In coming weeks, as long as the rain slows, an epic construction project will begin taking shape about 90 miles northeast of Dallas.

More than 300 acres of trees will be cleared, and crews will spend the next three summers digging out dense clay for what will become Texas' first new reservoir in 30 years.

Construction of an earthen dam and concrete spillway will be the most visible piece of the $1.2 billion Lower Bois d'Arc Creek Reservoir, which was dreamed up in the early 1980s and put into motion last month when the North Texas Municipal Water District won federal approval to begin.

But workers will also relocate a farm-to-market road, replace eight county road bridges, build a bridge across the middle of the reservoir, create new wildlife habitat, relocate power lines and fiber optic cables, and construct a new water treatment plant and 60 miles of water pipeline.

All of that is badly needed to quench the thirst of fast-growing neighborhoods and corporate campuses in Collin County and surrounding areas, water district officials said. The district provides water to nearly 1.7 million people in about 75 cities and communities in a 10-county region.

"There were a lot of high-fives in the office," Mike Rickman, a North Texas Municipal Water District deputy director, said about receiving the lake's federal permit after 15 years. "We pushed as hard as we could push."

Where North Texas water comes from

Current water sources for North Texas Municipal Water District

How the district is adding to its capacity by 2030

The new 16,641-acre lake, which could start providing water by 2022 and eventually pump more than 100 million gallons each day, is just one piece of a complex, multibillion-dollar strategy to ensure taps don't go dry.

Failure to keep pace with demand could lead to water shortages and cost the region as much as $34.6 billion in lost income by 2070 and a loss of 373,000 jobs, according to a Texas Water Development Board report. That was calculated before the Army Corps of Engineers signed off on Lower Bois d'Arc Creek.

Looking as far out as 2070, the region's water providers are counting on conservation, water reuse, new lakes and even out-of-state purchases to meet extraordinary demand from North Texas' burgeoning population, which is expected to nearly double over that time frame.

A McKinney water tower looms behind new homes on Leadville Way in fast-growing McKinney. The city's population now stands at nearly 180,000, a nearly 7 percent increase from last year and a 365 percent increase from two decades ago. (David Woo / Staff Photographer)

Between now and then, this 16-county planning region is projected to account for 38 percent of the state's new water demand. All total, the projects could cost $23.6 billion.

The new reservoir and plans to buy Trinity River water from south of Dallas are expected to keep the regional water district afloat until at least 2040. That projection makes assumptions about supply and demand during drought years.

In 2011, Texas experienced its driest year on record as part of one of the state's worst droughts. That persuaded utilities to order permanent outdoor watering restrictions. Generally, North Texas homeowners may water their lawns only twice a week during the growing season and only between 6 p.m. and 10 a.m.

Sprinklers along Sagewood Court in Plano, one of the cities in the North Texas Municipal Water District. (Andy Jacobsohn / Staff Photographer)

All large North Texas water suppliers, which include Dallas Water Utilities and the Tarrant Regional Water District, have plans that would meet water needs through 2070.

Not all parts of Texas are able to hit their goals. Matt Nelson, assistant deputy executive administrator for the state's water board, said some areas of the Panhandle don't have enough options. They can't ensure a full water supply during droughts.

Local water suppliers acknowledge that some of these plans, including buying water from Oklahoma and increasing the water supply from Wright Patman Lake near Texarkana, have hurdles that could derail them. Obstacles include local hostility and even government opposition.

While taken for granted by many, except during droughts, water continues to be a major concern for businesses. The Texas Association of Manufacturers included water conservation and supply in its February list of top 10 policy priorities.

"Our members routinely remind us that water is one of their biggest economic development concerns," said Tony Bennett, the association's president and CEO. "Just like they look very closely at the affordability and reliability of electricity ... water is now equal, if not even in some cases, more emphasized."

This is part of the North Texas Municipal Water District Water Treatment Plant in Wylie. The North Texas Municipal Water District uses a 'take or pay' system that essentially charges a city for the greatest amount of water it has used in the past. (File Photo / Staff)

Collin County is a focal point for growth thanks in part to the booming areas in West Plano, Frisco and McKinney. In the next 50 years, water demand there is expected to grow by 168 million gallons a day, or 84 percent. That's about the amount it would take to fill 255 Olympic-sized swimming pools.

Dallas and Denton counties are expected to need an even greater increase, 182 million and 184 million gallons of water a day, respectively. Those numbers already take into account existing lawn watering restrictions as well as savings expected from new low-flow plumbing.

Every five years, the state's Water Development Board works with regions to update 50-year plans of strategies and projects to meet water needs. Dallas-Fort Worth is part of a region that stretches from the Oklahoma border to Freestone County, south of Corsicana.

For North Texas planners, a major part of their work is securing new water sources, such as rivers and lakes, and then building pipelines to move that water here. But water suppliers are also leaning heavily on other approaches.

Conservation and reuse are expected to make up 32 percent of Dallas' water supply by 2070. For the North Texas Municipal Water District, that number is nearly 21 percent.

The state plan also anticipates that average usage would drop from 200 gallons per person per day to 165 gallons. That would offset only a small amount of the expected growth.

Where Dallas gets its water

Current water sources

How Dallas is adding to its capacity by 2030

Some water experts insist more must be done to encourage conservation and reuse. A new report from the Cynthia & George Mitchell Foundation urged water planners to consider drinking water, wastewater, storm water and gray water as a "single resource, a resource that must be managed holistically, viably and sustainably."

