By Kathy Finn

NEW ORLEANS (Reuters) - Perhaps no other city in the United States is as well-suited as New Orleans to wed a scientific discussion of environment with a celebration of the occult.

That's exactly what unfolded on Saturday at "Anba Dlo," an annual New Orleans festival where prominent scientists joined with practitioners of the voodoo religion to look for answers to the challenges of dealing with water.

In "The Big Easy," a low-lying Louisiana city devastated by Hurricane Katrina in 2005 and threatened by the BP oil spill of 2010, water is a subject nearly impossible to ignore.

Four representatives of Rand Corp, the global consultancy that helped develop the state’s master plan for coastal restoration, joined a dozen environmentalists, architects and policy specialists who took part in Anba Dlo, which translates from a Haitian dialect as "beneath the waters."

The event was held at a community center in the New Orleans neighborhood known as Bywater, one of those pounded by Katrina.

Against a backdrop of elaborate Halloween decorations and voodoo-themed performance stages, the discussion centered on how South Louisiana, by necessity, is developing new models for water management.

"I've spoken at a lot of conferences around the country, and this festival is pretty unique," said Jordan Fischbach, a policy researcher for Rand in Pittsburgh. "But then, this is New Orleans," he added with a laugh.

The festival, now in its seventh year, is the brainchild of Sallie Ann Glassman, a longtime New Orleans resident who is a high priestess in the Haitian religion of voodoo and an anti-poverty activist.

In 2006, the year after Katrina, Glassman and her husband, real estate developer Pres Kabacoff, built the multipurpose community center in the devastated Bywater neighborhood.

Her voodoo shop – where Glassman holds readings and healings, and dispenses talismans, voodoo dolls and chicken foot fetishes – became the first tenant of the new "healing center," which in time came to house a restaurant, fitness center, fresh-foods grocery and performing arts space.

Glassman regularly uses the center to stage events aimed at strengthening the neighborhood, and she sees the Anba Dlo festival as a natural way to focus attention on one of the biggest problems facing New Orleans and the region.

"As a priestess, it's my work to bring balance and healing and wholeness to the community, so this is absolutely in keeping with my work," she said.

During the afternoon symposium, which drew about 100 people, both Katrina and the BP oil spill figured prominently in the discussion about how Louisiana can restore its coastal marshes.

Katrina and other storms seriously damaged the coast, and the oil spill led to massive litigation that eventually will funnel billions of dollars in penalties to Louisiana to help pay for the damage.

"Dollars alone won't make anything happen, but dollars do matter," Mark Davis, director of the Tulane University Institute on Water Resources Law and Policy, told the symposium as he discussed the estimated $50 billion cost of implementing Louisiana's master plan for rebuilding its coast.

As twilight fell on New Orleans, the scientific discussion faded into the background and hundreds of costumed revelers gathered for a parade that would launch a night of live music, psychic readings and acrobatic performances.

At midnight, Glassman was slated to perform a ceremony in which she would invoke the voodoo mermaid spirit known as La Siren.

"She is the force of the great ocean and power of water to work away at the hard rock of reality," Glassman said.

Glassman prays to the spirit "partially to apologize for what we've done to the water, but also to bring us guidance to fix the damage and live more in harmony with the planet," she said.

(Editing By Frank McGurty and Nick Zieminski)