The continued weakening of Tropical Storm Olivia will allow most services on Oahu to operate on a regular schedule today, but city and state officials are keeping their guard up for a possible deluge of rain and strong winds.

As of 8 p.m. Tuesday, Olivia was about 105 miles east of Hana and 230 miles east of Honolulu, with maximum sustained winds of 50 miles per hour and moving west at 8 mph, according to the Central Pacific Hurricane Center. Tropical storm-force winds extend 105 miles from Olivia’s center.

While the five-day forecast showed the “cone of uncertainty” had shifted south and no longer included Oahu, there remained a continued threat for tropical storm-force winds as Olivia approached, according to meteorologists. The City and County of Honolulu warned that sustained winds of 30 mph with gusts of up to 50 mph were possible.

Honolulu Mayor Kirk Caldwell partially activated the city’s Emergency Operations Center as of 6 p.m. Tuesday, with a full activation planned for 6 a.m. today. Full activation means staffing 24 hours a day until a decision is made to deactivate.

Caldwell said the potential for flooding is his biggest concern. City crews have been clearing streams and other waterways since last week, but even multiple pre-storm clearings might not make a difference in some situations, he said.

“They’re saying 5 to 10, maybe 15 inches (of rain),” Caldwell said Tuesday. He noted that about 5 inches was dumped on East Honolulu in April, causing Wailupe Stream to flood and severely damaging a number of homes.

“We just can’t handle a ton of rain that occurs, for example, on the island of Hawaii, so that’s our bigger concern,” Caldwell said.

Ross Sasamura, director of the city Department of Facility Maintenance, said crews from all eight of his district yards have spent the past week clearing out waterways.

“They’ve been out there, but again … mouths get plugged up again and the volume of water — our streams were just not made to handle the type of water we’re seeing nowadays,” Caldwell said. “I think climate change is contributing to it. You saw what happened in Hanalei.

“I mean, they get tons of water, but they couldn’t handle almost 50 inches in a 24-hour period. The entire valley became one giant stream, basically,” he continued. “Those kinds of events could occur here — maybe not to the same degree, but we’re just much drier than Kauai, so half that rain would have devastating impact.”

Sasamura said the Wailupe Stream flooding was the result of heavy localized rainfall coupled with the high tide. “If you already have your stream filled with (ocean) water from the tide, when you have all this other rainwater coming in, the capacity of that stream is not able to handle both things at the same time.”

Caldwell said there are several other options, none of them good or cheap. “You either condemn the homes and widen the stream, which they wouldn’t be happy about, or you can build walls along the stream and control the flow, but you’d still have (Kalanianaole Highway) acting as a dam, so you’d have to raise the highway up higher,” he said.

Emergency Services Director Jim Howe said the high number of severe storms recently has taken its toll on North Shore beaches, and Olivia will only add to the erosion.

From Ehukai Beach to Rocky Point near Sunset Beach, “there’s almost no beach, and we have already seen, just during the summer, erosion to the point where there’s just no beach access. We also are seeing trees and bushes and stairwells collapsing onto the beach,” he said.

The direction of Olivia’s arrival coupled with an afternoon high tide means “it is very likely that we’re going to see some very strong erosive effects up there,” Howe said, adding that people should stay way from cliff areas that could collapse.

SHELTERS OPEN

BIG ISLAND

One evacuation shelter in Hawaii County opened Tuesday evening ahead of Tropical Storm Olivia:

>> Waimea Community Center, 65-1260 Kawaihae Road, Waimea

MAUI

Seven evacuation shelters in Maui County opened Tuesday evening:

>> Lahaina Civic Center, 1840 Honoapiilani Highway, Lahaina

>> Maui High School, 660 Lono Ave., Kahului (pet-friendly)

>> Kihei Elementary School, 250 E. Lipoa St., Kihei (pet-friendly)

>> Kalama Intermediate School, 120 Makani Road, Makawao (pet-friendly)

>> Hana Elementary and High School, 4111 Hana Highway, Hana

>> Molokai High School, 2140 Farrington Ave., Hoolehua

>> Lanai Elementary and High School, 555 Fraser Ave., Lanai City

OAHU

Eight evacuation shelters on Oahu opened Tuesday night:

>> Brigham Young University, 55-220 Kulanui St., Laie (pet-friendly)

>> Ewa Mahiko District Park, 91-1205 Renton Road, Ewa Beach (pet-friendly)

>> Kailua District Park, 21 S. Kainalu Drive, Kailua (pet-friendly)

>> Kalihi Valley District Park, 1911 Kamehameha IV Road, Honolulu (pet-friendly)

>> Kaneohe District Park, 45-660 Keaahala Road, Kaneohe

>> Manoa Valley District Park, 2721 Kaaipu Ave., Honolulu

>> Wahiawa District Park, 1129 Kilani Ave., Wahiawa

>> Waianae District Park, 85-601 Farrington Highway, Waianae

Officials urged the public to shelter in place or stay with friends and family outside of hazard areas if possible. Those who do opt to go to an evacuation shelter should bring food, water, bedding and emergency supplies. Those bringing pets to pet-friendly shelters should bring pet carriers or cages as well as food and water for their pets.