A 285-lot residential subdivision on Ridgeway Butte was approved by the Lebanon Planning Commission on July 9. The vote was 7 to 2.

The development plan calls for mostly large single-family lots on 314 acres of the hill across the South Santiam River from Lebanon. Portions of the property will be set aside for a park and trails. As many trees as possible will remain on the hillside to protect views from the development and of the butte from the city.

A five-acre park near the top of the butte and trails will be transferred to city ownership.

About 175 home sites are planned for three "relatively gently sloped areas of land" on the west side of the butte, with another 107 lots on the east side, according to the subdivision application. The buildable area of each lot will be restricted to a small portion of the overall lot, according to a statement from Ridgeway Butte LLC after the hearing.

Development is expected to take place in 12 phases over 10 years, with work on the first phase beginning in spring 2009 near East Grant Street on the west side of the butte.

Lots will range from 8,700 square feet to 33 acres, with an average size of a little more than an acre.

The development will have one public access point off East Grant Street. An emergency access road will be built to Golden Valley Drive on the east side of the butte after 30 homes are constructed.

Streets will be located to avoid deep cuts into the ground and grades will be minimal where possible, with only one 200-foot length of road with as much as 15 percent grade, said Andrew Tull of HRG Design of Portland.

Due to concerns over fire safety on the wooded hillside, homeowners will be required to create a defensible space by thinning out dangerous vegetation near homes and using construction materials allowed in the fire code, Tull said. Homes will have sprinklers.

The property has been within the city limits since about 1980, when the city's comprehensive plan was written.

The property rises from 340 feet near Berlin Road to about 1,200 feet at its highest point on the southeast corner of the development area. It includes two former rock quarries and several old logging roads. The western side is steeper than the eastern side.

Much of the discussion centered on the area's steep slopes, possible slide hazards and storm water drainage.

Tim Blackwood, a geotechnical engineer with Pacific Geotechnical, said his company did nine borings and reviewed photos and surveys of the land going back to the 1930s, then walked the ground.

No homes may be built on slopes over 30 percent and the relative few on slopes of 15 percent or greater will require a geotechnical study for the lot.

Conditions of approval included that no more homes may be built than the number in the plan because the infrastructure is designed only for that many.

Robert Biggs, who owns land at the northeast corner of the property suggested the park should be larger and questioned whether the plan includes adequate storm water controls.

"It's just as bad to take away my water as to add more," he said.

His biggest concern is the risk of landslides. He has both a historic slide area and a current slide on his property, he said.

In response, Tull said the developer would be willing to evaluate Biggs' land for slide and drainage issues.

Allen Merrill, speaking on behalf of his son, who owns an 80-acre tree farm adjacent to the development on the northeast, expressed concern about fire safety and surface drainage. Surface and spring water from the development property feeds ponds on the tree farm, he said.

Developer Rick Ely replied that most groundwater will infiltrate into the soil because most lots are much larger than the buildable area.

Mark Tunstill, manager of Mallard Creek Golf Course, said the development is a "great opportunity for the community." Karen Dierksen and Nancy Kirks of Build Lebanon Trails said the group is very supportive of the plan and want multi-use trails to go all the way to the top of the butte.

Planning commissioner Don Robertson questioned whether all lots are buildable, given that some may need additional geotechnical studies.

City planner Walt Wendolowski said any substantial changes in the development plan would require the developer to bring the subdivision plan back to the planning commission.

The subdivision approval may be appealed to the city council.