A developer plans to spend more than $7 million to build nine big T-shaped breakwaters off Iroquois Point beach to protect a rental community, stop erosion and replenish sand fronting former Navy housing near the mouth of Pearl Harbor.

Ford Island Housing, which has 1,450 rental units at the Waterfront at Puuloa, also would clean up shoreline debris from past efforts to stem erosion.

According to a Navy environmental assessment for the project, a contractor will build nine "T-head groin structures" made of rock and filled with sand along 4,200 feet of shoreline.

The groin structures will have stems (perpendicular to shore) 140 feet long and heads (parallel to shore) 100 to 200 feet long.

Jill Bona, a company representative, said "a few feet" of rock groin will be visible during low tide.

The project is expected to start this summer and take about 10 to 12 months, officials said. The site is bordered on all sides by military reservation land, and the offshore waters are part of a naval defense area.

In 2003, under special legislation by Congress as part of a Ford Island master development plan, the Iroquois Point housing was leased by the Navy to Hunt Cos., based in El Paso, Texas.

The lease originally was 65 years but was extended to 99 years, according to the environmental assessment.

The former Navy housing, which is now rented to civilians and the military, was built in 1960 and renovated extensively by Ford Island Housing, but the beach problems remained.

"Chronic erosion and shoreline recession, coupled with backshore flooding due to wave overtopping of the low-lying shore, have resulted in the abandonment of 16 shoreline homes to date," the environmental assessment said.

Old aerial photographs and other information revealed that the beach in the project area receded as much as 130 feet between 1928 and 1961, and an additional 150 feet between 1961 and 2003, according to the report.

More homes are threatened by shoreline erosion, and emergency shore protection for those homes was put in place in 2004 — one of the many efforts attempted over the years to keep tidal action at bay, the Navy report said.

As part of the beach stabilization, 80,000 cubic yards of sand would be placed in the groins. In 2007 the Navy performed maintenance dredging in the Pearl Harbor channel entrance next to the Iroquois Point housing and stockpiled 22,000 cubic yards of sand that could be used for the upcoming beach stabilization, the assessment said.

An additional 60,000 cubic yards would be dredged from the west side of the entrance channel using a drag line, loaded into trucks and stockpiled for transport to Iroquois Point beach. The sand "would be pushed seaward from shore, with no equipment working in the water," the report said.

By comparison, the Waikiki sand replenishment now under way for $2.3 million is adding 24,000 cubic yards of sand — less than a third of that planned at Iroquois Point.

George Downing, president of the environmental group Save Our Surf, which fought against plans for rock groins off Waikiki, said he was unaware of the Iroquois Point beach stabilization plan.

"I’ve got to see what they are doing before I could make any statement on the thing," Downing said.

Steve Colon, president of the Hawaii division of the Hunt Development Group, said the Navy informed the developer back in 2003 when a lease was signed "that there was chronic beach erosion that we should be aware of and that it was a significant dollar amount to fix."

"It’s an ambitious project, a complex project because of the size and the amount of shoreline involved. So I think it was just something that we’ve taken several years to get this far," Colon said of the planning for the beach stabilization.

The eroded sand has been transported to the east and into the Pearl Harbor entrance channel, resulting in the need by the Navy to conduct dredging.

A historical shoreline analysis showed that as sand eroded near Keahi Point, it accumulated in the channel near the mouth of Iroquois Lagoon, adding 125 feet to the vegetation line and engulfing previously used docks and a channel marker, the environmental report said.

Various efforts utilizing rocks, a sand berm, concrete masonry, a wooden wall, timber piles, concrete blocks and a retaining wall were attempted — unsuccessfully — in 1978, 1984, 1985, 1986, 1993, 1995, 2004 and 2009.

Eroded earthen fill now creates a plume of dirt in the water, and concrete sewer lines abandoned in the 1980s lie broken and exposed on the beach, according to the environmental report.

"One of the huge benefits, to me, to getting this project approved is it’s going to allow us to clean up the beach," Colon said.

The report said incoming waves break with no consistent pattern, and there is surfing, but no named surfing sites are located within the project area.

The National Marine Fisheries Service said the proposed beach stabilization project is not likely to adversely affect the Hawaiian monk seal, the hawksbill sea turtle or the green sea turtle.

The Navy report added that the constructed groins are likely to result "in a greater diversity and biomass of fishes and crustaceans, which may provide nearshore forage resources for monk seals."

The surface area created by the structures and sand would amount to 4.6 acres. The cost estimate in the report for the work is $7.3 million. Colon said while the project is under way, residents and visitors will still be able to use the beach.

As part of an $84 million deal with the Navy, Hunt and its Ford Island Properties received land and housing on Oahu (including the Iroquois Point property) in exchange for infrastructure and other improvements on Ford Island.

Hunt has been trying to sell the Ewa Beach subdivision. Local developer Peter Savio said in October that a group he put together successfully bid between $300 million and $350 million for the community, and that he planned to sell the homes.

But Bona, the Hunt representative, said Friday that negotiations and a formal letter of intent were not successful, and that Hunt is considering other bids that were presented.

Bona said a potential sale won’t affect the beach stabilization, and that Hunt is responsible for paying for it.