Could perfect storm of high tides, rain, rising sea levels bring unprecedented flooding?

Climate change and sea-level rise are often talked about in terms of a slowly building problem many decades in the future. But as Always Investigating shows, Hawaii is getting hit right now with severe high-water events, and more are on the way.

Sea-level rise itself is a gradual trajectory, but add in a recent Pacific-wide high water seesaw, extreme tides, and big swells, and we’re already getting frequent and consistent flooding in more areas than ever before. We wanted to know what’s being done to protect coastal infrastructure today, and to plan for a rising-water future.

Last week Friday, high water swamped areas across the islands, including in Waikiki where it breached far beyond the usual shoreline. It reached levels that can wreak havoc in business and residential areas.

It wasn’t a tsunami or a storm, but something becoming a new norm.

“It’s very hard for people,” said Jeremy Booth, who sees the change day in and day out working for Waikiki Shore Beach Service near the Outrigger Reef Hotel. “Just yesterday, I saw a couple, the water came up on them and they weren’t ready for it, and I think the guy lost his phone.”

“It affects the bikers, the people that walk the bike path. I mean they can’t use it obviously, everything backs up,” said Rory Chandler, who owns Central Body & Paint in the Waimalu area, a district that’s just recently seen big surges and flooding. “It affects the community here.”

What’s going on? Matthew Widlansky of the University of Hawaii Sea Level Center explains: “We’re seeing from the tide gauges as well as from satellite observations very high water levels around Hawaii. They’ve been persisting since the end of the last El Nino that ended in 2016.”

There’s more, like we got a taste of last week.

“On top of that, we had large tides, so we had a big high tide, high relative water levels, and then we had a high swell event,” Widlansky said, “and then on top of all of these conditions, we have the gradual rising sea levels with warming oceans and melting land ice.”

Always Investigating heard from residents and businesses seeing some serious flood problems they say have just popped up or worsened recently, especially at high tide.

Flooding in Waimalu at high tide

“It comes up from the manhole right there,” Chandler explained of now-frequent flooding near his Waimalu shop. “Customers driving in and out get affected. Their cars get wet. We’re next to the harbor so we’re not too sure if it’s salty brackish water. We do have a pump that just pumps it over the other side so we can do business during those occasions.”

At Sand Island near La Mariana and the HC&D plant, the flood waters come straight from the lagoon.

“They seem to be happening more frequently,” Widlansky explained of the tidal flooding events, “and the state of the science is telling us this is very likely to become more and more frequent of an occurrence and likely to be more severe as well. Definitely a critical need to pinpoint which areas of the coast are most vulnerable.”

“This kind of gives you a little glimpse or a look into our crystal ball of what the future might hold in terms of accelerating sea level,” said Sam Lemmo of the Department of Land and Natural Resources, who also heads the Interagency Climate Adaptation Committee, which is a public sector group to coordinate state and county climate adaptation.

Always Investigating asked, as people and businesses start to see specific problems around the islands, what do they do, how do they report it, and what happens next as you build an infrastructure list?

“The problem is sneaking up on us,” Lemmo said. “It’s a complicated, wicked sort of problem we’re all trying to struggle with. So in the meantime, I think people need to take remedial actions to address this. When I say remedial actions, I mean calling the appropriate entities, agencies, experts, and asking them for advice on what to do so we can figure out how to get ourselves through these types of events.”

Coastal erosion caused this portion of Kamehameha Highway to crumble in Windward Oahu, prompting the state to install a temporary fix. (Read More)

Meanwhile his committee is working on a report due at year-end that gets a bead on the sea-level rise situation and what to do.

“That might mean raising or elevating structures or moving structures away from vulnerable areas,” Lemmo said, “but then that involves a lot of other issues because our coastal areas are very densely populated and very highly and intensely used.”

That’s longer term. What about right now?

