(Hanalei, Kauai) – Kauai taro farmer Rodney Haraguchi can’t wait until the Hanalei Stream Bank Restoration Project is finished in the next two months. For almost 20 years, he and nine other farmers who have loi on the U.S. Fish and Wildlife Services’ Hanalei National Wildlife Refuge have experienced diminished water flows from the Hanalei River. “You know, like any farmer, without water, you cannot plant any taro or harvest; water is the life-line for our crops,” Haraguchi said.
No one knows for sure what caused the embankment to breach which lead to diminished stream flows, beginning in the mid-1990s. Some speculate it was the result of a massive landslide far upstream in one of the mountain valleys. Whatever the cause, the result has been a serious reduction in flow to an inlet pipe which takes water from Hanalei Stream to the farmer’s loi. Upstream from the pipe the river changed course over time and much of the river flows were diverted into the breached channel.
AECOM Technical Services, Inc. was contracted by the DLNR Engineering Division to design the current stream bank restoration project. The senior engineer for the project, Ardalan Nikou explained, “What happened was, eventually the farmers started noticing less water coming into their farms. We need the volume to get around a bend where the inlet pipe is located. By losing water through part of the stream bank that breached, the farms and wildlife refuge have not received the volume of water they need.”
The stream bank restoration involves building an earthen berm, with all the elements of a small earthen dam. The engineers and contractors have employed best management practices (BMPs) discussed with and approved by the Hawaii Dept. of Health and the U.S. Army Corps of Engineers to minimize the amount of silt and brown water that flows from the construction site, downstream, and into Hanalei Bay during heavy rain events. Carty Chang, administrator of the DLNR Engineering Division said, “If we had not done this project, Hanalei Bay would continue to be in jeopardy as the breached channel would continue to erode and deposit sediment into the Bay. While it’s impossible to provide a 100% silt-proof system in a high-energy river like Hanalei Stream, we’re confident the stream bank restoration project will have the intended result of restoring adequate flows for farmers and the wildlife refuge, as well as reduce the amount of sediment from flowing into Hanalei Bay during and after rain events.”
Farmer Rodney Haraguchi is just excited that Hanalei Stream will soon return to its natural course and normal flow. He said, “I think everybody needs to be calm, do their homework and realize that this is the best route. For 20 years we farmers have been up in the air about the water flow; it’s been like a big dark cloud over Hanalei and now it’s about to lift.”
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HD Video of in-stream restoration work:
Photographs of in-stream restoration work:
Talk Story with a Hanalei Farmer:
Talk Story with a Hanalei Engineer:
All video and images courtesy: Hawaii DLNR
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Hawaii Department of Land & Natural Resources
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Honolulu, Hawaii 96813