The Petaluma Planning Commission on Tuesday roundly criticized the draft environmental impact report for a large housing subdivision proposed for the western outskirts of town, with one member calling it "completely confusing."

Commissioner Dennis Elias went a step further: "The draft EIR is immensely inadequate."

At issue is the Davidon Homes proposal for as many as 93 houses on 60 acres at Windsor and D Streets, adjacent to Helen Putnam Regional Park. The subdivision is the largest housing project planned for Petaluma in about the past five years, when the controversial 274-home Quarry Heights hillside project was in the works.

In a 4 1/2 hour hearing, the commission took comments from about 30 members of the public on the report – virtually all of whom raised concerns – and agreed on several topics commissioners felt needed to be reevaluated in the final EIR.

Several commissioners said the number of scenarios with varying numbers of homes in different configurations made the report unclear.

"It's completely confusing," said chair Jennifer Pierre. "This is the most difficult EIR I've read in my life."

"I can't even make a recommendation on this because I'm not even sure what I'm recommending," said Commissioner Ray Johnson.

The report included the original proposal for 93 homes that Davidon proposed in 2004. The project stalled for several reasons after it began the EIR process then.

In the meantime, issues involving the federally threatened California red-legged frog surfaced and the city rewrote its general plan and revised its zoning codes, which guide development throughout the city.

Davidon then proposed its own scaled-down alternative option of 66 homes, which also was included in the draft EIR, along with those with 48 and 28 homes. Removing lots to protect the frog or preserve scenic views would reduce the numbers further.

Because the project application was deemed complete in 2004, it is subject to the general plan that was in effect before the city rewrote it in 2008.

Petalumans for Responsible Planning has been coordinating opposition to the project, as it did in the mid-2000s. Many of the speakers raising concerns about the project live in the nearby Victoria Homes subdivision who for decades have enjoyed the park-like open space and Kelly Creek as if it were their backyards.

They argue the former Scott Ranch farmland is too scenic to be heavily developed and such a project – particularly south of Kelly Creek – would bring unwelcome noise, traffic, greenhouse gas emissions, and environmental and habitat damage. They also want to protect an old barn along the creek.

They also suspect Davidon seeks an easier track to approval by being judged by the old general plan instead of the newer one, which tightens development requirements.

Davidon Vice President Jeff Thayer and attorney Marie Cooper spoke briefly toward the end of the hearing, explaining the timeline and describing how they attempted to solve some of the environmental impacts before the draft EIR was done.

"It's taken nine years to get an EIR," Cooper said. "We're not starting over."

She said the project complies with both the newer general plan and the older one.

The commission recommended the final report contain additional evaluation on lots planned on slopes or the ridgeline, traffic, tree preservation, and greater study into flooding, runoff and erosion issues on the hilly site.

The city council will also consider the draft EIR, possibly next month.

The final EIR with responses to comments could be completed late this year, followed by a second review and ultimately a council vote on its adequacy, which determines whether a project can move forward.