"The days of feeding vast Texas lawns with water so pure a newborn baby could drink it should cease immediately," the report said. "The practice of funneling stormwater into concrete culverts should stop as soon as possible."

Rachel Cardone, co-author of the Mitchell report and founder of RedThread Advisors, cautioned that there are no "silver bullets."

"This is an integrated approach that requires lots of different pieces of the puzzle to work together," she said.

What the report encourages is more regional collaboration, inviting outside experts and university researchers to vet plans and putting greater emphasis on living within a region's "water budget."

Janice Bezanson, executive director of the Texas Conservation Alliance, praised North Texas water planners for their work on some types of water recycling. Most commonly, treated wastewater is returned to other bodies of water and then captured again for treatment into drinking water.

That "indirect reuse" is expected to make up less than 4 percent of Texas water supplies in 2020, according to the state's water plan. But the North Texas region accounts for about 41 percent of the state's total.

North Texas Municipal Water District owns 2,000 acres of wetlands south of Dallas that's used to filter river water before it goes into its water system. The Tarrant Regional Water District also operates a 1,700-acre wetlands project that it says was the first of its kind in the nation.

Still, Bezanson said utilities should look to Wichita Falls and Big Spring for even more creative solutions.

In response to the last drought, both cities started water recycling programs similar to what's used in arid countries from Israel to Namibia.

The utilities take treated wastewater and run it immediately through a new water treatment plant featuring the same types of technology used to create bottled water.

Bezanson's nonprofit hired consulting firm Kleinfelder to estimate the cost of this strategy, known as direct reuse. Based on those numbers, the Texas Conservation Alliance concluded that approach would cost less than half the price of building Marvin Nichols Reservoir in northeast Texas and pumping that water to the Dallas area.

That 72,000-acre lake is projected to cost $4.3 billion and supply water to several major utilities.

The state's water plan provides conflicting estimates. Its projected price for direct reuse for drinking water is nearly double the cost of a new reservoir for the North Texas region.

Bezanson argued that the state figures are inflated, don't include the cost of treatment into drinking water and don't consider that the Marvin Nichols cost could be higher than the average.

Another tangible benefit of direct reuse is that it's scalable, Bezanson said. A utility could easily expand a treatment plant when needed, while a multibillion-dollar lake must be built long before its full capacity is needed.

There is some direct reuse in North Texas, but it's generally for irrigation rather than drinking water.

For Dallas Water Utilities, which also supplies about two dozen other cities and communities, nearly two-thirds of its strategy is reuse and tapping into existing water supplies.

In the short term, Dallas expects to get as much as 31 million gallons a day by swapping access to wastewater sources with the North Texas Municipal Water District. The recycled water can be reused to boost the supplies of both utilities.

The city is also collaborating with the Tarrant Regional Water District on a 150-mile pipeline connecting to Lake Palestine, where Dallas already has a contract for water. Dallas is paying for $1 billion of the project's $2.4 billion cost.

Other supplies could come from the Neches River and the proposed Lake Columbia, which isn't expected to be built until about 2070.

Projected water demand by county

Growth from 2020 to 2070, in millions of gallons per day

For the North Texas Municipal Water District, the immediate concern is construction of its new reservoir. Without new water sources, the district was staring at a potential 93 million-gallon-a day shortfall by 2030 if there were drought conditions.

Clearing the path to water intakes at Lavon Lake and Jim Chapman Lake would add 10 million gallons a day to the district's capacity.

The water district also plans to buy 50 million gallons of water a day from a section of the Trinity River between Kaufman and Ennis. That would flow through the district-owned wetlands to partially filter the water and then back into the larger system for water treatment.

By the 2040s, the district plans to start pumping an additional 35 million gallons daily from Lake Texoma. The North Texas Municipal Water District already owns the water rights but is limited by the saltiness of Texoma's water. It has to either be desalinated or diluted with another lake's water.

The district is already diluting as much Texoma water as it can in Lavon. Officials would need to wait until the completion of Lower Bois d'Arc Creek and then mix Texoma water with water from the new lake.

Parts of the New Jerusalem Baptist Church have been dismantled near Honey Grove in anticipation of its being flooded for the new Lower Bois d'Arc Creek Reservoir. (Tom Fox / Staff Photographer)

Other alternative plans are decades away and uncertain. The district could use water from the planned 72,000-acre Marvin Nichols Reservoir, but that has opposition from East Texas property owners, companies, environmentalists and politicians. There was a failed effort in the 2015 state legislative session to require the proposed lake to seek approval from an East Texas water board.

District officials are also hoping to buy water from Oklahoma, even though the export of water has been banned by state officials.

Plans to use Toledo Bend Reservoir, which straddles the Texas-Louisiana border, would be pricey since water would need to be pumped uphill and over a long distance.

Rickman of the North Texas Municipal Water District said long-term planning is valuable. But there are limitations, particularly when looking several decades ahead.

To secure new reservoir permits, utilities must wait until the need is imminent. However, Lower Bois d'Arc Creek showed that it's difficult to estimate that lead time.

"You can't invest a lot of money in something that's 50 years out," Rickman said. "Both in the state and the federal permits, you have to show purpose and need. ...We can't get way out ahead of the timeline."