A raging stream that caused a Hau'ula home to fall into its waters is cutting a new channel to Kamehameha Highway, threatening the stability of the only thoroughfare through that area of Windward O'ahu.

But the state is planning an emergency fix starting today to stabilize the banks of Kaipapa'u Stream and adjust the flow of water.

Flash flooding dissolved the banks of Kaipapa'u Stream during a storm last month, taking more than 15 feet of land and the foundation under Shaun Ka'ana'ana's home, which fell 12 feet into the water below.

"It changed the direction of the stream and now it's headed for the road," said Brennon Morioka, director of the state Department of Transportation, which has responsibility for the highway and its bridges.

A concrete retaining wall along the stream once protected Ka'ana'ana's property, but the wall crumbled last year during another storm.

Then, on Nov. 13, a flash flood took away most of the land under Ka'ana'ana's home, a one-bedroom apartment unit that was attached to a carport. The unit hung over the stream for a day, and the next night, more flash flooding doomed the structure.

Now the highway faces the same fate as the stream erodes land below it. With the wet season just beginning, the DOT has decided to fix the problem even though it's on private property.

HEALTH, SAFETY ISSUE

The stream belongs to the property owner on the opposite bank of Ka'ana'ana's home, Morioka said.

"This is a health and safety issue for the public," he said. "The consequence is that we lose the road and the community is completely cut off, including emergency services."

If the highway fails, residents would be cut off from groceries, the post office and medical treatment at the Hauula Shopping Center. Unknown others also would have to find new routes to work and face the possibility of two-hour commutes around the North Shore and into Honolulu.

"It would impact everybody in this area because we wouldn't be able to get into the only shopping center in Hau'ula," said Dotty Kelly-Paddock, a member of the Ko'olauloa Neighborhood Board. "We take our kids to school that way."

Her husband, Peter Paddock, said a huge concrete structure that was once part of a railroad truss sits in the middle of the stream, diverting water to the eroded property and the highway.

"If something isn't done right away, the road will wash out in the next big storm," Paddock said.

Kelly-Paddock said she was shocked to learn that help was available last year when the retaining wall came down and the house was threatened.

The Natural Resources Conservation Service was poised with expertise and money to help, but no sponsoring agency from the city or state stepped forward, said William Hollingsworth, NRCS state conservation engineer. A sponsoring agency is necessary to get the funds, Hollingsworth said.

Through the Emergency Watershed Protection Program, the NRCS provided about 75 percent funding to mitigate erosion problems in Ka'a'awa in Makaua Stream after a 40-day storm in 2006 washed out stream banks and threatened eight homes.

"We looked at that (Hau'ula) home after the December 2008 storm, and we worked to see if there would be a sponsor," Hollingsworth said. "No one was interested in sponsoring a project to fix the stream."

The state Department of Land and Natural Resources was the sponsoring agency for the Makaua Stream, which is privately owned.

PRIVATE STREAM

In that project U.S. Sen. Daniel K. Inouye, D-Hawai'i, obtained $300,000 to fund an Army Corps of Engineers study for Makaua Stream. The state share of the project came from an emergency appropriation intended for remedial work caused by the 2006 flooding.

"(Hau'ula) was not a DLNR jurisdictional matter because the stream is privately owned," said Deborah Ward, DLNR spokeswoman. "In accordance with state law, stream maintenence is the responsibility of its owner."

City spokesman Bill Brennan said he was not able to determine who in the city might have been asked to sponsor the project, but thought a project of this nature would most likely fall to the state.

The DOT met with several agencies last week to discuss the problem with the stream and road, said Morioka, DOT director.

Part of the focus was on stream management and working in partnership with city, state and federal agencies to educate the public and private landowners who own portions of the stream about their responsibilities, he said. The group talked about developing a plan or program to establish protocols and communication, Morioka said.

The stream's private ownership complicates things, but the DOT feels a sense of urgency to resolve the problem, Morioka said.

The fix includes clearing the house debris from the stream and lining the banks with six-foot sand bags covered with concrete mat. The contractor, Hawaiian Dredging, also will remove other debris that changed the course of the stream.

That should realign the stream to its old course, sending water under the bridge and out to sea, Morioka said.

The DOT is working on a permanent fix that may be included in a project to replace the bridge next year, he said.

The cost of the emergency repairs is not yet known, Morioka said.

"But basically we need to do this regardless of the cost," he said, "because it's a matter of saving the road."