Riviera Lakes Joint Venture originally envisioned student housing on the site, and a seniors-only community is still in the mix to the tune of 2,200 new dwellings. But the added concept for what’s called Vina del Lago sees a market for a spa and conference center. City officials are just now evaluating what to encourage for this area of Southport, just outside city limits, but likely to be annexed. Two home builders already have plans for 6,000 homes. Traffic in the fast-growing area is a concern, and the levee at the city’s southern edge would also need to be strengthened.