Crews were back on Round Top Drive on Tantalus last night to deal with the third landslide there in two days. Rainy weather also caused hundreds of gallons of raw sewage to pour into Lake Wilson.

The spill of 700 gallons of untreated sewage from the Wahiawa Wastewater Treatment Plant into Lake Wilson was attributed to heavy rains from 11:50 p.m. Wednesday night to 12:20 a.m. yesterday, according to the Department of Environmental Services.

The public is being advised to avoid the lake waters as well as those of Lower Kaukonahua Stream, which flows from Lake Wilson, until the state Health Department deems the waters safe again.

Two more landslides yesterday — one during the day and another last night — on Round Top Drive, also caused by brief, heavy rains, frustrated some drivers using the road.

"This is pretty much a repeat performance of what happened on Round Top the day before," city spokesman Bill Brennan said of the second landslide in the area in as many days. "Same place. Same dirt."

Only more of it, said Larry Leopardi, the city's chief of road maintenance. Leopardi said the mud and debris that spilled across Round Top Drive on Wednesday filled about 23 dump trucks. Yesterday's daytime haul filled 28 dump trucks.

"We probably had about 300 cubic yards on Wednesday," said Leopardi. Yesterday, it was around 380 cubic yards.

The city will foot the bill, according to Brennan, even though the landslide came from conservation land owned by the state Department of Land and Natural Resources.

"It would be helpful if the state could come in and shore up that area so this doesn't keep happening and being an inconvenience to the public," he said.

Each landslide shut down the road for about six hours. Leopardi said that other than closing the road, neither slide harmed anyone or caused home or property damage.

The tons of mud slid across the road in a section well away from homes, he explained.

The main problem seemed to be the restricted access to Round Top during the hours the road was closed, and heavy equipment cleared a swath of muck about 3 1/2 feet high and 40 feet wide.

Motorists generally took the inconvenience in stride, although for some, it meant a meandering, 80-minute round-trip detour around Tantalus Drive to reach Round Top and get back out again.

David Willette, lead adjuster for Leakmaster Roofing and Waterproofing, said a Round Top estimate that would otherwise have required a half-hour's work ended up taking more than 1 1/2 hours.

"Normally, I'd have just come straight up Round Top Drive, and the work would have been done in 15 or 20 minutes," said Willette. "But this time, I had to drive all the way around Tantalus to get to the Round Top residence."

Gordon Hung, a mail carrier, was having similar difficulty completing his appointed rounds.

"Usually, I go up Round Top and come down Tantalus," said Hung. "But today, I got as far as I could on Round Top, and then (had to) turn around and come all the way around Tantalus before I could continue. That's because all the mail is sorted in order."

Leopardi said he couldn't say whether the landslides would continue in the same area if the rains persist.

"The word I got from my field guys was that it looks pretty stable right now," he said. "But anything can change, depending on how much water comes down. We think so much came down that there's not a whole heck of a lot left up there. It looks like we're into harder material now."

Reach Will Hoover at whoover@honoluluadvertiser.com.