(NBC NEWS) In the Arizona desert, there's a river that never stops running, providing water to millions.
But it's facing threats that local people there are trying to stop.
Clearing trees and brush on these banks is part of a grassroots campaign to save the Verde River, a major tributary of the Colorado.
"This river is the lifeblood of our communities," said Anna Schrenk with friends of Verde River Greenway.
The Verde is exceptional in this desert, always flowing and often flooding, to regenerate habitat along the riverbed.
"The Verde River supplies water to 2 million people in the phoenix metro area. So the health of the Verde river is not only important to the communities in the Verde Valley, but also to that Phoenix metro area," Schrenk said.
There are serious threats to the Verde, like invasive plants that kill native vegetation and block the river's natural flow.
"And just since 2012 we have removed invasive plants from over 8,000 acres in the watershed," said Schrenk.
Another threat: is population growth, development and agriculture in the Verde Valley, pumping out ever more groundwater that would otherwise flow into the river.
"We have a pretty wide range of programs we do with agriculture, with municipalities, and with other industrial users to try to put more water into the river and protect the flows that we have there," said Kimberly Schonek with The Nature Conservancy.
Another strategy is crop-switching.
Convincing farmers to choose profitable crops that use less water than corn or wheat, like barley.
All of this is starting to make a difference.
"We're trying to engage our local, young adults and our returning veterans to do some of this on-the-ground work," Schrenk said.
Critical help for a very special river,from people who want to keep it that way.