PHOENIX - Homebuilders have lost another bid to stop federal agencies from designating two stretches of the Santa Cruz River as "navigable."

In a 21-page ruling, U.S. District Judge Ellen Huvelle never addressed the question of whether the parts of the river in question fit the legal definition. Instead, she ruled the National Association of Home Builders had no legal standing to challenge the decision by the Army Corps of Engineers and the Environmental Protection Agency.

The same is true, the judge said, for the Southern Arizona Home Builders Association and the Home Builders Association of Central Arizona.

Huvelle said affected property owners would have the right to challenge the designation.

But the judge said the developers who were part of the lawsuit failed to show they had been harmed by the federal action. And that, she said, gave them no more right to sue than the associations.

The issue is more than academic.

Once a stream is determined to be navigable, it falls within the scope of the federal Clean Water Act, which restricts any discharges into water that eventually winds up in those streams, covering everything from pollutants to rocks and sand.

SAHBA President David Godlewski said this isn't just an issue for those who own land near the river.

He said much of the developable land in Southern Arizona is near one or more washes that eventually drain into the Santa Cruz River. That, he said, makes those developers subject to the additional restrictions.

Godlewski said he wants to confer with attorneys before deciding whether to appeal. But he said it should not be necessary for a developer to face imminent harm, or actually to have been affected, before the designation can be challenged.

"People are limited in the development of their property because of the determination," he said.

The fight involves two areas of the river designated as navigable - a 20-mile stretch from Tubac to Continental and from Pima County's Roger Road sewage treatment plant to the Pinal County line.

Attorneys for the homebuilders said in the suit that the EPA designation "is unsupported by credible evidence demonstrating that the Santa Cruz River is currently, or ever was, susceptible to use as a highway for water-borne interstate commerce." They said neither stretch has any water for much of the year, with its "base flow" consisting of treated sewage.

A similar lawsuit by the homebuilders was previously thrown out of court due to lack of standing. In a bid to sidestep that problem, the case was refiled with declarations of three property owners who said they were personally affected.

But the judge said none of them was able to show they had been the subject of an enforcement action for discharging water without a permit into a navigable stream, and no evidence they had been denied a permit.