It's been nearly a month since the city of Rancho Palos Verdes started drilling bore holes as part of a long-term effort to slow the Portuguese Bend landslide, which has accelerated in recent years and is threatening a number of neighborhoods in the area.

So far, four out of the 20 exploratory boreholes have been completed at both the top of the slide and along Palos Verdes Drive South, offering insight into what's going on beneath the surface. Experts are analyzing soil conditions and trying to locate the pockets of water they believe are making the slide worse.

The idea is that water's been getting trapped by layers of thick and sticky clay, adding weight to the hillsides. Once they locate the water, they'll start to pump it out with hydraugers — the hope being that as the weight is relieved, the slide will slow.