Oahu's torrential downpours created East Oahu's worst flooding in three decades.                
 As residents clean up mud filled homes, the damage of Friday's flooding disaster is being added up. 
        
The flood waters have receded from Camm Willener's Niu Valley home, just like it has for most of his neighbors, but the memories of the downpours are still fresh in his mind.
"All the way up the hill, there were just fountains of water streaming from people's homes. It was like nothing I had ever seen before. It was scary."

The rain was intense, more than 5 inches coming down in just 1-2 hours.

"We're talking about 4-5 inch rainfall rates. That kind of intensity will produce flooding just about anywhere," said National Weather Service Hydrologist Kevin Kodama.

Kodama said extreme rainfall events are also extremely challenging to predict exactly where they will hit, or even how intense they will turn out.  

"When you are talking about extreme events like this, they are very difficult to forecast. Sometimes even the most subtle features can explode into significant weather systems," added Kodama.

When the downpours exploded over East Oahu, water levels quickly rose along Wailupe Stream and the force of the raging waters ripped out vegetation and even trees along the banks. It also lead to flooding of some nearby homes.

"There was a coconut tree that was backed up at the bridge and it blocked off everything. So the stream overflowed from the back," said Aina Haina resident Peter Tuohy.

"Along Niu Valley Stream, was pouring out of the canal...just overflowing. It destroyed all the homes on the other side and the muddy water was just flowing like a torrent," stated Willener.

"It is not a question of not having capacity because of the silt, mud, rocks. We had so much rainfall that the volume of water overwhelmed the drainage infrastructure we have in place," said Dept. of Facility Maintenance Director Ross Sasamura.

Since the flooding, city and state crews have been busy clearing out the clogged waterways. 

Some of which had 1,000,000 gallons of water coming out every minute during the height of the storm. All that runoff was equivalent to a 25-50 year flood.
One U.S. Geological Survey stream gauge found the last time water levels were higher, was 30 years ago during the New Year's Eve floods.

Which is also a reminder that even though these extreme events are hard to predict, they do happen in Hawaii.

"We've seen these really intense thunderstorms over the water, and it doesn't affect anybody.
What happened on Friday was it moved on shore," added Kodama.

The unpredictability of Hawaii's extreme weather worries Willener and others still focused cleaning up from the current disaster.

"I don't want to live in this house under these circumstances. Flooding has happened before. It is going to happen again. My family is scared to death," said Willener.

Because of the massive amount of runoff, two ditches and one stream sustained damage from the floods. The city will now start emergency repairs to fix those three waterways in East Oahu.