Building 78 homes at Ellwood Mesa would block views, destroy nearly 200 mature eucalyptus trees and significantly disrupt portions of a wintertime monarch butterfly habitat -- but Goleta officials say these don't appear to be "fatal flaws" in the plan.

These and other effects of the Comstock Homes and Development Partners project as currently proposed -- including boosting recreation across the picturesque wildland -- are the focus of a 3-inch-thick environmental review released Tuesday by the city of Goleta. The report is one of a number of key documents being released this week in connection with the complex deal that could create a highly anticipated public open space along the fragile Ellwood-Devereux coastline.

While officials said none of the concerns raised in the environmental review are enough to kill the housing plan, Comstock may need to compensate for damage by timing construction around butterfly migrations, planting new trees, scaling back home layouts or shrinking the overall "footprint" of the project.

"There are a variety of solutions to any issue that is identified," said Ken Curtis, the city of Goleta's planning director. "Those are not fatal flaws. There are many ways of resolving some of the environmental effects."

Developer Bob Comstock said Tuesday that he is open to discussions about layout changes. Without delving into specifics, however, he said he would not want to leave the negotiation table empty handed.

"There is flexibility," Mr. Comstock said. Still, "it's a two-way street."

And, if talks turned sour, "I think we'd just turn around and say, 'Thank you very much,' " he said.

Government officials are asking for public input on the $325,000 study, the second in a series of reports scheduled for publication this week and next in connection with the Ellwood area.

In combination, these reports document the crux of a $3 million effort by Goleta, UCSB and Santa Barbara County to shift proposed homes away from the Ellwood coast and create a permanent open space on the mesa. The reports will help local and state decision-makers carve a future for the vacant space popular among hikers, cyclists, joggers and beachgoers.

The Comstock project -- as currently envisioned -- stems from a land swap announced in 2002 in which the Trust for Public Land would buy a central 137-acre portion of Ellwood Mesa from Comstock for more than $20 million, then give it to Goleta.

The city, in turn, would give Comstock 36 acres of nearby Santa Barbara Shores Park for the homes. The trust so far has raised more than $13 million, and its managers hope to have the rest by year's end.

The deal would help create a 652-acre Ellwood-Devereux Open Space; Goleta, UCSB and the county would each own a portion. On Monday, officials released a draft management plan for the entire area that calls for new trails, parking and conservation.

Environmental impact reports on housing projects proposed for the UCSB- and county-owned portions of the area are due next week.

The Goleta City Council will hold a public hearing on the Comstock plan and related impacts on April 2.

Mr. Comstock on late Tuesday afternoon said he had not yet read the environmental impact report. He did, however, reject a suggestion that some of the proposed single-family homes might work better as townhomes to reduce the overall size of the project.

"We have zero interest in going that route," Mr. Comstock said. "Hopefully, the city will be willing and open about trade-offs."

The project would doom 190 of 450 eucalyptus trees along its northern and western boundary. In addition, several protected raptor species routinely roost and forage at the project site. And several public trails that run through it would be closed.

The project would block existing views of the ocean and Channel Island from Hollister Avenue, and Santa Ynez Mountain views from the mesa.

In considering the project, the Goleta council could make a "statement of overriding considerations" that would, in effect, forgive damage to the environment by recognizing that the project achieves public benefits that outweigh negative effects. Any council endorsement of the project is subject to subsequent Coastal Commission review and approval.

Cecilia Brown, a member of the Goleta Design Review Board, described the loss of views as her biggest concern, and suggested Comstock may have to drop some homes from two stories to one to compensate.

"I don't know how that pencils out," she said. "There are certainly some design issues that the City Council is going to have to take a look at."

At the same time, acknowledging the tightrope that city officials tread, she suggested that some negative effects are acceptable.

"There are some big trade-offs," Ms. Brown said. "That is the key here. the community is getting a great asset, and may have to not have all of its desires met completely in terms of its wish list."