Mixed Reviews for Bolsa Chica Plan : Wetlands: Report says proposal to build houses around state preserve would increase air pollution but lead to the restoration of marshes.

Proposed residential development of land ringing the Bolsa Chica State Ecological Reserve would increase air pollution but also aid wetlands restoration, according to a massive study released Friday.

The environmental impact report assesses the proposed development by the Koll Co. of up to 4,884 housing units. On the positive side, the report said the “proposed plan would create full tidal salt marsh restoration” of some degraded wetlands. But the report also said that “residential development would change the character of a large portion of the site.”

Both critics and proponents of the proposed development found support for their arguments in the report, which was prepared by Chambers Group Inc., a private organization.

“I’m very encouraged about what it has to say,” said Lucy Dunn, a Koll senior vice president.

By contrast, Ralph Bauer, an official of a Huntington Beach group opposing the size of the development, said the environmental report “talks about the air pollution problem that will be created. You can’t get around the fact that there’s going to be more traffic and air pollution.”

Bauer, a spokesman for the Consortium of Organizations Planning for Bolsa Chica, said his organization wants to reduce the number of houses in the project by about three-fourths.

At issue are 1,200 acres near Warner Avenue and Pacific Coast Highway. The undeveloped land fans around the 300-acre Bolsa Chica, which is the largest active wetlands in Southern California.

An agreement in 1988 among state, county and city governments and the conservation group Amigos de Bolsa Chica calls for allowing some residential development around the Bolsa Chica wetlands. In exchange, the proposed developer would donate land and money to help restore more wetlands.

The report said it would be “environmentally superior” to restore the wetlands and use part of the land as a park. But it also concluded that “the feasibility of this alternative is questionable” because of funding.

Most of the report was devoted to analyzing what would happen to the land if it is developed by the Koll Co. as proposed.

Some of the negative findings included an anticipated worsening of air pollution, the need to provide more water to the development than the city had planned, and the spoiling of scenic views along Bolsa Chica State Beach and Pacific Coast Highway.

In addition, the development will force burrowing owls and the California horned lark from land near the wetlands.

Among the positive findings were the restoration of some wetlands, the buildup of sand on the shore because of site alteration and the donation of some privately owned land for public use.

The public will be invited to comment on the report during the next three months. Then the City Council will debate and vote on the findings.