Heavy rain caused isolated flooding in parts of Oahu on Sunday, continuing a run of wet weekends that has helped to ease drought conditions around the state.
Oahu was under a flash flood warning for much of the day as moderate to heavy downpours caused Waikane and Waiahole streams to rise.
During the warning period, radar showed locally heavy rain over the Koolaus falling at a rate of 1 inch or more per hour.
The rising waters of Waikane Stream built up under the Kamehameha Highway bridge Sunday afternoon. The stream slightly overflowed its banks near the bridge, causing puddling on Odeleen Davis’ property on the Kamehameha Highway roadway and creating hazardous driving conditions.
Davis said Sunday’s flooding wasn’t nearly as bad as it has been in the past, but it represents a continuing concern.
"The river hasn’t been cleaned for long time from the city and county (of Honolulu)," she said. "It’s all plugged up under the bridge. We’ve got tree stumps underneath there, so that’s why we always have this backup coming into our yard."
Davis said the city used to maintain the area of the stream where tree stumps and debris collect, but it’s been a while.
"Two years ago they used to bring in the heavy equipment, and they used to go over the bridge with the heavy equipment and scoop it out," she said. "But they haven’t done this in a very long time now."
A weakening weather system and tradewinds blowing rain clouds over windward areas are blamed for the wet weekend on Oahu and Maui.
Forecasters say the wet conditions in windward and mauka areas could continue through today.
Rainfall totals reflect the steady moderate to heavy rain over Windward Oahu. Waiahole recorded 6 inches of rain in the 24-hour period ending at 2 p.m., with much of the rain falling in the previous 12 hours. Kahana, the Oahu Forest National Wildlife Refuge, Ahuimanu, Moanalua and the Halawa Tunnel all got more than 5 inches of rain.
According to the National Weather Service, rainfall produced by late-season cold fronts improved vegetation conditions and remedied what had been a drought. Several rain gauges in West Oahu recorded their highest April rainfall totals in more than 20 years, the weather service reported.
Increased rainfall helped other islands in the western half of the state to emerge from drought during the 2012-2013 wet season.
Satellite information shows improving conditions on Molokai, enough for the state Department of Agriculture to change the mandatory reduction in irrigation water consumption for farmers served by the Kualapuu reservoir to 20 percent from 30 percent.
On Lanai, rainfall over past week appears to have halted a deterioration in agricultural conditions over the last month.
Kauai does not currently have any areas in drought.
Despite improving conditions on those islands, drought continues to plague Maui and Hawaii island.
According to the weather service, a lack of tradewind rainfall resulted in very dry conditions in April, normally one of the wettest months of the year for eastern slopes of the Big Island. Extreme drought persists in a portion of Pohakuloa and the lower slopes of South Kohala near Kawaihae and Puako. Severe drought continues to affect the rest of South Kohala and the upper slopes of North and South Kona.
On Maui, extreme drought conditions are present over the southwest slope of Haleakala, including the Kihei, Kamaole and Ulupalakua areas. Severe drought continues along the lower southeast slope of Haleakala near Kaupo and the lower elevations of West Maui from Maalaea to Kaanapali.
