Flash flooding from Tropical Storm Darby has left a mess on Oahu.
Oahu residents woke up Monday morning to emergency traffic crews clearing debris from the roadways.
With water pouring down onto the H-1 Freeway for most of the night, some drivers took a chance driving through the flood and wound up getting stuck. That forced Honolulu Police to shut down all westbound lanes between the Lunalilo and Likelike off-ramps.
State officials say the drainage system along the freeway was just overwhelmed.
“The sheer amount of water that came down all at once may have exceeded the capacity for those drainage canals and those drains on the freeway,” said transportation spokesman Tim Sakahara.
Sakahara says crews immediately checked it last night and the drains were not clogged, so DOT is looking into how to improve the system and figure out “if indeed the drainage system was overcapacity or it wasn’t able to accommodate all this water all at once, what can we to make it better and prevent it from happening again.”
Sakahara adds that damage to the curb on School and Liliha streets, above the freeway, might have also contributed to the flooding because the curb diverted water away from the drains on the roads.
“Some of the trees that are there might have buckled the curb so that might have contributed to some of the water going over and then down on the embankment into the freeway instead of going down the curb and then on to the next drain,” he explained.
On Dillingham Boulevard, crews were working to clear all the debris that washed up from Kalihi Stream. The road remains closed in both directions at Middle Street.
City officials tell us that there was so much debris that washed up that it served as a dam as it reached the bridge on Dillingham Boulevard.
City officials said crews checked the stream right before the storm but didn’t anticipate the large debris, which they say probably came from residents from way upstream.
“A lot of the debris that actually accumulated here are items that we wouldn’t have been clearing in the first place,” said Ross Sasamura, Department of Facility Maintenance director and chief engineer. “It’s large trees so if you look at this area, the size of the trees that are involved, I don’t think came from the immediate vicinity.”
City crews are working to remove mud and debris from TheHandi-Van lot, located at the corner of Middle Street and Kamehameha Highway, which was flooded overnight.
Oahu Transit Services says mud and debris got into about 25 of the city’s vehicles. Thirteen of them will need to be repaired.
OTS says crews were able to move some of the vehicles to higher ground as the weather worsened Sunday night.
“By 9 p.m., they were aware that the water was rising. They started moving vans and by 9:30, they told me, it just started coming down cats and dogs in a huge deluge,” said OTS president Roger Morton.
Handi-van users should expect delays due to the shortage.
The entire island of Oahu is under a brown water advisory, and state and city officials have reported numerous sewage spills around the island.
“We maxed out. We were ready to break at Sand Island, but the collections systems staff, they held back some of the flows at the Ala Moana pump station and Beachwalk. Unfortunately, there was a small spill at Atkinson,” said Lori Kahikina, Department of Environmental Services director.
“The public is advised to stay out of flood waters and storm water runoff due to possible overflowing cesspools, sewer manholes, pesticides, animal fecal matter, dead animals, pathogens, chemicals, and associated flood debris. Not all waters may be affected, however if the water is brown stay out and continue to practice good personal hygiene and follow up with your primary care physician if you have any health concerns.” – Clean Water Branch, Department of Health
CWB was notified by CCH of a sewage discharge from Kailua Regional Wastewater Treatment Plant. Approximately 42,000 gallons entered a storm drain leading to Nuupia Pond.
The city reported a 4,200-gallon spill at Kaneohe Pretreatment Facility. Kawa Stream overflowed its banks, entered the facility, and flowed back into Kawa Stream. It started at 11:30 p.m. July 24 and stopped by 3 a.m. July 25.
Crews received a call of a manhole overflowing and found evidence of a spill at 44-217 Mikiola Drive, but it ended by the time they arrived on-site.
The City and County of Honolulu’s Department of Environmental Services (ENV) responded Sunday night to a sewer overflow near Ala Moana Shopping Center. Officials estimate the preliminary volume to be more than 1,000 gallons.
The Honolulu Fire Department saw two manholes overflowing at the intersection of Atkinson Drive and Ala Moana Boulevard and notified ENV. ENV crews arrived on scene at 10 p.m. and stopped the spill at 10:20 p.m.
The public is advised to stay out of the waters of Waolani Stream from Wylie Street to the mouth at Honolulu Harbor.
CWB was notified by City and County ENV of a wastewater discharge from 2411 Waolani Avenue. The estimated 1,200 gallons flowed into the street and into a storm drain that empties into Waolani stream at the Wylie Street crossing. The discharge has been stopped.
On Sunday, CWB was notified by CCH of a sewage discharge from a private residence located at 2407 Liliha Street. An estimated volume of 4,100 gallons was discharged and entered into Waolani Stream.
Two-thousand-four-hundred gallons spilled into a storm drain at the corner of Hala Drive and Aupuni Street Monday morning. Officials say it was caused by grease.
CWB has been notified of a pump station manhole overflow at the Punawai Pump Station in Heeia. Heeia Stream overflowed and flooded the pump station. About 600 gallons of wastewater entered into Heeia Fishpond.
The public is advised to stay out of these areas.
Hawaiian Electric has been responding to storm-related outages across the island through the night and day.
Several areas remained out of power for more than 12 hours. Some areas, according to the utility, were inaccessible due to flooding.
Fort Street Mall Satellite City Hall
The City and County of Honolulu temporarily closed the Fort Street Mall Satellite City Hall, located at 1000 Fort Street Mall, due to flooding related to Tropical Storm Darby.
This location is below King Street in downtown Honolulu.
All other Satellite City Hall and Driver Licensing Centers are open and operating on regular schedules.
The Department of Customer Services encourages customers to also use online services whenever possible.
University of Hawaii John A. Burns School of Medicine
The University of Hawaii John A. Burns School of Medicine campus in Kakaako was closed Monday due to the flooding of a nearby power substation. This also affected the UH Cancer Center. All facilities will reopen Tuesday.
Only essential workers allowed into the secure biosciences building.
The closure does not affect operations at the Gold Bond Building, which remains open.