THE WATER IS HIGH: City water storage system awash in runoff, complexity

AURORA | This year has been unusual for Aurora and the state as a whole — it’s one where the city doesn’t have to worry about providing water to nearly 350,000 residents.

“We have more water in our system than we’ve ever had since we’ve been recording,” Aurora Water Resources Management Advisor Joe Stibrich told congressional aides, city council members, city staff and Aurora residents on a tour of the city’s vast water distribution system last week. “We hit 99 percent of our storage capacity about a week ago.”

In total, Aurora Water has more than 156,000 acre-feet of water storage, which could supply the city with years of emergency supply in case of a drought.

The city gets water from three river basins. Half of the city’s water comes from the South Platte River Basin, a quarter comes from the snow melt flows from Colorado River Basin, and a quarter from the Arkansas River Basin.

But Aurora was not always a municipal water powerhouse.

In 2003, Aurora’s water  supply level was at 26 percent capacity, the lowest in the city’s history. The idea for the at-the-time innovative Prairie Waters Project came about in the wake of that severe drought.

The $653-million Prairie Waters Project increased Aurora’s water supply by 20 percent when it was completed, and today provides the city with an additional 3.3 billion gallons of water per year.

The entire system pumps water from wells near Brighton, where it’s then piped into a man-made basin and filtered through sand and gravel. From there, the water is then piped 34 miles through three pumping stations to the Binney Water Purification Facility near Aurora Reservoir, where it’s softened and exposed to high-intensity ultraviolet light. The water is then filtered through coal to remove remaining impurities.

“It’s the crown jewel of our system,” said Stibrich during the tour. “Prairie Waters almost creates a fourth basin for us.”

But even before Prairie Waters, the first “crown jewel” project that allowed Aurora to grow and become the state’s third-largest city, was the one that allowed Aurora to cut most of its water ties with Denver.

Throughout the 1900s and into the 1960s, Aurora relied on the Denver Water Board for its supply. But the partnership between the neighboring cities grew contentious when, in the 1950s, Denver Water imposed lawn watering restrictions on a booming metropolitan area. Part of those restrictions included a “blue line” that prevented some Aurora suburbs from getting permits for new tap water fees.

In 1958, Aurora partnered with Colorado Springs to construct the Homestake Project, located in southern Eagle County in the Colorado River basin. The project was designed to use water rights purchased on the Western Slope that could supply the two cities.

For nearly a decade after the project was conceived, it was mired in legal battles with Denver and Western Slope entities. The first phase of the dam wasn’t even completed until 1967. In the 1980s, Aurora and Colorado Springs unsuccessfully attempted to expand the water collection system within the Holy Cross Wilderness area as part of a phase two plan. 

The issue to this day is divisive, said Diane Johnson, a spokeswoman with the Eagle River Water and Sanitation District during the city’s tour of the reservoir. 

“For people to think we might be having some other dam up here and impacting their access to wilderness is an emotional issue,” she said. 

It was a memorandum of understanding created in 1998 between Eagle County and the two Front Range cities that identifies 30,000 acre-feet of water in the Eagle River basin to be divided into thirds between the three entities that helped alleviate tensions and put the project back on track.

Today Homestake Reservoir provides Aurora with 25 percent of its water, and  Aurora Water officials are looking at various ways to expand their storage to satisfy the Eagle River MOU.

One idea is a small reservoir in the Homestake Valley near the Blodgett Campground. Aurora Water officials said the issue with that plan is having to relocate the winding Homestake Road to a portion of the Holy Cross wilderness to accommodate it. Another alternative, which Aurora Water officials said they prefer, is to create a holding facility called a forebay, in the same valley, along Whitney Creek, that would hold water pumped back from a former World War II military site known as Camp Hale. From the holding facility, water could be further pumped up the valley to Homestake Reservoir.

Aurora Water officials are still working through the various politics of the alternatives, and repeatedly emphasized during the tour that there is no “silver bullet’ when it comes to water storage.

From Homestake, water travels east through the Continental Divide and tunnel where it’s sent to Turquoise Lake, then to Twin Lakes Reservoir near Leadville.

Aurora only owns the rights to a limited amount of storage in Twin Lakes, and that water has to be continuously lifted 750 feet via the Otero Pump Station to enter a 66-inch pipeline that leads to the Front Range.

The Otero Pump station — located on the Arkansas River about eight miles northwest of Buena Vista — is another impressive facet of Aurora’s vast water system, and the last stop on Aurora’s water journey before it is delivered to the Spinney Mountain Reservoir in South Park. With the ability to pump 118 million gallons per day, Otero provides half of Aurora’s and 70 percent of Colorado Springs’ drinking water, delivered from both the Colorado and Arkansas basins to the South Platte River Basin.

Tom Vidmar, who has served as the caretaker at Homestake for nearly 30 years and lives right next to the pump station, said the biggest issue facing Aurora’s water system is storage.

“We actually spilled water out of Homestake this year and didn’t collect (the) full amount we were eligible to take, simply because the reservoirs are at capacity,” Vidmar said during a tour of the massive pump facility. He said the electricity costs alone for Aurora to pump the water add up to around $450,000 a month.

A project Aurora Water officials hope to see come to fruition in 15 years is turning land the city purchased at Box Creek north of Twin Lakes in Lake County into additional storage space so water can be pumped more efficiently through Otero.

“Box Creek is an important project. It gives us more breathing room,”  said Rich Vidmar, who is Tom Vidmar’s son and an engineer with Aurora Water, during the tour. “As we look at storage and where to develop storage, right now we’re looking at spots where we have chokepoints in our system where we’re not able to operate perfectly to get as much water as possible.” 

Just as the state anticipates that its population of 5 million will double by 2050, so does Aurora — and storage will be key to providing water for a city that could potentially grow to more than 600,000 residents in the coming decades.

But the mountains aren’t the only place where Aurora hopes to expand its reservoirs. The city also is looking to expand Aurora Reservoir even further east.

At a July study session, Aurora Water Officials described a feasibility study being conducted to determine just how much water Aurora could store at a future reservoir, which would sit on the former Lowry Bombing and Gunnery Range.

After reading all of the charts and statistics on the city’s water storage capacity and potential to add more supply, Aurora Mayor Steve Hogan wanted one reassurance.

“If there were not another snow flake or drop of water for three years, we could find a way to survive?” he asked Marshall Brown, director of Aurora Water, during the study session.

“We would be making some other recommendations, but yes,” Brown replied.