SANTA ROSA BEACH — Walton County commissioners have unanimously approved the issuance of a development order for a 24-story, 82-unit condominium project on 4.66 acres at the Sandestin resort and residential community in Miramar Beach. 

Last week's approval, which allows the project on the south side of U.S. Highway 98 in Miramar Beach to proceed, still requires that it meet standards for issuance of construction and other permits.

The approval for The Cascade at Sandestin came only after commissioners got some assurance that installation of the pilings upon which a parking deck for the multi-story structure will sit won't compromise existing nearby residential structures.

Background on the development:Proposed Sandestin 82-unit condo causes flooding worries for neighbors along U.S. 98

What makes a story?:Walton planners approve new definition of building stories. Here's what happens next.

Commissioner Danny Glidewell, citing reports that nearby installation of pilings may have contributed to the collapse last year of a condominium tower near Miami Beach, raised the issue for the proposed Sandestin project.

"There are at least allegations that the Surfside incident in Miami was caused by construction next door and driving pilings," Glidewell told local attorney Dana Matthews and Dean Burgess of Emerald Coast Associates, the local civil engineering firm working on the project.

"Y'all are promising, certifying, guaranteeing that that's not going to happen with those (condominium residential units) to the south (of The Casade)?" Glidewell asked.

"We're very aware of all that," Matthews added, citing the structural engineering expertise associated with the project.

"Are they going to have a way to monitor those (nearby) buildings just to make sure?" Glidewell pressed. "We don't want a Surfside-type incident."

Matthews told Glidewell that he didn't know of any specific plans for a monitoring program, but said that the half-dozen residential buildings within several hundred feet of The Cascade have had their engineers involved in discussions.  

Representatives of those buildings wanted to know about piling installation and have been kept apprised of plans for the upcoming project, Matthews added.

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Burgess told commissioners that the concern with the Surfside incident was that adjacent buildings had used "vibratory pile installation" or "driven impact pile installation."

The piles being installed for The Cascade "are what's called an auger cast system. Basically, they auger down. It does not cause any vibration or impact, and as they extract the auger — the auger is hollow in the middle — they shoot concrete, and as the auger is extracted, the concrete displaces the auger," Burgess said. "It's a far less disruptive system as far as vibration and impact to the neighbors."

In other recent development-related action, Walton commissioners have set an adoption hearing for April 12 to have a final vote on a proposed amendment to the county's land development code that changes the definition of what constitutes a story of a building.

The issue arose a few months ago in connection with concerns regarding a planned six-town home development on a little more than 0.75 acres on County Road 30A at Blue Pine Boulevard near Blue Mountain Beach.

Under the existing land development code definition of a building story, the townhomes planned for the tract are considered three-story structures because the bottom story, which the developer has indicated won't be habitable, but will be used for parking and other purposes, isn't counted as a story.

That, in turn, affects how far a building must be set back from a property line. Residents of a single-family subdivision adjacent to the planned development contended that the less-stringent setback requirement for a three-story structure — rather than counting the proposed townhomes as four stories — creates privacy issues for them by allowing the structures to be built closer to the boundary between their homes and the townhomes.

An amended land development code won't help those homeowners, because the townhome project began under the current code language. But it could help other homeowners faced with adjacent development because the proposed amendment would define a story as "an above-grade habitable or uninhabitable floor level within a building."