The price tag to bury miles of existing overhead utility lines along the Wai'anae Coast and remove precarious poles could easily cost "tens of millions of dollars" and might raise utility rates, state and Hawaiian Electric Co. officials said yesterday.

How much of the 17 miles of lines to bury along Farrington Highway will be decided after community input over the next several weeks, state Sen. President Colleen Hanabusa said.

Placing the Wai'anae power lines underground will cost an estimated $12 million per mile, said HECO spokesman Darren Pai. That equals $204 million for the 17 miles.

That estimate only covers HECO's lines and does not account for burying other companies' lines that use HECO's poles, Pai said.

By contrast, a 2006 Mainland study by the Edison Electric Institute — the association of U.S. shareholder-owned electric companies — estimates the cost of burying existing overhead power lines at $1 million per mile.

HECO's $12 million-per-mile estimate seems high, even considering Hawai'i's labor costs, said Henry Curtis, executive director of Life of the Land — which has monitored HECO's recent transmission line projects.

'SHARES THE CONCERNS'

Curtis also said the Wai'anae work is certain to run into unanticipated delays, such as the inevitable discovery of ancient Hawaiian bones, or iwi.

He also said the terrain that varies from sand to basalt will cause problems and the project will encounter "other obstacles along the coast, from lava tubes to caves to coral to coastal erosion that might have to push some lines farther inland. It will not be a simple job."

Curtis wondered what the actual total will be. "Who will pay for the undergrounding of Oceanic's lines?" Curtis asked.

Alan Pollock, spokesman for Oceanic Time Warner Cable, said Oceanic has no estimate for what it might cost to bury its lines and hasn't been approached by anyone about participating.

"Basically, we're in the dark," Pollock said. "No one's contacted us on this. Certainly we're going to have to make some kind of arrangements. But at this point in time we have zero information to go on. We're going to be expecting a call, hopefully soon, from HECO on this."

Hawaiian Telcom spokesman Ann Nishida said in a statement that "Hawaiian Telcom shares the concerns expressed by the Leeward community and fully supports the initiative to explore options for the utility lines along Farrington Highway.

"The cost to underground Hawaiian Telcom's facilities would depend on a number of presently unknown factors, such as soil conditions in the area, the amount of facilities on the poles and the number of parties sharing the trenching costs as just a few examples.

"With that said, we expect our costs to be lower than the HECO estimate provided as we do not have to address the same safety issues associated with undergrounding high voltage lines."

University of Hawai'i professor Karl Kim, chairman of the department of urban and regional planning, had no calculations to compare against HECO's estimates but said, in general, "it is good practice to bury power lines."

"There should be some safety benefits associated with doing that," Kim said. "I would say it's a positive step in the right direction. But any time you make a change, there is going to be inconvenience."

COMMON OCCURRENCE

On Dec. 5, 16 utility poles along Farrington Highway snapped or were bowled over by wind gusts up to 70 mph, knocking out power to hundreds of HECO customers for days and choking traffic on the Leeward Coast.

Some of the damaged poles had been replaced little more than a year before, when strong winds in March 2006 toppled more than a dozen poles.

Some Leeward communities that have not had utility poles blow over probably will prefer to keep the rustic, rural feel of having overhead lines attached to wooden utility poles — just like some North Shore communities, Hanabusa said.

But those that want lines underground will not see the work completed for at least another two or three years, she said.

Some of the cost to pay for the project might come from federal funds, bonds or higher rates, said Hanabusa and Robbie Alm, HECO's senior vice president. Alm said the project could easily run into the "tens of millions of dollars."

Hanabusa compared the potential funding for the project to the work burying utility lines in the late 1980s and early 1990s when Kalaniana'ole Highway was widened out to Hawai'i Kai.

The first, $10.4 million phase between Wailupe Circle and East Halemaumau Street was evenly divided between the state Department of Transportation and HECO, according to PUC documents. Costs for later phases of the project were shared between the state and HECO but not evenly, the documents showed.

Any rate increase tied to the Wai'anae project would not be seen immediately. HECO does not get PUC rate increase approvals for individual projects but could seek a rate increase for several projects that might include the Wai'anae work, HECO spokesman Pai said.

Reach Dan Nakaso at dnakaso@honoluluadvertiser.com.