“Oh yes, there are plenty of hot spots. Honoapiilani Highway and going out to West Maui is routinely inundated by high waves and high tides,” Lemmo said. “The Department of Transportation is constantly having to do repairs to the highway. They have begun to look prospectively toward moving the road entirely away from these areas.”

There’s the erosion in Windward Oahu along a stretch of Kamehameha Highway.

“We go and repair it. We use concrete and we put more rocks in place, and we salvage the situation for the time being, but there’s this long-term creep that we need to address,” Lemmo said.

Waikiki Beach is ground zero for the economic risk and the extent of infrastructure exposed. We asked Booth what he sees now when it hits high tide.

“A lot of water. It goes far up past the sidewalks over here,” Booth said, pointing to the walkway behind the Army museum. “The Hale Koa Hotel does scrape the sidewalks every morning that it’s needed. With the high tide now, they’ve been coming every day because there’s like two, three, four inches of sand on the sidewalks already.”

“One of the ways you can deal with the problem of sea-level rise in Waikiki is to continue to maintain the beach,” Lemmo said of the action plan for that area. “If we continue to renourish the beach and basically maintain the engineered structures in Waikiki at a level that is sea-level rise resilient, then we can actually protect the backshore areas as well, so we can kill two birds with one stone.”

Knowing what’s coming is tricky, though. The old reliable models like tide calendars that used to predict spot-on years in advance are off-kilter lately.

“Currently we’re seeing higher-than-normal tide levels, very much higher in fact, as much as 10 inches over normal, predicted tides which is troubling,” Lemmo said.

Widlansky explains why just referencing a tide chart won’t suffice anymore: “They don’t capture the relative sea level changes that happen with climate fluctuations. Last week the offset between the tide prediction and what was observed at the tide gauges was about 25 centimeters. That was one of the largest offsets we would see in Hawaii outside of a major storm.”

This graphic is a simulation of what Oahu’s shoreline could look like at a) current conditions and b) 0.32, c) 0.60, and d) 0.98 m increases in sea level. (Courtesy S. 132 Habel et al. / Water Research 114 2017)

Consider last Friday a warm-up and mark your calendars: A potential battering is ahead in just a few weeks, what they call king tides.

“King tides are very large tidal cycles,” Widlansky said. “Even larger tides are in store for the end of May and then again in June and July.”

High relative water levels are also sticking around awhile. “It is predicted to continue throughout the summer, and that on top of even higher tides could set the stage for more coastal flooding, especially if they coincide with high swell,” Widlansky said.

Always Investigating asked, after making it through this difficult summer, does it then ebb just as much or is this the new normal?

“That’s something that we’re researching now. We know the sea level ebbs, or swashes — seesaws across the Pacific,” Widlansky said. “But we do know over the long term, sea levels are continuing to gradually rise. That gradual rise in sea level is expected to cause nuisance flood events to become more severe but also more frequent.”

UH has done extensive studies and ongoing looks at sea level and rising ground water problems too. The Sea Grant program has collected hundreds of photos from across the state documenting water rise hot spots. They want to see yours too, and so do we. Be on the lookout, but be safe during the extreme tides later this month and through the summer, and send us and the Sea Grant program your photos and videos.

Submit your photos to KHON2 via Report It here and the UH Sea Grant Hawaii King Tides project here.

Click for 6-day high sea level forecast for: Honolulu | Nawiliwili | Kahului | Kawaihae | Hilo

Click for wave run-up forecast for: Waikiki | North Shore (The wave run-up forecast also takes wind-generated swells, waves into consideration.)

Access the UH Sea Level Center monthly forecast tool

UH study of ground-water inundation induced by sea level rise: Summary | Full Study (.pdf)

Honolulu

City and County of Honolulu spokesperson:

“In addition to advocating for passage of a Charter Amendment that created the Office of Climate Change, Sustainability, and Resiliency, the administration has been engaged in both short-term and long-term planning for the effects of climate change.

We are incorporating consideration of sea level rise, resilience, green infrastructure, and climate adaptation into several TOD projects in the Iwilei/Kapalama area. See attached project fact sheet for the Iwilei-Kapalama infrastructure master plan and finance district.

