Heavy rainfall along the Kona Coast triggers a Flood Advisory and causes flooding and heavy runoff in the areas around the Kailua-Kona and Captain Cook Thursday afternoon and evening (November 26th).
HIRSC - Hawaii Island (Holualoa) and Utah (Saint George) Team
It was a wet Thanksgiving afternoon and evening (Thursday, November 26th) for many along the Kona Coast. The heavy rainfall began around 4:00 pm Thursday afternoon, triggering a Flood Advisory for the Kona Coast until 8:30 pm Thursday evening. Radar showed rain falling at rates of 1-2 inches per hour with some areas seeing as much as 1.5 to 3 inches in a one-hour period.
HIRSC - West Hawaii Team members reported thunderstorms and few flashes of lightning happening in the higher elevations above Holualoa and Captain Cook.
Rain gauges along the Kona coast recorded the following amounts (ending at 8:45 pm - courtesy of Wunderground PWS)
7.89 inches in Keopu Mauka
7.18 inches in Kailua View Estates
5.69 inches in Hualalai Acres
5.43 inches in McCoy Plantation
4.39 inches in Pualani Estates
3.98 inches in Keokea (Honaunau)
3.48 inches in Captain Cook (near Coffee Shack)
3.43 inches in Keauhou Mauka
2.87 inches in Kona Vistas subdivision
2.11 inches in Komohana Kai subdivision (off of Lako Street - makai of Kuakini Highway)
1.95 inches near Palani Junction (Kailua-Kona)
1.77 inches in Pines II subdivision
Following the heavy rainfall above Kailua-Kona, numerous gulches and streams including the Wai'aha River began to flow with water. At 6:55 pm Thursday evening, the Wai'aha Stream flow gauge located near the Wai'aha Bridge on Highway 180 (Mamalahoa Highway) in Holualoa recorded a flow rate of 1,150 cubic feet per second, however, shortly thereafter began to slowly subside.
Heavy runoff flowing down Wai'aha Stream and Holualoa Gulches also caused flooding and heavy ponding on Kuakini Highway between Pottery Terrace and the Queen Kaahumanu Highway junction. The Hawaii Fire Department (HFD) responded to the area and investigate and confirm the hazardous condition reported by motorists and residents.
The Hawaii Police Department (HPD) later closed a 1-mile section between Queen Kaahumanu Highway and Oni Oni Street intersections while Department of Public Works (DPW) crews worked to clear the culverts and also any debris on the roadway. Parts of Kuakini Highway was damaged as a result of the heavy runoff and DPW crews were also in the process of mitigating the hazard as well.
HFD, HPD, and DPW crews responded also to investigate heavy runoff from the Holualoa Gulches also overflowing onto Ali'i Drive near Kona Bali Apartments in Kailua-Kona. No flood damage to residents near the Holualoa Gulches was reported and motorists were still able to safely navigate Ali'i Drive near the Holualoa Gulch culvert, where minor ponding was found and the water level at the Holualoa Gulch was beginning to slowly subside following the rain dissipating.
Other reports of heavy ponding and runoff were reported in the Holualoa, Keauhou, Kainaliu, and Captain Cook areas of the Kona Coast. DPW crews will be continuing through the rest of Thanksgiving evening and early Friday morning (November 27th) to clear the hazards reported.
HFD and HPD responded to one call for a report of nuisance flooding at a residence off of Kinue Road in Captain Cook on Thursday evening. No injuries were reported and no extent of damage was given from this incident.