HAWAI'I KAI — A proposal to dump dredged material on an islet in Hawai'i Kai Marina that's home to endangered Hawaiian stilts is creating a tug of war between area residents who maintain that the 3-acre islet should be off-limits and a marina group that wants to use it as a disposal site.

Three years ago, the Hawai'i Kai Marina Community Association began seeking a permit from the U.S. Army Corps of Engineers to use two islets in the marina area to store dredged material. After submitting the application, Hawaiian stilts, or ae'o, were spotted nesting on one of the islets.

Ensuring that the birds are protected in a suitably sized habitat, some area residents say, is well worth the permit process delay. Association members, charged with managing and maintaining 13 miles of waterways, counter that the more time the process takes, the more sand and silt will build up in the marina, particularly along the main accessway at the mouth of the marina under the Kalaniana'ole Highway bridge.

The association wants permission to dredge any time it needs to over a 10-year period and dump the dredged material on either Rim Island 1 or Rim Island 2, rather than obtaining Army Corps of Engineers permission for each maintenance dredging.

After the last dredging at the mouth of the marina, completed about three years ago, sand was used to replenish the beach at Portlock, and the three bays under the bridge were opened up for waterway traffic. Today about 1 1/2 bays are open, said Steve Carr, Hawai'i Kai Marina Community Association president.

"It's a potentially hazardous situation," Carr said. "The more openings we have, the better. People have to wait to come in and wait to go out."

Rim Island 2, an uninhabited area, is home to a wide variety of birds, including the ae'o, which likes to live in marshy mudflats free of dense vegetation and predators. Because the ae'o has been documented on the island, the U.S. Fish and Wildlife Service was called in recently for consultation to comply with the Endangered Species Act. The bird was first spotted on Rim Island 2 in the late 1990s, Carr said.

The federal agency intends to make recommendations on a suitable habitat for Rim Island 2 that would both enable the marina association to use the islet for dumping dredged materials and protect the birds. A study and mapping of the islet's pond and mudflat areas are under way, said Gordon Smith, a Fish and Wildlife Service biologist.

"When the stilts find a place they can feed and live, it's very important to protect that habitat," Smith said. "With some engineering and foresight, the association can accomplish their goal of dredging and continue to protect the habitat."

Some residents are calling for a habitat plan that would prohibit the dumping of more dredged materials on Rim Island 2.

"If it were up to me, I'd keep Rim Island 2 out of the permit," said Hawai'i Kai resident James Dittmar. "Rim Island 2 is a wonderful habitat. I want to save it as a wildlife habitat for the future generations in East O'ahu."

Nearly 20 endangered Hawaiian stilts have been spotted by residents who have written letters in opposition to dumping dredged materials on the islet to Fish and Wildlife and the Corps of Army Engineers. While the marina group has drafted a Rim Island 2 waterbird habitat management plan that addresses conservation matters, Dittmar wants the Corps of Engineers to require the association to conduct an environmental impact study before making decisions related to using the islet as a disposal site.

The marina group's designated storage areas for dredged materials are Rim Island 2, Rim Island 1 and a 2-acre parcel in the back of the valley near the Kamilo Nui farmers area, which has not yet been used. The association has said it may need to dump dredged material on Rim Island 2 because of dwindling storage space on the smaller Rim Island 1.

Hawaiian stilts — a slender wading bird that grows to about 16 inches in length with a black and white forehead and white belly — are endangered mostly because of a loss of wetland habitat. Over the years, as various mudflats have been filled in, habitats have grown over with invasive species, according to the Fish and Wildlife Service.

The Hawai'i Kai Marina, also called Kuapa Pond, was a fish pond before the mudflats were transformed more than three decades ago into waterways and future home sites. The work was done years before the federal Clean Water Act was enacted.

"The numbers of Hawaiian stilts are low and we want to protect against further loss by protecting the habitats," Smith said.

Stilts can still be found throughout the Islands except Kaho'olawe. The Fish and Wildlife Service last year estimated that about 1,200 birds were on Maui and O'ahu. In addition to the Hawai'i Kai Marina, the native bird also can be found on O'ahu in Hamakua Marsh in Kailua, the James Campbell Wildlife Refuge in Kahuku and a refuge in Hale'iwa.

Chuck Johnston, a Mariner's Cove resident whose home overlooks the Rim Island 2, said he wakes every morning to the chirping of thousands of birds.

"Right before daybreak, there are so many different birds there," Johnston said. "It's a natural habitat without any predators."

Reach Suzanne Roig at sroig@honoluluadvertiser.com.