NEAR OREGON CITY, Ore. - Giant and mostly dormant landslides threaten people and homes in many areas of Western Oregon and Washington, but houses are still being built on the slides.

Geologists have known about these slides for decades, but time and again cities and counties have allowed developers to build on them because of often conflicting reports from private engineering firms, and also because state building codes do not restrict construction on what some experts say is dangerous ground.

Just outside of Oregon City, behind the gates of Hidden Lake Estates, the ground is slowly moving on the Street of Dreams, with little hope of stopping it.

Dr. Scott Burns, a Geology Professor at Portland State University, is an expert on landslides and has studied hundreds of them, most recently in Stevenson, Washington where the earth is disappearing below a home.

Back in 1999, Burns also studied a landslide in Kelso, Washington that he says bears a lot of similarities to the slide at Oregon City's Street of Dreams.

"It's exactly the same type of scenario," said Burns.  "We hope that the Street of Dreams, that we can stop it right now and that we will not have the scenario that we had in Kelso."

Rod Moxley lives less than a mile west of the Street of Dreams.  His home started sliding in 1996, along with three of his neighbors' houses. Railroad ties now support his abandoned home, reminders of the nightmares he faced a decade ago.

"It's terrible," he said.  "Nobody should have to go through that." 

After the disaster, Moxley studied the geology of the area and found ancient landslides everywhere.

"The county should have known," he said.

Moxley said the county should have known because a 1979 map shows recent slides near his house and potential slides on Hidden Lake's Street of Dreams.

KATU News went to the county to ask some questions.  "We had Hidden Lake Estates where they show it was in landslide topography and yet these homes were built?" we asked.

"Hidden Lake properties are on a slide, but again, that's why appropriately trained and credentialed professionals do that review and present to us their best information," said Scott Caufield, a Building Code Administrator with Clackamas County.

The problem is that those certified professionals contradict one another in their reports. 

One from 2004 stated it was perfectly safe to build on a site that is now sliding.  A 2006 study identified slides, as did another one from 2001 on an area adjacent to the building site.

Geotechnical engineers used old maps, along with their own research, and found a vast majority of the site lies within areas that are prone to slope failures and commonly involved in large slope failures.

They also examined aerial photographs and stated "slopes exhibit characteristics of deep-seated landsliding."

Caufield said he was not familiar with the report we showed him.  He also said he had not seen precise mapping completed this winter showing nearly every home inside Hidden Lake Estates, including the Street of Dreams, sits on an ancient landslide. It is one of the largest slides in Clackamas County, putting the fate of more than a dozen multi-million dollar homes in question.

If you look closely at the new maps, you can see there is one home that is outside the ancient landslide area.  It is owned by one of the developers, Kent Ziegler.

We tried to reach Ziegler at his home, but did not have any luck.  His partner, Roger Le-Clair Aslo, was not home either, but he did call us back.  However, he hung up after hearing one question.

Did the developers know they were building on an ancient landslide?  If so, they may have missed a major rule for building on slides.

"The thing that they need to do is to remove the water from the slide and stop additional water from getting in," said Burns.

An estimate for work on the Street of Dreams shows developers planned to spend $32,767 on storm water and sewer construction.  They ended up spending $25,247 on the work.

Moxley, whose home started sliding in 1996, installed more than $51,000 in drainage on his home alone to slow the sliding.

Nowhere in any of the development plans or building permits could we find any special drainage or storm water systems on the Street of Dreams, for a landslide-prone area. 

However, according to Caufield, none of that is required.  We asked if the county had employed a certified geologist to look at the plans and Caufield said no.

Instead, the county relied on a Portland engineering firm, which signed off on the builders' plans for the homes involved in the latest landslide on the Street of Dreams.

Homeowners and geologists say the problem is that cities and counties do not have geological experts on staff or even on retainer to approve building plans.