Shoreline repair solutions sought
Residents oppose seawalls; other options considered for Lower Honoapiilani Road
NAPILI — Maui County Public Works officials are mulling long-term shoreline repair solutions for a 30-foot section of Lower Honoapiilani Road, which is in danger of collapsing and shutting down utilities for nearby residents if another major storm were to hit.
The department presented a handful of permanent shoreline protection alternatives and a plan for temporary repairs to about 70 West Maui residents Tuesday night at Maui Preparatory Academy. Many residents asked the department whether road damage stemmed from culverts being overwhelmed during storms. They also asked when temporary repairs or a permanent fix would be completed.
Sea Engineering Inc., a coastal engineering firm hired by the county, discussed the findings of its scientific study on shoreline erosion along Lower Honoapiilani Highway at Kaopala Bay.
“Something needs to be done right away, and the state and county in my opinion should eliminate all the paperwork that has to be done before this,” said Caitriona Vigliotti, who uses the road to reach her home on Puamana Place. “If another storm comes in, we’re going to get more waves and more breakouts of the culvert.”
Public Works Director David Goode said the department is working on temporary repairs, but it’s awaiting approval by the state Department of Land and Natural Resources’ Office of Conservation and Coastal Lands. The county Planning Department already approved a temporary rock revetment project, but the state rejected it in favor of large sand bags, he said.
Public Works officials also noted that no funds have been secured for design or permitting of a permanent repair, and construction is at least two years away.
“It’s frustrating because we have two agencies that don’t agree with each other,” Goode said, adding that the area has existing rock revetments. “We’re going to work with them (DLNR) because we need to do something right away to protect the road and utilities, which if they blew out would be an environmental disaster. We’re looking to get that done as quickly as possible.”
The lower road serves as a major collector for traffic and as an alternative to the highway. Floodwaters from Tropical Storm Olivia warped and undermined the road on Sept. 12. Public Works crews repaved and cleaned out damaged sections of the road, which was reopened shortly after the storm.
Engineer Kristi Ono told residents during Tuesday’s meeting that erosion of the road worsened because of storm runoff. She showed photos of the roadway shoulder displaying signs of failure. She said the road serves several subdivisions and an hourly bus service that connects Napili to Kahana.
She also highlighted the potential damage of two large water transmission lines, a 16-inch waterline and 21-inch sewer line, beneath the road.
“A blow out of a pressurized line of that size could damage the sewer line and would be pretty much a disaster for us right by the ocean,” she said.
Ono said the department wanted to line the exposed eroded cliff with large stones to match existing rocks on the shoreline. However, the DLNR requested the sand bags because they’re “removable.” She said the geotextile sandbags could be installed “pretty quickly” using in-house workers and materials available in the state.
“It all depends on the state,” she said. “We hope to start as soon as possible, but it’s hard to judge.”
DLNR officials could not immediately comment Wednesday afternoon.
Goode said the state was “quite adamant about not having rocks,” which he said he thinks state officials view as potentially setting a precedent for shoreline armoring. He countered, though, that the project is for a public road that serves other functions and not a private landowner.
“A lot of people are connected to those lines,” he said. “I don’t know exactly, but it could go all the way to Kapalua for all I know.”
At its narrowest, the utility lines are just a few feet from being exposed and under pressure, Goode said. Crews needed to remove kiawe trees from the area after the storm tore them out of the ground.
Goode said he believes the project could be the first of many the county faces as more coastal roads, such as North Kihei Road, face erosion from rising sea levels.
“Our department will likely ask the council for funding to start doing detailed studies on what we do in these areas where sea level rise is going to cut off roadways,” he said. “This one is kind of at the forefront because of the wave action in this area.”
Among the alternatives the county presented to West Maui residents were a cement-rubble-masonry seawall, a rock revetment, managed retreat or do nothing.
The seawall would provide maximum protection of the road and utilities and cost $3.4 million to $4.1 million, according to Public Works. Installing a wall also would have a low impact on marine life, and minimize the coastal footprint and impact on coastal processes.
The rock revetment is estimated to cost $3.4 million to $6 million and offers the same protection as the seawall, while minimizing reflection. The revetment, though, would require a wider footprint.
A managed retreat inland would require a feasibility study because it could cost the county anywhere from $20 million to $25 million to purchase and condemn private lands. Utilities would need to be moved, and residents on Puamana Place would need to find a different entry way.
If the county were to do nothing, the lower road would likely be reduced to a one-lane road and eventually convert into a pedestrian and bike road, Ono said. Other roads would be closed, and the county would need to conduct a traffic impact analysis.
Jim Barry, coastal engineering for Sea Engineering, told residents that the 30-foot section is the most critical area that needs to be protected within Kaopala Bay. The northern part of the bay is already protected by rock, but “it’s not in very good shape,” he said.
Barry noted that the bay has a fairly high elevation, which is key for building a solid rock wall foundation. He said a rock revetment also could work due to its adaptability and being “pretty much bomb-proof if designed right.”
“It’s up for discussion how much you want to do here,” Barry told the crowd. “Ideally, you’d do the whole bay, or you can do the critical area and let the revetment be what it is, but my opinion is it’s not going to protect that bank for very long.”
Napili resident Tamara Paltin said she was against any seawalls and suggested the county start relocating its utilities under Lower Honoapiilani Road. Paltin, who lived on the road years ago, recalled a similarly large flood in 2003 that blew out the road, partly due to the underground culvert being overwhelmed.
“The storms are getting worse and more frequent,” she said. “The sewage line busting and flowing into the ocean and all those residents without water or sewer — that’s a huge catastrophe that we should have the foresight to plan for.”
Kahana resident Doug Pitzer asked the county to investigate water flow mauka from the road to alleviate pressure during large floods. During Tropical Storm Olivia, his home was nearly flooded when knee-deep waters rushed alongside his property through a drainage ditch.
“Keep it rural, no seawalls and a good temporary fix,” he said.
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* Chris Sugidono can be reached at firstname.lastname@example.org.