Sometime this month, Honolulu Zoo elephants Mari and Vaigai will take a short stroll to their newly expanded home that is 17 times larger than their old enclosure.

The new $12 million elephant exhibit, measuring 1.4 acres, features an open dirt space, tall concrete planters, shady coves and two 55,000-gallon waterfall pools with overlooking viewing areas. It is skirted by a walkway leading from the gharial display to the African Savanna section, and is surrounded by an electrified barrier behind a chain-link fence.

Construction on the new elephant enclosure is 95 percent done, with a few more tweaks needed to the water filtration system. A grand opening will be held in December, although a date has not been announced.

“Now we’re on elephant time,” said zoo Director Manuel Mollinedo.

Mari, 35, and Vaigai, 25, two female Asian elephants, are expected to undergo some stress during the move and will need time to adjust to their new surroundings before the exhibit opens to the public. Elephant keepers have been taking the pair of pachyderms on strolls toward the new enclosure to get them ready, although they have not walked the full distance yet.

“I’m positive they’re going to like their new home,” Mollinedo said. “It’s so much larger and nicer than the old exhibit.”

The new elephant habitat is nearing completion more than 12 years after the city first proposed the improvements.

For the past 20 years, Mari and Vaigai have lived in a humble space measuring just 3,600 square feet with a concrete floor, palm trees painted on a wall, a small moat and a holding pen in back.

The new space is much more open and contemporary in design; it’s sort of like moving from a small, urban cottage to a modern-style ranch home.

The waterfall pools are the highlight (and their filtration system the largest investment). The concrete planters have textured surfaces ideal for the elephants to rub up against when they have an itch to scratch. Saplings in the planters will mature in coming years, offering a canopy of shade.

Mollinedo said he plans to offer the old elephant space to displaced wild donkeys from Hawaii island until new animals for the zoo can be brought in — possibly tapirs, a hooved herbivore from South and Central America.

BEHIND THE new elephant exhibit is a large holding area outfitted with an elephant “tamer” — an apparatus that holds an animal in place while it undergoes medical work.

That holding pen will help the Honolulu Zoo comply with a long list of requirements needed to receive accreditation by the Association of Zoos and Aquariums. The organization tabled the facility’s accreditation in March and will return for another inspection by the end of the year.

Both the front and back areas have gates that can shut one side off from the other, which should make moving the elephants around much easier, according to Mollinedo.

Honolulu Zoo eventually hopes to bring in a bull elephant to breed with the females. Regardless of the possible addition, Mollinedo said two more employees will be hired to help care for Mari and Vaigai alongside the three already on staff.

Though the new elephant habitat is considerably larger than the existing one, an animal rights group says it’s still not big enough.

In Defense of Animals, based in San Rafael, Calif., listed Honolulu Zoo among the top 10 worst zoos for elephants in 2009 and 2010. A new list is due out in January.

The nonprofit group said Mari and Vaigai were crammed into their space, wreaking havoc on their physical and psychological health. The group also is concerned about the use of bullhooks to manage the animals.

Catherine Doyle, elephant campaign director for In Defense of Animals, said elephants need significantly more space — preferably 400 to 500 acres as provided by sanctuaries — to thrive as they would in their natural habitat. She is also concerned about the prospect of bringing in a male elephant, which would negate the space gain from the new exhibit.

“The zoo needs to focus on doing the right thing for Mari and Vaigai, and that’s to give them the entire space in the new exhibit,” Doyle said. “There just isn’t enough space to hold a male elephant, which is more powerful and dangerous to handle.”

Mari arrived at Honolulu Zoo in 1982 from Hyderabad Zoo in India, and Vaigai joined her in 1992 from Arraign Anna Zoo, also in India. Both came to Hawaii through the efforts of the Watumull family, longtime business and community leaders.

The two animals are in good health, according to Mollinedo, with the exception of being a little overweight.

He expects them to exercise more in their new home, and said he disagrees with In Defense of Animals that Mari and Vaigai are mistreated.

“We have a group of very dedicated keepers that take care of the elephants … They are extremely passionate about those animals,” he said.

With the new habitat, elephant workers will have less contact with the animals, a philosophy that is being adopted by zoos across the nation.

Mollinedo said Mari and Vaigai are luckier than zoo elephants in most other locations because they can stay outdoors year-round in Hawaii’s warm climate and don’t have to be shut up in a metal barn during the winter.

They are fed a combination of hay, grasses and foliage, and as a special treat, tropical fruit.

The new elephant habitat is an accomplishment for the zoo, Mollinedo said.

“It’s a vast improvement over what the elephants have had,” he said. “It’s an exhibit that can hold its own against many mainland exhibits for elephants.”