Nov. 19–A few times a week, the vast protected zone of far west Miami-Dade County known as the Lake Belt is shaken by controlled explosions set off by miners to loosen lucrative limestone rock within the big, water-filled pits that define the area. All day long, trucks laden with tons of crushed rock bound for construction projects rumble through a dusty moonscape along Northwest 41st Street just west of the turnpike.

That is where the owners of Aventura Mall and the Fontainebleau hotel propose to build an upscale shopping mall, IMAX theater and a five-acre water theme park.

The push by Turnberry Associates, which would require moving the county’s Urban Development Boundary, has run into a veritable rock wall of opposition from a broad coalition of strange bedfellows — not only from environmentalists and anti-sprawl activists, but also from the mine operators themselves. The two groups have often been at odds in the past over the impact of mining on groundwater quality.

Naysayers also include the county’s planning department and planning board, the local community council and Miami-Dade Mayor Carlos Gimenez. All have come out strongly against the Turnberry request, which is up for a vote by the county commission on Wednesday.

Turnberry contends that moving the line, which limits urban expansion into the western and southern reaches of the county, is justified because residents of Doral and Northwest Miami-Dade need a big family-friendly entertainment, dining and shopping venue that would not fit anywhere else in the area. But county planners say there is plenty of land available elsewhere within the existing UDB, and question the need for another mall in an area that already boasts two mammoth shopping centers.

The critics say the plan for Doral Crossings would shoehorn an utterly incompatible development into a carefully regulated zone that explicitly excludes urban uses to protect both the rock mining industry and the county’s primary, most pristine reservoir of drinking water, which happens to lie just below the surface. The still-controversial regulatory scheme, the result of years of litigation, legislation and negotiation, is meant to protect mining operations while ensuring they do not contaminate the aquifer within the Northwest Wellfield Protection Area.

“It’s going to be our major source of water,” said Deputy Mayor Jack Osterholt. “In the hierarchy of needs, it’s at the top of the food chain. We have to make sure, almost at any cost, that that stays available to us so we can provide drinking water

“I don’t think anybody could justify the need for this project.”

Attorneys for the rock miners say that while the Soffer family that controls Turnberry can put their project somewhere more suitable, the nine mining operations in the 79-square-mile zone, which provide half the rock material used for construction in Florida, can’t go anywhere else. They fear commercial encroachment could push them out. And they note that explosions and family fun don’t mix well.

“We need to be where the resources are found,” said Kerri Barsh, who represents the Miami-Dade Limestone Products Association and four mining companies.

But a team of lobbyists and consultants for Turnberry is far more sanguine.

At a hearing before the county planning board earlier this month, Jeff Bercow, an attorney representing Turnberry, said there is “absolutely a need for this project,” citing a county study that supported development of an entertainment district in the Doral area. But county planners said in an analysis that Turnberry “grossly mischaracterized” the study, which pointedly looked at sites inside the UDB only.

Turnberry’s transportation consultant, Cathy Sweetapple, meanwhile said there would be “no issues whatsoever” in mixing shoppers headed for the mall and heavy rock-mining trucks and equipment on the local roads, which would simply be widened.

And engineering consultant Ed Swakon dismissed concerns over the wellfield. “We don’t want to harm the wellfield,” he said flatly, promising that all stormwater be retained on site to allay those concerns.

As for the blasting, Bercow said, no problem there, either: The mall and water park buildings would be designed to withstand the vibrations from the explosions and the Soffers and their tenants would promise not to sue.

Hogwash, said attorneys for the rock miners. They say having commercial development as close as 120 feet from a mine would sharply curtail, if not do away with, its ability to do blasting. Strict regulations enacted to protect urban neighborhoods and shopping areas just on the other side of the UDB, which in the Lake Belt area now runs along the turnpike, sharply limit the radius within which strong vibrations from blasting can be felt.

Moreover, they say, state law prohibits rezonings to allow incompatible uses within a mile of the Lake Belt.

Miguel De Grandy, a longtime attorney and lobbyist for some of the rock miners, turned the developers’ argument on its head.

“How would they feel, if there was a hypothetical 200-acre green space by the Aventura Mall, to permit a rock-mining operation?” he said. “They would scream bloody murder, because it’s clearly not compatible.”

Turnberry wants to move the UDB west past the turnpike to encompass two large vacant parcels flanking Northwest 41st Street. The parcels border areas now being mined or designated for future mining under the Lake Belt plan, Barsh and De Grandy say.

The county property appraiser’s website shows Turnberry paid $20 million for the southern parcel in 2005, the height of the previous development boom, though it’s now assessed at under $5 million. The northern parcel, assessed at $525,000, is owned by another development group, though opponents of the project say they believe Turnberry has a deal to buy it. A Turnberry representative did not return a phone call requesting an interview.

A county analysis says Turnberry wants to change the designation of the parcels, now restricted to open land, to office and commercial, and build around 850,000 square feet of retail and a water theme park of at least 4.5 acres. Turnberry also asked that the two properties be carved out of the wellfield protection area to allow construction.

But Miami-Dade planning director Mark Woerner, citing the analysis, concluded the Turnberry proposal violates a long series of county regulations and policies enacted to limit urban sprawl and car dependency, conserve natural areas and water resources like the wellfield, and promote development of walkable communities served by transit.

Bercow, the Turnberry attorney, accused planners of going “overboard” in their analysis.

Woerner, however, said county planners also concluded there is enough land for commercial development inside the UDB beyond the year 2030.

One of those areas: the so-called doughnut hole just south of the Lake Belt, where the county commission last month expanded the UDB to encompass 520 acres of land already surrounded by urban development.

Efforts in the past to expand the boundary have been sharply contested by environmentalists, and Gimenez and some commissioners have vowed to hold the line in all but the most unusual circumstances. Last year, Miami-Dade voters approved a county charter amendment requiring assent of at least nine of the 13 commissioners to move the line.

That would appear to present a high hurdle for the Turnberry plan. But opponents say the developers may be hoping to get commissioners to agree to “transmit” their application for review by development-friendly regulators in the administration of Gov. Rick Scott in Tallahassee. The vote to transmit would require only a simple majority of commissioners.

The commission would still have to approve moving the line, but a positive evaluation from Tallahassee could improve its chances politically, they say.

But the opponents say the application has so little merit it should not even get that far.

“Why do that when we already know it’s not consistent with Miami-Dade’s laws?” said Sara Fain, executive director of the Everglades Law Center. “We don’t need the state to tell us that. We should stop this right now.”