Lake County officials are countersuing a group of landowners who blame the county for a landslide that damaged or devalued their homes last year.

The county’s lawsuit contends the homeowners and their Lakeside Heights Homeowners Association caused the damage by failing to maintain their landscaping, vegetation and irrigation system.

“They had significant leaks in their irrigation lines, which are owned and controlled by the plaintiffs and the homeowners association,” said Adam Abel, an attorney with the Larkspur legal group handling the lawsuit for the county. The lawsuit was served on the homeowners late last month.

Abel also said the homes that suffered damage were built on inadequately engineered fill in an area that at some time in the past had been subject to a landslide. Abel said that landslide could have been as much as 100 years ago, or even more. For some reason, the slide was not noted in a 1979 soils report upon which authorization of the subdivision was based, he said.

The homeowners’ lawsuit, filed last year, claims that leaks in the county’s water system caused the land beneath 17 hillside homes to give way. Other homes in the 29-residence Lakeport-area subdivision have been devalued because no one wants to live there, according to the lawsuit.

The lawsuit also notes the county was responsible for overseeing the planning, design and construction of the subdivision.

Neither lawsuit names an amount of damages being sought.

Homeowner Randall Fitzgerald said the county’s countersuit is a low blow.

“For Lake County government to pull this cynical and desperate legal tactic, suing hard-working taxpayers who face financial ruin because their homes have been destroyed, is a new monument to the old saying, ‘adding insult to injury,’ ” he said.

The homeowners have said their lawsuit is their only means to recover their losses. Insurance policies typically do not cover damage caused by shifting soil, called “subsidence.”