MARTINEZ (KCBS) – A large portion of property owners in Contra Costa County remain underwater, making payments on mortgages higher than the value of the home, even though overall home prices in the San Francisco Bay Area are climbing upward once again.

During the final three months of 2012, one in three homeowners in Contra Costa had negative equity in their properties, according to data published by the listing site Zillow.

READ MORE: Santa Clara Shoe Store Ransacked in Late Night Smash-and-Grab Robbery

“It’s very neighborhood specific,” said realtor Jim Walberg of Keller Williams Realty.

KCBS’ Rob McAllister Reports:

READ MORE: COVID Omicron: Rush To Vaccinate In East Bay As New Variant Emerges

Underwater mortgages and short sales where the homeowner sells at a loss were especially common in east Contra Costa, Walberg said, while the area surrounding Interstate 680 has been thriving.

“From Orinda down to San Ramon, that particular corridor probably never has been healthier in the last seven years,” said Walberg.

The uneven situation in Contra Costa County contrasts with that in coastal cities such as San Francisco, which – with one in ten underwater mortgages – had the fewest negative equity properties.

MORE NEWS: Lee Elder, 1st Black Golfer To Play Masters, Dies At Age 87

(Copyright 2013 by CBS San Francisco. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)