Glynn County commissioners voted Thursday evening to allow development of eight super-exclusive and very pricey homes on Sea Island’s southern spit of land.

But a rising Atlantic Ocean, huge tides and erosion could threaten the homes whose lots alone run between $3.5 million and $5.5 million. Sea Island is a prime destination for well-heeled Atlantans who can afford suites at The Cloister costing $1,000 a night.

State and federal environmental officials, who'll ultimately decide whether the homes are built, have also raised concerns over the project's impact on nesting sea turtles, piping plovers and the beach at nearby St. Simons Island. They're reviewing the Sea Island Co.'s request for a permit to build an offshore groin, or wall, to protect the spit's beach.

Legal and regulatory sign-offs could delay groin construction for five years. The Sea Island Co., though, can now begin selling the home lots.