SAN DIEGO COUNTY, Calif. — The heavy rain that hit San Diego last week not only broke records, but it also caused some hillsides in Solana Beach to give way along Santa Rosita Drive.
Geology professor Dr. Pat Abbott said there are multiple reasons for the collapse in an area that has history of failure.
"This is not a new story for Santa Rosita Drive. You look at the barren slope with the sediment washing out on the street. You see loose sand and mud. In other words, very weak sedimentary rock" said Abbott.
Excavation work on the slopes for nearby homes also played a role.
"They came in and on a slope like this, cut a steep slope on weak rock and then gravity does the rest," said Dr. Abbott.
To make things worse, the recent heavy rains.
"Nine straight days of rain. I'm not concerned about how many inches fell. It's the fact that day after day, means it gets to soak, soak, and soak deeper and deeper into the ground," said Dr. Abbott.
Irrigation also could have played a role.
"If they're still running the irrigation schedule and then add several inches of rain over nine days on top of that, they are lucky they haven't had more of the slopes fail," said Dr. Abbott.
News 8 reached out the city of Solana Beach, and they responded with an email:
"The landslides are primarily due to excessive rain saturating steep slopes in a number of locations throughout the Santa Fe Hills community. These slopes are all located on private properties and the City does not have any authority nor responsibility to enter these properties. The City has inspected the impacted areas and has determined that structures (homes) and public safety are not at risk. The City will work with the property owners and/or the HOA to assist in developing repair plans and to obtain required permits for the repair work."
Dr. Abbott said he would like to see a different landscape.
"I would much rather prefer to use something that is a more natural plant. Tie it down with things that you're not adding irrigation water to," he said.
In other words, native plants that are drought tolerant. For now, homeowners will have to keep an eye on the next rain system that moves into the area.