It took six months to completely fill Crystal Lagoon with 37 million gallons of water, and now St. Johns County can call itself home to the largest man-made lagoon in the nation.

That is, at least until a 20-acre lagoon in the works at a resort hotel in Las Vegas finishes up in the next couple of years.

Regardless, the massive water amenity in the master-planned community Beachwalk gives its residents bragging rights. They, along with their guests, will be the only people allowed access. And since the community only has about 800 planned single-family residences, access is pretty exclusive when compared to a resort hotel's thousands of visitors it can get in any given month.

"You're not just getting a community to live, you're getting a private beach club," said Beachwalk developer John Kinsey, who marked the milestone Monday by pouring a bucket of water, the symbolic "last gallon," into the lagoon.

Now that the community's focal point is complete, people can expect the rest of the community to develop pretty fast.

So far, about a couple of dozen of homes are finished, and some residents will be able to move in as soon as this week. However, they won't be able to use the lagoon until late August or early September, after safety checks and clean up are complete.

Homes, which are being built by Lennar, Americrest Luxury Homes and Vintage Estate Homes, range in price from around $400,000 to more than $1 million. A typical house has community fees ranging from around $500 to $550 per month.

Only one multifamily development is planned for Beachwalk. Earlier this month, Summit Contracting Group announced it was awarded the $33 million contract to build a 348-unit, Class A apartment complex. But renters in the complex won't have access to Beachwalk's club membership, and only 25 residents of the complex can visit the lagoon each day.

Beyond the completion of residential, which is expected in 2021, about 130 acres of retail, 100 acres of light industrial and a 70-acre site for a high school will be developed over the next several years. Medical and office space is also planned. In addition, Kinsey and his team are working on getting deals with a hotel franchise and movie theater.

Beachwalk is one of a few master-planned communities that have sprung up in northeast Florida in the past decade. Others include nearby Nocatee, Nassau County's Wildlight and eTown, in Duval County. Kinsey believes the trend toward communities with amenities and a mix of residential, retail and office has to do with a generational shift from young homebuyers.

"This generation is looking for something different in houses, the same way they're looking for something different in retail," Kinsey said. "People want to have an experience."