’s most unique wetland habitats.

So it is no trivial matter that the state of Utah wants to spend $1.5 billion to build as many as seven new dams on the Bear River, along with a 50-mile pipeline linking them to urban water treatment facilities.

The Bear River Development Project is one of the largest water developments currently proposed in the United States, and is emblematic of the constant battle to serve a persistent thirst in the West. While many other growing urban areas plan to meet their water needs through strict conservation and water-recycling projects, Utah is taking an old-school approach.

State officials say the project is necessary to keep up with Utah’s rapidly growing population, which is expected to double to 6 million people by 2050. Most of these new residents will make a home in the Salt Lake City metro region, the intended service area for the new Bear River dams.

“It’s hard, because we do want to be good stewards of the environment,” said Marisa Egbert, manager of the Bear River Development Project at the Utah Division of Water Resources. “Yet at the same time, where do we get water for a doubling of the population? We have a lot of kids here in Utah. It’s a fabulous state to live in, so nobody wants to leave. That makes it even harder.”

The project calls for diverting as much as 220,000 acre-feet (271.3 million cubic meters) of water from the Bear River annually, enough to serve a half-million households. Among other potential consequences, this could drop Great Salt Lake’s water elevation as much as 4 feet (1.2m), potentially jeopardizing wildlife habitat and the lucrative mineral-development enterprises ringing the lake.

Zachary Frankel, executive director of the Utah Rivers Council, said diversions on that scale could dry up a half-million acres of Great Salt Lake wetlands.

“It’s a massive, massive project that would impact one of the most important ecosystems in the Western Hemisphere,” Frankel said. “This river that nobody has ever heard of is critical to the existence of somewhere between 8 and 10 million migratory birds, many of which gather in larger numbers at Great Salt Lake than anywhere else on the entire planet.”

The lake is also a vital source of minerals for various farming and industrial applications. The minerals are extracted from lake waters that are as much as 10 times saltier than the ocean.

For example, Great Salt Lake is the only source of potassium and magnesium in North America. The potassium is used in fertilizers, while magnesium is used in a variety of commercial products, from soda cans to automobile parts. The lake’s billion-dollar mineral industry supports about 7,000 jobs in the region.

Existing diversion of freshwater inflows – for farming and urban uses – have dropped the lake 11 feet, cutting its footprint roughly in half compared to pre-development conditions. Combined with the effects of an ongoing drought in the region, the lake is expected to shrink below a historic low set in 1963. Mineral producers were recently forced to spend millions of dollars relocating saltwater intakes due to this shrinkage of the lake.

The Bear River Development Project could reduce freshwater inflows to Great Salt Lake by an estimated 20 percent. As a result, it is one of the rare water projects that is opposed by both environmental and industry groups.

“It kind of bothers me that they are so intent on taking this water,” said Dan Tuttle, government affairs manager at U.S. Magnesium, the only magnesium producer in North America. “We’re looking at the same situation as Mono Lake and the Owens Valley. Once it’s gone, it’s gone.”

The Utah Legislature approved the Bear River Development Project in 1991. The state intends to pay for the project. It would be then be reimbursed by residential and commercial water users in five counties along the Wasatch Front, Utah’s most urbanized region.

Earlier this year, the Legislature approved a measure that diverts sales tax funds to pay for water projects, including the Bear River development.

Egbert said the project has been delayed several times since 1991 because Utah residents have been so good at conserving water in the interim. Gov. Gary Herbert is urging residents to cut their water consumption 25 percent by 2025.

“My understanding is, we’re getting really close and we should probably hit that goal even before 2025, which would be fantastic,” Egbert said. But she said it is unlikely Utah will be able to conserve its way out of its growing water demand, which is mostly caused by internal population growth, not new residents arriving from outside the state.

Frankel disagrees, noting Utah residents are among the heaviest water users in America.

A recent study by the U.S. Geological Survey found that Utahns consume 167 gallons of water per person each day, one gallon behind Idaho residents, the thirstiest Americans. The same study showed Californians consume 108 gallons per day.

One reason for this is Utah’s unusual method of billing for water. Residents pay for a portion of their water via property taxes. As a result, monthly water bills don’t provide an accurate pricing incentive to encourage conservation.

And those monthly water rates are exceedingly low in some cases, according to Frankel. In West Jordan, Utah – one of the cities to be served by the Bear River project – residential customers pay only $1 per thousand gallons of water. In comparison, Seattle residents pay more than $15 for the same volume, and Denver residents pay $5.

Cheap water may be partly why Facebook wants to build a massive new data storage center in West Jordan. It would require an estimated 5.3 million gallons of water daily for cooling purposes. That’s enough to serve 25,000 people. It would reportedly be one of the world’s largest data centers, with an energy demand of 180 megawatts. The city of West Jordan is offering $240 million in tax breaks to lure the project.

Frankel said basic water conservation programs and appropriate water pricing offer cheap alternatives to building new dams.

“If you walk across the Salt Lake Valley on a summer day, you will see gutters full of water,” Frankel said. “You will see people watering concrete because water is so cheap. And there are no repercussions for that. There are no water cops, there’s no water education, nothing like that.”

Utah’s Legislative Auditor General recently criticized the Division of Water Resources for exaggerating future water needs. When agricultural land is developed, water once used for crops is converted to urban purposes. A realistic look at those conversions, the auditor found, yields 50 percent more water for urban growth than the state claimed.

The state initially analyzed some four dozen potential dam sites, including some on the Bear River and some off-stream locations. That list was recently narrowed to seven locations for further study. One is actually inside the boundaries of the Bear River Migratory Bird Refuge, a federal wildlife refuge within the delta where the river meets Great Salt Lake.

Egbert said the proposed dam locations would likely be narrowed further, possibly to as few as three sites. She could not say what mitigations might be adopted for the river environment, migratory birds or Great Salt Lake itself. The project remains in early stages, with a full environmental impact study still to be done at some future date.

“How can this project bring a positive to all those that see it as just one big negative?” Egbert asked. “We think there might be some opportunity there, but nothing’s set in stone.”