Wai'anae Coast residents who thought the worst was over following last week's rain and wind storms, power outages and road closures were in for an unpleasant surprise starting at 7:30 yesterday morning during rush hour.

A 24-inch water main break near the off-ramp at Ko Olina Resort again halted traffic on Farrington Highway in both directions. And since the four-lane highway is the only way in or out, once more the Wai'anae Coast was virtually stranded.

This time, at least, the inconvenience didn't last two days, as it had last week. By 9:55 a.m. Board of Water Supply crews and the Honolulu Police Department had opened three of the highway's lanes — two Honolulu-bound lanes and one Wai'anae-bound lane.

The process was reversed during the busy afternoon return commute. At 2:15 p.m., authorities reversed the contraflow, opening two Wai'anae-bound lanes and leaving a single lane for town-bound traffic.

But by that time, residents such as Glenna Hoffman, who lives at the Makaha Valley Towers, had already run out of patience.

"It is the same old, same old out here," said Hoffman, who got caught in last week's traffic mess and chose to stay off the roads altogether yesterday. "It's very discouraging."

BWS spokeswoman Su Shin said the broken pipe is concrete-encrusted and buried deeper than usual, which could add to the repair time. However, she said crews would work through the night to fix the broken main by this morning.

"The good news is that even if they're not done and the workers are still out there, we'll have the contraflow set up in advance and ready for rush-hour traffic," said Shin. "What we can say is that two lanes of traffic will be headed into town during rush hour — whether there will be a contraflow, or whether they'll be finished and off the road."

Shin said weak spots in aging water pipes caused main breaks in the same area recently. Last month, a main break near the Ko Olina off-ramp caused traffic problems on Farrington.

Shin said the long-term solution to the problem will be a 15-month water main replacement project set to begin from Old Farrington Highway to Ko Olina's Ali'inui Drive in early 2008.

"Once that project is completed, that section of pipes will be brand new — meaning you're not going to have main breaks along that stretch for at least several decades."

Meantime, BWS is asking residents from Nanakuli to Wai'anae to conserve water until the current main repair is completed.

Reach Will Hoover at whoover@honoluluadvertiser.com.