Nine condominiums and one residential lot are collaboratively investigating long-term, regional solutions to extreme beach erosion at Kahana Bay on Maui. Representatives from each of these properties formed the Kahana Bay Steering Committee (KBSC) and contracted Oceanit to study alternatives, recommend a Proposed Action, and study the impacts of this action in a Draft Environmental Impact Statement (DEIS). Oceanit worked with other specialists to prepare deliverables, collaborate with the community, and conduct the studies required for the project to proceed to construction.
Kahana Bay is currently at an inflection point for mitigating natural hazard risks to public safety and developed infrastructure. For decades, sea level rise (SLR), strong wave action, coastal flooding, and shoreline development have transported sand and soils away from the Kahana coast. This chronic and episodic coastal erosion has resulted in shoreline recession; beach narrowing and loss of sandy beach area and sand dunes; a reduction in public access; and increased risk of natural hazards to the community, oceanfront resources, buildings, infrastructure, and amenities.
In response to the increased coastal flooding individual properties have, over the years, installed a variety of shoreline protection structures, ranging from stone and concrete seawalls to vegetated sand berms and temporary sandbag revetments. Aging structures that may not have been originally designed with the intention of providing coastal protection have been modified to accommodate wave forces.
The Maui County Planning Department, SeaGrant, KBSC, and Oceanit have come together to find ways to manage coastal resources for generations to come. To protect the coastline, community, and public safety, it became apparent that a better way to address regional coastal erosion was through a community-driven approach, engaging many stakeholders across the properties, community, and nearby areas. The inclusion of environmental, cultural, ocean users, and community stakeholders in the EIS process was of high importance.
The overall purpose of the project is to develop a sustainable and resilient approach to regional erosion along the Kahana shoreline, including efforts to:
- Explore, develop, and encourage a cost-effective, regional erosion mitigation solution for the Kahana shoreline that will minimize impacts to the sensitive coastal environment and enhance nearshore habitat while protecting existing habitable structures;
- Restore and preserve the sandy beach and offshore resources for cultural, social, and recreational uses, including ocean sports, food gathering, and passive enjoyment;
- Encourage shoreline protection that is compatible with natural and existing site conditions;
- Establish a design based on accepted engineering principles and best management practices (BMPs);
- Propose a project that is compatible and consistent with Federal, State, and County regulations, policies, and plans; and
- Develop a sustainable and resilient solution that withstands projected SLR while minimizing environmental impacts of required maintenance.
Link to the full Draft Environmental Impact Statement on the Hawaii Office of Environmental Quality Control website: https://files.hawaii.gov/dbedt/erp/EA_EIS_Library/2021-11-08-MA-2nd-DEIS-Kahana-Bay-Erosion-Mitigation.pdf
The Environmental Bulletin also features this DEIS on page three of this document: https://files.hawaii.gov/dbedt/erp/The_Environmental_Notice/2021-11-08-TEN.pdf
Click the links below for summaries and quick information about various parts of the Kahana Bay DEIS: