St. David Cienega in the San Pedro Riparian National Conservation Area

Dormant vegetation of the St. David Cienega marshland meets the lush green of the San Pedro Riparian National Conservation Area. Environmentalists are concerned a proposed 28,000-home development in Benson could dry up the marshland.

BENSON — A proposed 28,000-home development in Benson is heading for the City Council with a unanimous recommendation from the city’s Planning and Zoning Commission.

The commission voted 6-0 in favor of a Phoenix development firm’s preliminary plan for Villages at Vigneto despite requests from many speaking in the audience to hold off.

The council will vote on the development plan on Monday.

Those seeking a delay wanted more information about the project’s impacts on the water table and the San Pedro River. It would be “reckless” to assume the development’s water pumping won’t affect the river without getting more information, said an advocacy group representing the rural Cascabel area.

“No one has assessed the potential effect on the San Pedro River as groundwater levels decline,” said a statement from Cascabel Conservation Association that was read by a member at Tuesday night’s commission meeting.

“The Santa Cruz River in Tucson perished because of the continued pumping of groundwater, an important lesson for those who propose large-scale development in other riparian areas.”

But many others urged the commission to support the project as a boon for economic development.

The developer’s representative, Mike Reinbold, also pointed out — and many commissioners echoed this comment — that the property already has zoning to build 60,000 homes. So the current plan would result in the use of much less water than the earlier proposal would.

“I’ve lived here for 50 years and I’ve seen a lot of developers come through and seen a lot of lots with nothing on them. This is the first time I’ve seen a definite community plan for a project,” Commissioner Bob Baden said.

“This is probably one of the best proposals I’ve seen since coming to town.”

Numerous businesses closed in Benson over the last two or three years, Baden added. “I’d personally like to see Benson grow.”

Reinbold, of El Dorado Holdings Inc., testified the project would use about 6,200 acre-feet of water.

That compares to about 9,800 acre-feet that the project’s original developer, Ernie Graves, was planning to use at what was formerly known as Whetstone Ranch, Reinbold said.

He said in response to a commissioner’s question that about 2.5 persons would occupy a typical home, making for a total population of about 70,000.

If it’s approved, the project is slated to break ground in late 2015 or early 2016. He promised more detailed answers to questions about water in two months.

“If you just use water as a way to stop growth, that’s not a smart thing,” he told the audience of about 40 people.

But the Cascabel conservation group cited a recent study of the middle San Pedro River area that found much of the area’s groundwater is very old, having fallen as rain anywhere from 1,700 to 35,000 years ago. The study was published last year in the Hydrogeology Journal.

“Withdrawal rates from this aquifer may already be unsustainable,” the Cascabel association said. “It would be prudent to examine this issue of sustainable withdrawal more thoroughly before increasing the rate of groundwater withdrawal by a large factor.”


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Contact reporter Tony Davis at tdavis@tucson.com or 806-7746. On Twitter:

@tonydavis987