On quiet streets, in unsuspecting Colorado neighborhoods, among the retirees and young families, illegal activity runs rampant. Operating unchecked, rogue water bandits are the culprits. What’s worse, many of the scofflaws may not even know they’re breaking the law.

The theft takes place in an unlikely location: rain barrels found among backyard flower and vegetable gardens. The problem is so widespread it sparked a big debate at the state capitol.

Update 5.13.2016: Gov. John Hickenlooper has signed legislation finally legalizing rain barrels. Our original story continues below.

Outside a ranch-style home in Fort Collins, I meet with one of the desperados. So she wouldn’t incriminate herself, I agreed to change her name. For this story, we’ll call her Jane.

"We're engaged in illegal activities like collecting water in rain barrels."

“It’s behind there, in that little makeshift wooden contraption that we’ve put around it, mostly just because it was ugly,” Jane says of her backyard contraband: a plastic drum attached to the home’s gutter.

“We’re engaged in illegal activities like collecting water in rain barrels.”

To the chagrin of many this barrel is against the law. In Colorado, using a 50-gallon drum to store the rainwater that falls off your roof is frowned upon. This illegal barrel has a job though, it’s mostly used to water the tulips in the front yard.

“There’s a county sheriff who lives right there and has a stadium view into our backyard and clearly knows that we have it,” Jane says, pointing to a neighboring home, partially hidden by a fence.

Luke Runyon / KUNC and Harvest Public Media

The Colorado Constitution lays out the foundation for the state’s frontier-era water system, and sets forth the idea of prior appropriation. In short, water is delivered to farmers, cities, factories, and other water users, based on when they purchased their water rights. It’s the so-called “first in time, first in right” doctrine. Opponents of the vessels say rain barrels upend and undermine this sacred, fundamental creed, on which decades of water case law have been built.

“There is an impact. We know that there’s an impact.” says state Sen. Jerry Sonnenberg, a Republican from Sterling, and outspoken critic of rain barrels.

After a failed attempt to legalize the barrels, proponents brought the legislation back to life in 2016. Lawmakers passed the bill, HB 16-1005 [.pdf], and Gov. John Hickenlooper is expected to sign it [Ed Note: He did, bill was signed May 12, 2016], making smaller rain barrels, like Jane’s, legal. Homeowners will be allowed two barrels per property, with a combined capacity of no more than 110 gallons.

Sonnenberg voted against it, saying rain barrels have the potential to steal water from rightful users further downstream.

"I could see it being viewed as, 'Oh it's those city slickers, coming to take what's not theirs,' and I think that's a real concern as expressed by the downstream water right users."

“Anybody that does simple math knows that if you have 10 gallons and you hold up another gallon to use somewhere else where it normally wouldn’t have been used, that is a change to the math and how that goes down the river,” Sonnenberg says.

“The question is, how much of an impact is that?”

That question is what drove the debate during the 2016 legislative session. Proponents say the impact is minimal. Opponents say rain barrels sneakily erode the state’s fundamental water law, and to pick away at its protections for water right holders is dangerous.

Already there’s a concern among rural residents that urban centers are swallowing up more water rights, making farming more difficult on the arid plains, says Drew Beckwith, a water policy expert at Western Resource Advocates in Boulder.

“I could see it being viewed as, ‘Oh it’s those city slickers, coming to take what’s not theirs,’ and I think that’s a real concern as expressed by the downstream water right users,” Beckwith says.

Luke Runyon / KUNC and Harvest Public Media

But that concern brings up much larger philosophical questions, Beckwith says, and rain barrels just happen to be a convenient proxy for water use angst.

“I don’t think there is actual harm from these small, residential rain barrels. If you’re talking several thousand gallon tanks at big properties, OK, I can understand that. But not for these small rain barrels.”

Lobbying for the rain barrel exemption, Beckwith asked lawmakers to use common sense to allow them. After the bill’s passage, he rushed out to purchase two brand new rain barrels for his office building. They’re sitting unused, waiting for Hickenlooper’s signature.

Beckwith doubts there will be a rush on rain barrels given their impending legality, but even if more backyard gardeners turned to using them, it’d be a drop in the proverbial bucket. Plus, he adds, most of Colorado's stored water supplies, held in reservoirs and divvied up to farmers and cities, comes from melting snowpack, not from rainfall.

“Fundamentally it’s never been about the actual water savings,” Beckwith says. “It’s about the fact that someone with a rain barrel begins to pay more attention to when it rains and when it doesn’t rain and they begin to understand that water is a limited resource and that act of managing your own water builds your own conservation ethic. Really it’s a tool to build a conservation ethic in the urban centers.”

Enthusiasts will still need to wait to use their barrels if they want to stay under the letter of the law. The state engineer’s office is in charge of enforcing water law, and I couldn’t find a single instance of a rain barrel user being cited, fined or taken to water court for using one.

Back in Fort Collins at Jane’s house, it’s just about to rain, and her illegal rain barrel is ready to get to work. She brought hers with her when she moved to Colorado from Illinois.

“Water’s a big concern out here in the West and [I was] thinking it would be encouraged here. To find out that actually it’s illegal was kind of shocking.”

Maybe soon those anonymous rain barrel ne’er-do-wells will be vindicated, feeling comfortable enough to come out of the shadows and water their tulips without looking over their shoulders.