Two large water projects that state officials are thinking about building come with hefty price tags — that much is certain. What's not so cut and dried is what the environmental costs would be.

They are at opposite ends of Utah. In the north, the Bear River Development Project would cost $260 million, while in the south, the Lake Powell-St. George Pipeline Project is pegged at about $370 million.

The total, $630 million in today's dollars, would rise dramatically if paid for later. According to the Washington County Water Conservancy District, the pipeline and Fort Pearce Reservoir alone would rocket to more than $593 million in 2018 dollars.

Gov. Olene Walker recently established the Water Delivery Financing Task Force to consider how to pay for the projects. Meanwhile, other questions have surfaced about less quantifiable costs.

• Bear River Project

The U.S. Bureau of Reclamation began studying the Bear for new reservoirs in the 1950s, according to an August 2002 report by the Division of Water Resources. In 1991, the Legislature approved an act to develop the water of the Bear River and its tributaries.

As later tweaked, the physical aspects of the project would involve connecting the Bear River with Willard Bay via pipeline or canal, constructing conveyance and treatment facilities to take water from Willard Bay to the Wasatch Front, and building a dam in the Bear River Basin.

The dam originally was to be near Honeyville, Box Elder County, but environmental concerns caused a change in the plan. Now the reservoir site is Washakie, located east of Washakie, Box Elder County, about 10 miles north of Tremonton.

The reservoir would hold 160,000 acre-feet and cover 4,906 acres. Berms would be built on three sides, with I-15 running along a crest on the fourth (eastern) side.

The dam would not be across the Bear River. Instead, water would be diverted from the Bear below Cutler Reservoir to this site, conveyed about 13 miles. Meanwhile, the Malad River would be rerouted away from the reservoir because the Malad is too salty. A Utah Power electrical line would be moved from the site, which is mostly farmland, and some homes would be removed.

Even with the siting change, said Merritt Frey, executive director of the Utah Rivers Council, the project definitely will cause environmental impacts on the Bear River and downstream areas.

"We're talking about diverting a significant amount of the flow of the river," she said. She believes riparian habitat would be affected.

If the river level drops and the water table goes down, that could affect plants and animals, Frey said.