The world’s largest casino will be getting a family-friendly neighbor: an indoor water park and resort.

The Mashantucket Pequot Tribe — owners of Foxwoods Resort Casino located in nearby Ledyard, Conn. — and Great Wolf Resorts announced plans on Thursday to build the park, which will be called the Great Wolf Lodge and resemble Great Wolf’s nine other water parks across the country and in Canada. The move comes at a time of general expansion for Foxwoods, which will open a $700 million addition to the casino in the spring.

Great Wolf spokesperson Jennifer Beranek stressed that the agreement is not final and only constitutes a “letter of intent,” but the tribe was more certain about the details.

Tribal spokesman Bruce MacDonald said the Lodge will be separate from Foxwoods. Unlike the casino, it will be built outside the bounds of the tribe’s reservation in southeastern Connecticut. MacDonald said the tribe envisions an environment where a family can split up and sample the various adult- and family-oriented activities available.

“Let’s imagine that there’s a family coming to the Great Wolf Lodge,” he said. “Maybe one of the family likes to golf, so they go off and golf. And maybe one spouse or the kids would like to go to our world-class tribal museum. Then people can go to Foxwoods.”

MacDonald declined to say how much money the tribe thinks the water park can bring in, but said it was a “good solid economic venture.” At the very least, the addition of the Lodge will allow the tribe to potentially broaden its economic base, attracting families who might be turned off from going to the world’s biggest gambling center.

The concept of the indoor water park is a relatively new one, said Tim O’Brien, author of several amusement park guides and vice president of publishing and communications for Ripley Entertainment, which is best known for the television show “Ripley’s: Believe It Or Not.” He said the first parks opened in the early 1990s.

“I would say there are now close to 75 legitimate water park resorts in the U.S.,” he said. “Not everybody’s doing it, but it is a trend.”

O’Brien and his company have partnered with Great Wolf to open a Lodge in Niagara Falls, Canada. As he described it, the water park is part of a larger hotel. There are game rooms and arcades, guest suites and restaurants. The water parks all feature multiple water slides, pools and a “four story treehouse water fort,” according to the company’s Web site.

“It’s like a cruise ship,” O’Brien said. “You never have to walk out the front door.”

MacDonald would not specify a time frame for beginning construction on the Lodge, but said the tribe was eager to begin work.

It does not appear as though the tribe will have much competition for indoor water parks in the tri-state area: There are none. But O’Brien said people might not want to go to the new Lodge if there is nothing around it but the casino.

“Is there enough to bring a family there?” he said. “In Niagara Falls we’ve got this lodge but we’ve also got this wonderful thing called Niagara Falls. It’s a family-friendly area. Is [the Lodge] enough to keep somebody driving 300 miles?”