Sinkhole caves in median and stretches under road along Artesia Boulevard
Crews from Manhattan Beach and Redondo Beach assess the erosion under the sinkhole. Photo
A sinkhole, at least eight feet deep and stretching north, more than 22 feet below the pavement, closed Artesia Boulevard in front of Mira Costa High School Thursday afternoon. City staff from both Redondo Beach and Manhattan Beach expect the street to be closed to traffic for at least 24 hours.
“I’m hoping its done within three days,” said Manhattan Beach Public Works Director Stephanie Katsouleas. “I would say, based on what we have to do, we’re looking at least two days and possibly through the weekend.”
The sinkhole appeared in the median of Artesia Boulevard between Goodman Avenue and Peck/Ford Avenue shortly after 3 p.m. Roads were closed in both directions shortly thereafter.
The sinkhole appears to be at least eight feet deep, and stretches at least 20 feet north and south of the median. Submitted photo
“There is void space under the pavement,” Katsouleas said. “Looking north, the hole goes at least a lane, lane and a half — about 12 feet back under the pavement,” and approximately 10 feet under the road on the south part of the street.
The hole, estimated to be eight to 10 feet deep, is located in the center of the street, at the lowest point of the block. It opened over a pipe that drains water from Manhattan Beach and Redondo Beach catch basins into the Wylie Sump stormwater basin, to the south of Mira Costa High.
The bottom of that corrugated metal pipe, which connects the catch basins to the sump, appears in photos taken by city crews to have rusted away. Water leaking from the pipe appears to have eroded the surrounding soil, according to Redondo Beach Public Works Director Ted Semaan.
“Those used to be used regularly in decades past — they’re metallic, and rust because of the water. You can see it in communities that have had them since the ‘40s or ‘50s,” Semaan said. “Over the years, it’ll give.” It’s not clear how old this particular pipe is, though crews on the scene identified that it had been in city plans since before 1968.
Katsouleas said they’ll know more after contractors determine the extent of the work needed.
“We’re glad it was a soft spot in the median where it showed up, before the weight of a vehicle compromised the asphalt,” Semaan said.
Crews work Friday morning to fill a sinkhole on 35th Street in Hermosa Beach. Photo
Sinkhole closes Hermosa Beach street
In Hermosa Beach, 35th Street was closed between Hermosa Avenue and Manhattan Avenue after a 15-foot-square sinkhole was discovered in the eastbound lane early Thursday morning. City workers covered the hole with a tarp. They did not say when the street will be reopened.