West Maui road, bridge repairs from Olivia ongoing

Over 80 storm damage reports received so far

Heavy rains from Tropical Storm Olivia as it passed over Maui County on Sept. 12 sent floodwaters roaring down streams in West Maui. The water overwhelmed culverts and ran over bridges along Lower Honoapiilani Highway in Kahana and Honokohau. KELLY PITZER photo

State and county departments are repairing roads and infrastructure damaged by last week’s floods from Tropical Storm Olivia in West Maui.

The Department of Water Supply on Thursday afternoon asked customers in Kahana, Napili and Honokowai to conserve water until the end of the month. The Honolua Ditch, which supplies surface water to the Mahinahina Water Treatment Facility, is under repair and maintenance due to Olivia, the department said.

The department asks customers to conserve water when possible until the ditch system can be cleared by the end of the month.

Maui County Public Works crews from Makawao and Lahaina were repaving Lower Honoapiilani Road on Thursday and have cleaned out damaged sections of the road, Deputy Director Rowena Dagdag-Andaya said. The road was undermined by the Sept. 12 flood that warped the asphalt and overwhelmed a culvert structure on the road.

Dagdag-Andaya said the road is open with one alternating traffic lane, while workers continue to fix the road. She said temporary repairs cost about $50,000, though a permanent fix could cost well over $100,000.

“We’re working with the water department and Planning Department as well as members of the community to come up with the permanent fix,” she said.

Maui Emergency Management Agency officials also conducted damage assessments of Honokohau Valley to build a case for federal aid. Red Cross officials assisted in gathering data, and the agencies plan to finish their report in the next several days.

Emergency Management Agency Administrator Herman Andaya said the county received about 65 reports of storm damage — from minor damage to complete destruction. He said about half of the reports were from residents of Honokohau Valley and 18 new reports still need to be vetted.

“It’s difficult because there’s no addresses, so we’re still trying to figure out which of these homes are damaged,” Andaya said.

The county Water Supply Department has said it has repaired the water system feeding into the valley and is conducting quality samples. Repairs were estimated to cost $100,000, and water should be flowing to residents early next week.

Other work slated for the area includes $3 million to rehabilitate and improve Honolua Bridge, which was overtopped but undamaged by floodwaters.

The state Department of Transporation has proposed to keep the structure between milepost 32.40 and 32.51 a one-lane bridge, according to a draft environmental assessment published Sept. 8 by the Office of Environmental Quality Control. Rehabilitation work includes a superstructure with a load capacity that meets federal standards.

The bridge, built in 1924, does not meet federal standards for highway bridges in terms of “geometrics, weight load capacity and hydraulic capacity,” according to the draft assessment. The existing bridge has a National Bridge Inventory sufficiency rating of 42.2 out of 100. Any score below 50 warrants replacement or rehabilitation.

The proposed bridge is to remain 18-feet-wide and be improved to have one 12-foot-wide travel lane and one 5-foot-wide shoulder for pedestrians and bicyclists on the makai side. A 1-foot-wide shoulder is proposed on the mauka side along with bridge rails on the makai bridge parapet.

Construction is expected to begin in fall 2020 and completed within four months.

Currently, there are no accommodations for pedestrians or bicyclists on the existing bridge. A temporary traffic detour road and temporary bridge will be built on the makai side of the highway right-of-way to allow the road to remain open during the construction period.

Once construction is completed, the temporary detour route and bridge will be removed and the area restored to its original condition, as much as possible, according to the draft assessment. No work will occur below the existing bridge abutments or within the stream bank.

Residents requested the bridge remain one lane and believed widening it would open the area to development and encourage speeding. Residents support the bridge upgrade for safety purposes but asked for minimal impacts to water resources and historical structures.

State DOT Maui District Engineer Robin Shishido said last week he sent two engineers to inspect Honolua Bridge, which was “structurally fine” and endured “only minor erosion.” He said there was no major damage to any state bridges, but it was a close call.

“Anytime you have major flooding or overtopping of bridges, the foundations can be eroded or undermined,” Shishido said. “As soon as it’s safe, we always send out an assessment team.”

* Chris Sugidono can be reached at csugidono@mauinews.com.

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