Dolan Eversole: Coastal geologist helps find solutions to preserving Waikiki Beach

Beach erosion, near-shore water quality, protection of surf sites and public safety are surfacing as top concerns in the fledgling Waikiki Beach Management Plan, called Ho‘omau ‘O Waikiki Kahakai (Waikiki Renews Itself), which aims to serve as a guide in the shoreline community’s effort to chart its future.

Earlier this month, the Waikiki Beach Community Advisory Committee, which oversees the Waikiki Beach Special District Improvement Association (WBSIDA), held the first in a series of meetings that offer the public a chance to weigh in with project and funding ideas.

“The community voice is very important right now and will help shape the vision for what Waikiki will look like in 30 to 50 years,” said WBSIDA’s coordinator Dolan Eversole, a coastal geologist at the University of Hawaii’s Sea Grant Program.

“Every person I speak to about Waikiki has a strong opinion and is willing to share their ideas and mana‘o on solutions,” he said. “While everyone is not always in agreement about what to do, everyone has a passion for protecting and improving some part of the beach, its history and culture.”

Commercial property owners in the special district, created by city ordinance in 2015, pay annual tax to the public-private partnership, with that revenue tagged for various beach upgrades and related surveys and maintenance. The district stretches from Ala Wai Harbor to Kaimana Beach and mauka to the Ala Wai Canal.

Eversole is a San Diego native who moved to Hawaii 25 years ago to study geology at UH-Manoa, prompted by his passion for the “physical processes of the natural world and environment.” During his high school and college years, he worked as an ocean lifeguard. “Growing up around the ocean and ocean sports led to a clear path to Hawaii for me,” he said.

As the beach management plan takes shape, Eversole said, its framers must strive to base decision-making on “interdependent relationships” intertwining the environmental with an economic, social and cultural ecosystem tied to reef and water quality rather than responding to “crisis after crisis of beach erosion with ad hock erosion projects.”

Also, amid climate change projections, he said, “We are going to need to think differently on how to not only solve the problems we are experiencing but … to plan for the future based on the science and practical and social-economic elements of maintaining a beach in a place like Waikiki.”

Question: In the absence of a concerted effort to fend off erosion, how quickly would Waikiki Beach disappear?

Answer: The short answer is about 10 to 15 years, depending on what part of Waikiki you’re in. Based on historical data (including aerial photographs) … the Waikiki shoreline is highly variable but generally exhibits an annual average shoreline change rate of about -1 foot/year as a whole where there have not been regular additions of beach sand.

Without past beach nourishment efforts, which date back to the early 1900s, there would be no beach in Waikiki at all.

Q: So far, what’s the most challenging aspect of the coordinator’s post with the Special District Improvement Association?

A: Probably working at the beach when the waves are really good. As a surfer, it is difficult to watch the waves go off while I’m working on the beach. Beyond this simple personal issue, however, I’d say … working within a complex regulatory environment where it takes time to get projects done.

Anytime you do any work along the shoreline it triggers a review process that can sometimes take years to get through. Meanwhile the shoreline continues to erode and many stakeholders don’t understand what the delay is. Actively managing shoreline projects and people’s expectations of what can be done quickly takes a lot of patience and understanding of the overlapping regulatory jurisdictions, each with their own independent time frames.

Q: What’s the timeline for completion of the master plan?

A: The initial draft will be completed by this summer, but we envision this to be a “living document” that will go through regular updates. The management plan will identify and prioritize efforts for further development through a separate coastal engineering study the state Department of Land and Natural Resources (DLNR) is leading.

The management plan will include key partnerships with DLNR and the City and County of Honolulu as the two primary government agencies, with regulatory and management authority in Waikiki. Most major improvement projects on the beach will likely be a public-private partnership with the WBSIDA and DLNR and/or city.

Public-private partnerships with the ability to share costs and help manage projects with the state and city is exactly why the WBSIDA was set up in the first place.

Q: The improvement association is pitching in for replacement of the Royal Hawaiian groin with the proposed T-head structure?

A: The WBSIDA has agreed to pay up to $750,000 as a cost share, which is currently estimated to be 50 percent of the total $1.5 million project cost. This project is still going through the regulatory permit process and is expected to be ready for construction in about one year. The project scope is to replace the existing groin with a new T-head rock groin that will serve to stabilize the beach and help to prevent severe erosion of Waikiki Beach in the event the existing, 90-year-old wall fails.

This project does not currently include any additional beach sand. So, the project intent is to increase the stability of the existing beach by reducing the seasonal fluctuations in the area rather than increase the size of the existing beach.

Q: In the aftermath of the beach replenishment project DLNR completed about five years ago, a UH study found that one-fourth of replenished sand was gone a year after its completion. Why did the replenishment unravel so quickly?

A: The 2012 Waikiki Beach maintenance project has lasted pretty much as expected. … Until the Waikiki beach sediment system is stabilized, it will require regular and frequent additions of sand to keep up with the accelerating rates of erosion.

It is also important to understand the “sediment system” includes the dry beach but also extends into the water to a depth determined by the waves and the reef.

Because the beach system extends into the water, beach restoration projects typically include an additional 25 percent or so as an “overfill” to the desired design goal, knowing there is often an immediate rapid loss of newly placed beach sand into the near-shore. … The beach stabilizes after the initial beach equilibrium shift.

So, the 25 percent loss of beach in the first year is actually expected as part of the design method and is a pretty common standard practice around the world. We can, of course, reduce this initial loss of sand if there are shoreline structures engineered or re-engineered to stabilize the beach system, such as new groins or reconfiguring the existing structures.

Q: If current sea-level rise projections hold, how long will it be possible to postpone a call for Waikiki to move to higher ground?

A: This is a tricky question since there is still lots of uncertainty about what the future holds for sea-level rise. We know that sea-level is rising and the rate of change is accelerating; this is certain. What the final rate will be depends on future emission scenarios so there is a bit of uncertainty around the exact amount to plan for. The current projections range from 1 foot to 6 feet of global mean sea-level rise by the year 2100. Our confidence in these projections is very high in the shorter-term projections (20 to 40 years), and goes down the further out you go.

Furthermore, it may be possible to hold off some of the initial effects of sea-level rise if we are willing to put resources toward that and even adapt by accommodating water in our communities rather than constantly fighting it. So, the direct answer to the question is: “It depends” on how much we are willing to invest in adapting to higher sea-levels and more erosion.

We follow what is happening elsewhere and there are many communities planning for a future of higher sea-level by technical- and engineering-based solutions like raising the elevation of the ground and by pumping down the groundwater table. This is not very efficient or sustainable, but will work at least in the short-term.