ALBUQUERQUE — Decades of negotiating water rights, installing miles of pipeline and building a state-of-the-art treatment plant culminates today with the first drops of purified river water reaching taps throughout New Mexico's largest metropolitan area.

The $400 million San Juan-Chama Drinking Water Project will supply up to 90 percent of the Albuquerque area's future water.

"It is really Albuquerque's future and New Mexico's future in the sense of providing a water supply and then protecting the aquifer in the long term," said John Stomp, who manages the project for the Albuquerque Bernalillo County Water Utility Authority.

Stomp guided a tour of the project's diversion dam, pump station and water treatment plant Thursday, a day before dignitaries were set to pull a lever and release cleaned water from the plant into the city's pipes.

An eight-mile pipeline transports water diverted from the Rio Grande to the treatment plant.

There, the water is purified as it moves through an elaborate system of pipes designed to remove particulate matter, sediment and bacterial and microbial contaminants. The cleaned water is then blended with groundwater to supplement drinking water supplies.

The system, which is constantly monitored through a battery of sensors and computers, is capable of processing 90 million gallons of water each day.

Stomp said San Juan-Chama water will initially make up about a quarter of the drinking water supply. That will increase over the next year to ease pressure on the aquifer beneath the city.

Until now, Albuquerque relied solely on an aquifer — an underground reservoir — that was once thought to be infinite.

But when city officials learned decades ago that the aquifer's life span was limited, they made plans to divert water from the San Juan and Chama rivers in the north to the Rio Grande, which travels through the heart of the city.

"There's such a long history and so many people involved with bringing the water and making this happen. It's amazing," Stomp said.

Albuquerque has rights to 48,200 acre-feet of San Juan-Chama water per year. An acre-foot, about 326,000 gallons, can meet the annual water needs of one to two U.S. households.

Several towns and tribes also contract for the San Juan-Chama water, including Taos and Santa Fe.

Stomp said more communities in the West are being forced to look at surface water sources because drought and growing populations are taxing their groundwater supplies. He said more than two-thirds of America already relies on surface water.

Local water officials said the San Juan-Chama project is unique in that it transfers water from one basin — the Colorado River basin — through a network of diversion channels and tunnels to another basin in the Rio Grande Valley.

The system also was designed to protect habitat along the Rio Grande and the endangered silvery minnow. Sections of the diversion dam can be raised and lowered to allow fish and sediment to continue downstream, and a side canal was built to allow fish to swim around the dam.

Special sensors were installed in the canal to help federal biologists track the minnows, and screens at the end of the intake channels will keep minnows and their eggs from entering the pipeline system.

"We allow the fish to move around so that they're not impeded by the structure," Stomp said. "We tried to build in as many features as we could to keep the river functioning like a river, and keep the fish and wildlife protected at the same time we're taking our water out."

The project did hit a snag earlier this year when a fungus known as black yeast was found in a few bottles of water that were handed out as part of a marketing campaign to promote the San Juan-Chama project.

Officials determined that the contamination happened after the water left the plant, but bloggers had a field day, describing the water as everything from "bad news" to "el stinko."

Stomp said the water authority has gone to great lengths to ensure San Juan-Chama water is clean and meets drinking water standards. He said most residents won't notice a difference once it starts flowing through their taps.

City officials see the project as a blessing, but they point out that San Juan-Chama water is only part of the solution to ensuring Albuquerque's water needs are met long into the future.

Conservation is the other key, Stomp said. "I think we all tend to take water for granted, especially in Albuquerque. ... People turn on their taps and don't even think about water," he said. "I wish people would make decisions day by day, thinking about saving water, as opposed to just taking it for granted."