Rejecting attempts to substantially weaken or strengthen Howard County Executive Elizabeth Bobo's proposed 1990 General Plan, the County Council has signaled that it will not stray far from the middle path Bobo is steering with her modest blueprint for controlling growth.

Bobo's version of the General Plan, a non-binding guideline intended to direct future rezoning and development, has drawn fire from community activists who think it would allow too much development and mild rebukes from some builders and developers, who say it would be too restrictive.

As it continued its work on the General Plan Tuesday, the council tentatively agreed to an amendment that would increase the percentage of moderate-income housing required of builders.

As proposed by member C. Vernon Gray (D-District 3), the amendment would require builders of projects of more than 25 detached houses, town houses or condominium apartments to set aside 10 percent of the units for moderate-income people. The Bobo plan calls for a 5 percent set-aside. The amendment would not increase Bobo's 10 percent set-aside for low-income people. (The county does not now require that builders accommodate low- and moderate-income people.)

Under Gray's amendment, the units would be donated to the county or a nonprofit housing agency; the builder could elect instead to make a cash payment to the county housing fund. Gray said his amendment might increase the number of donated units by 50 a year.

Last week, in the council's first work session on the 10-year plan, several proposals for toughening it failed or had so little support they never reached the table.

Council member Angela Beltram (D-District 2), for instance, could not muster the eleventh-hour support she needed for proposals to lower the density Bobo's plan would permit for development on the western side of the county.

"I'm not even going to introduce them," Beltram said, pointing to a stack of amendments on the floor that called for 10-acre, 15-acre or 20-acre lots.

Bobo's plan calls for clustered housing at an overall density of one house per five acres, with the rest of the land left for open space or agriculture. Currently, the county's rural west is zoned primarily for three-acre lots.

Beltram did find unanimous support for an amendment calling on the county's Department of Planning and Zoning to study directing development in the western part of county into existing communities to preserve farmland and open space.

"There would be much less sprawl" than with Bobo's existing plan, Beltram said.

Beltram's proposal would concentrate development in a half-dozen existing small town centers, such as Clarksville, Lisbon, West Friendship and Cooksville.

"We have been disappointed to see no analysis of that option by Planning and Zoning so far," said Joyce Kelly, president of the Howard County Citizens' Association.

Beltram also sought council support for a move to eliminate the designation in the plan for a "mixed-use center" at an 800-acre farm near Routes 29 and 216. The council rejected Beltram's argument that the large rural tract is not appropriate for development as a combined commercial-residential center.

"It's a nice place for a farm, a wonderful place for a farm. It's hard for me to do this, but we've got to look to the future," said Council Chairman Shane Pendergrass (D-District 1), who voted to maintain the mixed-use designation.

Beltram was not the only council member to fail in efforts to significantly change the plan. The council voted 3 to 2 against a proposal by Gray to change Bobo's proposed "greenbelt" west of Columbia.

Gray's proposal "confuses the situation and guts the concept" of a greenbelt, said County Planning and Zoning director Uri P. Avin.

Gray's amendment would have turned the "greenbelt" into a "greenway" designed to protect the Middle Patuxent and Patuxent rivers. Gray said his plan would better protect the rural quality of the area.Staff writer Claudia Levy contributed to this report.