Lanikai Beach, a picturesque stretch of sand on the southeastern coast of Oahu, Hawaii, is facing a critical issue – erosion. This once-pristine beach is slowly disappearing, and the impact on the local community and the environment is becoming increasingly concerning.
The Alarming Erosion Rate
The erosion rate near Wailea Point, close to Lanikai Beach, is approximately 9 feet per year. This rapid loss of beach area is a stark reminder of the urgent need to address the underlying causes and find sustainable solutions.
Causes of Erosion: Seawalls and Sea Level Rise
The primary drivers of erosion on Lanikai Beach are twofold: the installation of seawalls by property owners and the natural migration of the beach due to sea level rise.
Seawalls: Disrupting the Natural Beach Cycle
Since the 1970s, property owners have installed seawalls to protect their homes from the encroaching waves. While this may have provided short-term protection, it has had a detrimental effect on the beach itself. These seawalls have disrupted the natural process of beach migration, leading to accelerated erosion and the loss of half the beach over the past few decades.
Sea Level Rise: A Looming Threat
Scientists predict that by mid-century, Oahu could lose 40% of its beaches due to a projected 3.2-foot rise in sea level by 2060. This rise in sea level will increase the intensity of impacts from storms and high waves, further exacerbating the erosion problem.
The Impact: Vanishing Beaches and Public Access
The erosion of Lanikai Beach has had a significant impact on the local community and the environment. The installation of seawalls has resulted in the loss of public access to the beach, leaving only a narrow walkway for beachgoers. This has raised concerns among residents about the diminishing recreational opportunities and the hazardous conditions created by the seawalls during high swells.
Efforts to Address the Issue
Pilot Restoration Project
The U.S. Army Corps of Engineers has designed a pilot beach restoration project for the southern Lanikai shoreline. This project includes beach nourishment with and without structures, aiming to create a 30-foot wide beach crest. The project requires 22,100 cubic yards of sand at an estimated cost of $4,750,000.
Soft Approach to Shoreline Protection
Experts recommend adopting “soft” approaches to shoreline protection, such as restoring sand dunes, instead of hard structures like seawalls. This approach can protect homes while preserving beaches and their ecosystem services.
Legislative Efforts
Hawaii has introduced legislation, such as SB 2060, to strengthen prohibitions against coastal hardening and increase the building setback for new development to 40 feet. This aims to protect natural infrastructure like reefs, beaches, and dunes that inherently protect against coastal hazards.
Community Involvement and Advocacy
Local residents are actively involved in addressing the erosion issue at Lanikai Beach. They are advocating for the county to reopen public corridors and reconsider the approval of new seawalls, which have contributed to the loss of the beach.
Conclusion
The erosion of Lanikai Beach is a complex issue that requires a multifaceted approach. By addressing the underlying causes, implementing sustainable management practices, and engaging the local community, there is hope for preserving this iconic Hawaiian beach for generations to come.
References:
– Confronting Shoreline Erosion on O’ahu. (2024). Toolkit Climate.gov. Retrieved from https://toolkit.climate.gov/case-studies/confronting-shoreline-erosion-o%E2%80%98ahu
– Lanikai Beach Restoration Pilot Project. (n.d.). U.S. Army Corps of Engineers. Retrieved from https://rsm.usace.army.mil/hawaii/M2M_lbrpp.htm
– Officials Let Hawaii’s Waterfront Homeowners Damage Public Beaches. (2020). ProPublica. Retrieved from https://www.propublica.org/article/officials-let-hawaiis-waterfront-homeowners-damage-public-beaches-again-and-again
– Going, Going, Almost Gone. (n.d.). Climate Change Portal. Retrieved from https://climate.hawaii.gov/hi-news/hi-blog/hawaii-beaches/