The New Year's Eve Flood on Oahu, Hawaii: December 31, 1987 - January 1, 1988 (1991)

Lifelines include power (energy), water, sewerage, transportation, and communication systems. Most interruption of lifelines was minor and short lived, with the exception of Kahena Street in Hahaione Valley, which is discussed separately in this chapter. Although most of the disruptions were minor, an assessment of them is presented below because of the crucial function they perform in effective emergency response and community recovery efforts.

Eastern Oahu comprises narrow coastal valleys surrounding the southern portion of the Koolau Mountains. The only artery linking eastern Oahu with the rest of the island is Kalanianaole Highway, which completely circuits the southern Koolau Mountains.

At about 7:15 p.m. on New Year's Eve, Kalanianaole Highway was flooded at Waimanalo near the gate of Bellows Air Force Base. Four-wheel drive vehicles with elevated chassis could operate, but the road was closed to other vehicles. At about 10:00 p.m. the highway was closed by debris flows at Niu and Kuliouou valleys. It remained closed until late in the afternoon on January 1.

The communities of eastern Oahu were essentially isolated by the road closures. The principal consequence was inconvenience to the many people who were unable to return home from New Year's Eve functions. Several diabetics faced a shortage of insulin but were able to find a source at a clinic in Hawaii Kai.

A minor disruption occurred on the Pali Highway, which is one of two arteries transversing the Koolau Mountains, connecting Honolulu and the windward communities of Kailua and Kaneohe. Landslides and waterfalls temporarily blocked the tunnels where the highway cuts through the Koolau crest. A few cars were trapped in the tunnels by debris. Most traffic was diverted to the adjacent like Highway.

Transportation and public works officials faced major problems with mud and debris removal efforts. The need for heavy equipment and personnel to clean the roadways (especially Kalanianaole Highway), flood control channels, and culverts quickly overwhelmed available public resources, which included city and county road crews, the Hawaii Department of Transportation, and the National Guard. However, on January 3 Honolulu County's Public Works Department was able to implement ''Operation Bulldozer," an emergency response plan that, through prearrangements with private contractors, provided dump trucks and earth-moving equipment to assist in the cleanup activities, which continued for several days.

Although Bellows Air Force Base once had active air traffic, no general aviation facility now exists in eastern Oahu. The only air access is by helicopter. Helicopters were used during the emergency for damage surveillance beginning on New Year's Day.

Electric power outages resulted from the high winds that occurred during the latter stages of the storm. The outages occurred primarily when trees were blown against power lines on the leeward slopes of the Koolau Mountains. This type of outage generally occurred in regions removed from the actual flood zones. In addition, a Hawaiian electric substation at Waimanalo was flooded by waist-high water, causing a 1-hour outage for 1,300 customers. Utility companies worked throughout the night to restore service to customers. Although there was no major disruption of electricity service, residents of the flooded areas, such as in Coconut Grove, Niu, and Waimanalo, could not use electrical power because outlets and appliance motors were wet. Also, reduced capacity continued at the Waimanalo substation for several days following the flood.

Telephone service was badly disrupted, with outages primarily due to water damage to underground circuits. Approximately 3,000 customers were affected. These customers were in addition to the 4,000 who had lost phone service during the earlier December rains. Most outages were remedied within a few days. The 911 emergency number was saturated with calls for assistance and information. Officials requested that the public reserve 911 for true emergencies. The Oahu Civil Defense Agency and Red Cross served as information and referral sources to alleviate the strain on the 911 service.

Much of eastern Oahu has cable television. The cable connections typically use telephone conduits and thus suffered the same water problems as telephone service.

Cable service for Hawaii Kai (MaCaw) was restored within a few days to all subscribers except those on Kahena Street.

The water supply source for the upper reaches of several Oahu valleys is surface water. The Honolulu Board of Water Supply found evidence of some contamination in the local supplies and suggested that residents in Kalihi and Nuuanu valleys boil water. Residents of Upper Hahaione Valley were also advised to boil water due to possible contamination from ruptured water lines. The advisory was in effect for 1 week.

Flooding caused sewage spills at six wastewater treatment plants from Waimanalo to Ahuimanu, sending 41 million gallons of only partially treated sewage into streams and the ocean. Public health officials posted contamination warning signs on beaches and in other public-use areas bordering Kaneohe Bay. Relief workers and victims in the flooded areas were advised about precautionary sanitation measures. No major health problems were subsequently identified.

Kahena Street, in upper Hahaione Valley, is part of a modern subdivision. The Hahaione Stream is channelized, and all of the utilities are underground. When Hahaione Stream left its channel, due to blockage by debris, it followed its historic course down Kahena Street. The water and debris rapidly eroded the asphalt and the fill roadbed. In the course of this erosion, all of the utilities were damaged for the 54 houses along Kahena Street. The street was eroded to depths of 15 feet. Fortunately, most houses were only lightly damaged except for the structures along the path of the stream's return to its channel. However, residents of Kahena Street had no utilities and no street access.

Immediate responses to the problems of Kahena Street included emergency road reconstruction, installation of portable toilets, installation of temporary telephone booths along the street, use of water supply trucks, and installation of temporary power lines for electricity. Reconstruction of Kahena Street took 3 months to complete.