Oahu reservoirs all need help
Overgrown vegetation and erosion head the list of deficiencies, none critical, on dam inspection reports
Each of Oahu's three largest reservoirs is suffering from a lack of maintenance -- and the island's smaller man-made lakes aren't in great shape either, according to dam inspection reports made public yesterday.
Among the problems listed in a report posted on the state Department of Land and Natural Resources Web site:
» Some of the trees on Nuuanu Dam are as big as 2 feet in diameter, much larger than the 2-inch diameter maximum recommended for woody plants on a dam. Tree roots can create openings for piping -- water flowing through the dam and weakening it.
» An old landslide, three nonworking intake valves and erosion are on the to-do list for Lake Wilson's Wahiawa Dam.
» The Kaneohe Dam at Hoomaluhia Reservoir needs to trim tall grass and bushes, improve access in wet weather and figure out what's causing seepage.
Recommendations for Oahu's smaller dams and reservoirs cover the same ground: more trimming of green stuff, repairing of erosion and making sure the dam's structure is sound with geotechnical studies, according to the reports.
None of the dam and reservoir shortfalls identified created "imminent danger to life and property" when the inspections were made the first week of April, says a summary of the reports jointly issued by the state DLNR and the U.S. Army Corps of Engineers.
But they do urge dam owners -- both private and government -- to get going with plans to make things right.
The whole exercise was set in motion by the tragic breach of the Ka Loko Dam on March 14, which killed seven and washed away two homes.
Inspection reports released last month for Kauai found fault with all 54 dams inspected there. Big Island and Maui results are to be released in the next two weeks, DLNR Deputy Director Bob Masuda said yesterday.
Not keeping bushes, trees and grass in check "has been a recurring deficiency that we have noted previously" in DLNR dam inspections, Masuda said.
"Vegetation can be a hazard, depending on where it grows," Masuda said. "It can hamper the ability to do inspections" by blocking a good view of the condition of a dam or spillway. And it can do damage with its roots."
The Honolulu Board of Water Supply, which owns the Nuuanu Dam, is poised to spend up to $500,000 on improvements this year, spokeswoman Su Shin said.
The money was appropriated before the inspection results were released, but won't be enough to do all that's needed, Shin said. The board will have to prioritize its greatest needs, she said.
"We knew these issues were out there and wanted to address it," Shin said. The board's response to the state's request for a work plan will "advise them what steps we've already taken and what additional steps we will take."
Dole Foods' corporate office in California is reviewing the state report and will develop an action plan, said Dan Nellis, Dole's Oahu operations director. Dole owns four dams on the list.
Officials with the city's Department of Facility Maintenance said yesterday they were reviewing the report before making any comment.
Most of Oahu's dam-created reservoirs checked out by inspectors are small: Seven are 100 acre-feet or less and five are 700 acre-feet or less. An acre-foot is the equivalent of one acre of water at one foot deep.
One that's on the list doesn't exist anymore. The Army's Ku Tree Reservoir east of Wahiawa was breached years ago and has no capacity.
The Kailua Reservoir in Waimanalo was a concern in early April when it swelled with rainwater, but has since been breached as a safety precaution.
The Department of Land and Natural Resources is giving dam owners the following deadlines for action:
» Three weeks after receiving the inspection report: Provide DLNR with an explanation of immediate actions to address hazardous concerns; update emergency contact information.
» As soon as possible, but before Nov. 30: Written report of how the owner will address all deficiencies identified as requiring immediate action.
» By Sept. 30: Provide a short-term plan of work needed to bring the dam to acceptable condition, with a projected timeline for completion and estimated cost. This would include studies (geologic, hydraulic, etc.), vegetation maintenance and operations plan. Update records with state including Emergency Action Plan, site plan, past operation and maintenance reports, inspection reports and engineering studies.
» By Dec. 31: Provide formal, long-term plan for improvement, including any studies, analysis or investigations conducted in short-term plan.
ON THE NET
The Kauai and Oahu dam inspection reports, a list of Hawaii dam owners and other information about dams and dam inspections can be found at www.hawaii.gov/dlnr
Source: Hawaii Department of Land and Natural Resources
Kauai dam report sets Nov. 30 deadline
Owners have until Nov. 30 to fix problems with their Kauai dams listed as having at least one "detrimental condition" in a report last month, a spokes-man for the Department of Land and Natural Resources said recently.
The report said the condition of the dams, if not properly maintained, could lead to future failure. Three owners of a majority of Kauai's dams say they're already working on getting the problems fixed.
Grove Farm Co., A&B Properties Inc. subsidiary Kauai Coffee Co. and the state account for 38 of the 54 dams on Kauai.
All three say they've started fixing the problems identified in last month's report and are putting together a plan with the state.
"We have submitted a plan to the DLNR in response to the dam reports, outlining actions already undertaken as well as those being pursued and to be pursued," said Frank E. Kiger, president of Kauai Coffee Co. "We will continue to work closely with the state to address identified maintenance and repair issues and to undertake requested studies."
Kiger said all the company's reservoirs, which are used to provide irrigation, are monitored daily and maintained regularly.
A&B's Alexander Reservoir, the second-largest on Kauai, was found with numerous problems, mostly caused by high vegetation growth and a rock slide nearby. But no imminent threat was detected.
Kiger said repairs at the difficult-to-access Alexander Reservoir "is a high priority" and "we are working closely with state government to undertake the needed work."
At the state reservoirs, Clifford Inn, a DLNR spokesman, said action plans are being put together for all state dams on Kauai. They are also planning to decommission and remove two dams, Field 1 and Field 2 Kealia reservoirs north of Kapaa.
At Grove Farm, which owns seven reservoirs, workers are in the process of tasks such as clearing brush from walls, spillway and inflow and outflow channels.
"We check them off the list as we accomplish them," said Grove Farm Vice President Marissa Sandblom.
Urgent corrective action required in the state report at Aii Reservoir, regarding the outflow from the spillway coming close to the bottom of the dam wall, has already been fixed, Sandblom added.