Draft environmental assessment details Māʻalaea condo plans for erosion control

Public comments are due Jan. 22 for a proposed installation of a “geotextile, sand-filled burrito” as erosion control at the Kanai A Nalu, a nearly 50-year-old, four-story condominium in Māʻalaea.

The erosion control measure would precede removal of existing, 1970s-era seawalls along the shoreline, which has a history of chronic and episodic erosion and lineup of multi-story condominiums on the South Maui waterfront and Hauoli Street. The approving agency is the Maui County Department of Planning.

The draft environmental assessment, posted today in state Office of Planning and Sustainable Development’s Environmental Notice, says that the Kanai A Nalu, located at 250 Hauoli St., and Maui County “have agreed to a series of actions to adapt to sea level rise, to restore more natural movement of the shoreline, and to re-establish native plants on the shoreline.”

The geotextile, sand-filled burrito would be moved back from the shoreline toward the condominium buildings.

“This soft structure will allow the condominium to negotiate a permit with the State of Hawaiʻi Office of Conservation and Coastal Lands for the removal of the existing seawalls, restoring an unarmored shoreline,” the draft environmental assessment says. “Kanai A Nalu also proposes a wooden ramp to allow for safe passage by the public to the beach. And lastly, restoration of native plants along the unarmored shoreline.”

The Māʻalaea shoreline faces southeast and is affected by south swell during the summer months and Kona storm waves in the winter and spring.

Proposed erosion-control actions by Kanai A Nalu include:

• Embedding a geotextile burrito into its lawn adjacent to the ocean. “The burrito is a soft erosion control response that will be comprised of one cubic yard sacks filled with in situ sand.”
• Removing remaining seawall segments at Kanai A Nalu, which has about 370 feet of shoreline.
• Restoring native plant dunes between the shore and the makai edge of the sand burrito.
• Providing the public and residents of Kanai A Nalu safe access to the beach by installing an inset wooden ramp along the eastern property boundary.

According to the draft environmental assessment, the construction of Māʻalaea Harbor in 1952 led to the loss of a 1,500-foot narrow beach to the east of the harbor. That erosion led to the construction of a series of seawalls and revetments that extend 2,400 feet east of Haycraft Park, which is managed by Maui County.

An evaluation of coastal erosion along the Kanai A Nalu shoreline by the University of Hawaiʻi Coastal Geology Group, using historical aerial photographs from 1900 to 1997, found that the beach fronting the condominium has been eroding at an average rate of a foot per year.

In 1997, Kanai A Nalu conducted beach restoration project to mitigate erosion and undermining of the seawalls. Sand replenishment of approximately 1,500 cubic yards took place three times from 1997 to 1998, according to the environmental assessment, but much of the sand was gone by 2001.

Kanai A Nalu conducted beach restoration again in 2003. That project consisted of the placement of 3,000 cubic yards of inland dune sand, the assessment says.

It says that Maui County has completed a sea-level rise resiliency study for the Māʻalaea region with the assistance of a qualified contractor. The contractor evaluated a number of mitigation tools, studying the pros and cons, potential for coastal hazard mitigation, construction and maintenance costs and regulatory constraints. A wide array of actions were evaluated including groins and nearshore breakwaters, beach nourishment and vegetated sand dunes, rock revetments, elevating existing structures and landward relocation of buildings.

The draft assessment says the contractor ultimately reported that:

The “tools” were evaluated individually and in combination, and “based on these assessments, the results of the Māʻalaea sand search and current state of regulations on shoreline structures, many of the tools were determined to be not currently feasible.”

“The analysis indicated that there are tools which can be used for shorter term or interim resiliency improvements, but that, ultimately, relocation may be required in the long term due to sea-level rise.”

Public comments can be sent via email to Coastal Resources planner James Buika at the Department of Planning at James.Buika@co.maui.hi.us.