To prevent the remainder of Pleasanton's pristine ridgelines and hillsides from being graded into mega-mansions, two residents have filed an initiative to protect the city's surrounding scenic hills.

Former City Councilwoman Kay Ayala and fellow resident Karla Brown submitted the "Save Pleasanton's Hills & Housing Cap" initiative late Tuesday afternoon.

"The people of Pleasanton want to know that, into perpetuity, their hillsides are going to be protected," Ayala said.

Ayala noted that the initiative does not directly address the Oak Grove project -- the 51 custom-home subdivision recently approved by the City Council in Pleasanton's southeast hills -- but she said the initiative would have prevented that project from moving forward.

"This would protect the hillsides from projects such as Oak Grove," Ayala said.

Ayala and Brown said they have heard talk of putting the council's Oak Grove approval up to a public referendum.

As far as Ayala is concerned, the proposed initiative is simply finishing what the city started more than 10 years ago, when its 1996 general plan was adopted.

One of the general plan's goals is to "develop a ridgeline preservation ordinance and scenic hillside design guidelines to improve the safety and reduce the potential negative visual impacts of development in hilly areas."

Ayala, who sat on the council from 1996 to 2004, said she takes partial blame for not developing a ridgeline ordinance, adding that the council was not faced with any hillside developments during her tenure.

Mayor Jennifer Hosterman doesn't see any negative impacts from the proposed initiative, but she said she doesn't see the need for it.

"We have a great number of protections already in place and, in addition to that, we have this slow-growth council that has been particularly focused on balancing the needs of developers with smart environmentally sensitive growth, which, in turn, has yielded a great deal of open space for the people of Pleasanton," Hosterman said. "The initiative is redundant."

However, at the same meeting at which a council majority approved the Oak Grove project, Vice Mayor Cindy McGovern -- who cast the sole dissenting vote -- suggested the council consider establishing a hillside ordinance.

"We have a general plan in place that we thought protected the ridgelines, and with Oak Grove's approval, it obviously does not," said Brown, co-author of the initiative.

If Ayala and Brown can gather at least 3,500 signatures within six months, the initiative will be put to the voters. If passed, housing units or grading would not be allowed on slopes of 25 percent or greater, or within 100 vertical feet of a ridgeline.

The initiative exempts housing developments of 10 or fewer units.

The proposed initiative also would better define a "housing unit" under the city's self-imposed 29,000-unit housing cap.

"Some people are beginning to feel like the housing cap can be loopholed," Ayala said, noting that the city has discussed exempting certain types of housing from the about 1,200 units remaining.

This initiative is the second attempt by Pleasanton to protect its ridgelines. In 1993, voters approved Measure F, or the Pleasanton Ridgelands Ordinance, which restricts development on the west ridge lands.

"Our goal is to take the ridgeline protection they have established on the west and extend it throughout Pleasanton," Brown said.

The beauty of the East Bay often is credited to the hillsides that crown many of its communities, some of which have enacted ordinances to protect their ridges from development. In 2002, Lafayette adopted hillside-development regulations, increasing the number of protected ridgelines, the setback and scope of reviews.

In June, Moraga voters will be asked to support the Moraga Open Space Ordinance 2008, which would strengthen the existing ordinance and extend protection to more than 2,000 acres.

In Danville, voters approved a Scenic Hillside/Ridgeline Preservation ordinance in 2002, which strengthened an ordinance previously adopted in 1984. San Ramon voters adopted the Save Our Hills ordinance in 1990, and in East County, Pittsburg is working on developing a hillside ordinance.

Meera Pal covers Pleasanton. Reach her at 925-847-2120 or mpal@bayareanewsgroup.com.

Hillsides initiative

For more information on Save Pleasanton's Hills & Housing Cap Initiative, visit http://www.savepleasantonhills.com.