We’re also working with major landowners (including several state agencies) to determine infrastructure and street network needs to support mixed-use redevelopment, as well as affordable and workforce housing.

That plan wraps around the Kapalama Canal Catalytic Project, which is designing a linear park and gathering space along the canal between Nimitz Highway and H-1. Honolulu also won technical assistance from EPA’s Greening America’s Communities program, which is providing an expert consultant team to develop conceptual designs for five (5) sites in the Iwilei-Kapalama area, including green streets/infrastructure and climate adaptation strategies. We have scheduled a design charrette for that project for July 12-14, with a public meeting Wednesday evening July 12 (time and location TBD).

The city is also starting to address similar issues in other TOD areas, and the lessons learned from this effort can be applied to other parts of Oahu.

Elsewhere, the State-sponsored (with US Army Corps of Engineers) Ala Wai Flood Risk Management Project just received the Corps’ Civil Works Review Board approval to request Congressional funding.

Also, the city (mostly Department of Facility Maintenance) is performing over $10 million of National Pollutant Discharge Elimination System (NPDES) storm water management projects that indirectly protect against sea level rise. (Search for “NPDES” on the mayor’s proposed CIP budget for FY-2018, to see the projects the administration proposed.)

Additionally, cabinet members and department staff have been briefed on the threats posed by climate change by experts with the University of Hawaii Sea Grant Program, while also attending various workshops. Sea Grant sea level rise modeling is helping the city address areas of concern for future mitigative projects.

As for the Office of Climate Change, Sustainability, and Resiliency, Chief Resilience Officer Joshua Stanbro will conduct a study to model the effects of sea-level rise along Oahu’s coastline.”

Department of Environmental Services spokesperson:

“We are now including the consideration of sea level rise, changes in ground water conditions, and other associated potential impacts in all our wastewater long-range planning. Many of our facilities including treatment plants, pump stations and conveyance systems are in areas that clearly have the potential to be impacted. An example is the Sand Island Wastewater Treatment Plant where we are including these issues in our upgrade planning and design. This is and will continue to be important to our facility planning.”

Maui County

Maui County UH Sea Grant specialist and county environmental coordinator:

There are so many examples of erosion impacts, especially over the last two winters. West Maui has been particularly affected. We have several areas where 10-12 story condos/resorts (Kahana, North Kaanapali) are within feet of the ocean.

In these cases, chronic erosion from sea level rise has led to a point where the beach is narrow and can no longer provide natural buffer to seasonal large waves. And our main transit corridor to West Maui — Honoapiilani Highway — is extremely vulnerable to erosion and wave runup now and into the future. Our community has been very active trying to avoid further admiring of the highway in favor of relocation. Another erosion hotspot in South Maui that seems to have been really affected by the recent high tides is Halama Street.

There is so much good work being done by so many folks. The coastal zone management planners in each county, and planners at DLNR OCCL, are on the front lines of these issues. We are also thinking ahead. We have staff working on the statewide SLR Adaptation led by DLNR. And, in terms of implementing adaptation measures, one way to be proactive is through pre-disaster planning and our Maui CZM team has been focusing on this area to develop post-disaster rebuilding guidelines.

Maui successfully passed a ballot measure in 2012, with two thirds of voters asking the include Environmental Protection and Sustainability in the powers, duties and functions” of the Director of the Department of Environmental Management.

Kauai County

Kauai County spokesperson:

“Like the other islands, Kauai has been experiencing long term, chronic shoreline erosion for years. Also flooding, wave inundation, etc, and sea level rise is a contributing factor.

With respect to long term planning, the draft Kauai County 2035 General Plan (GP) update incorporates climate change and sea level rise considerations in various chapters. Sea level rise mapping influenced the land use map. There are also several policies and actions directing further study and planning efforts once better scientific information that documents the impacts on the ground becomes available. For example, the state Interagency Committee on Climate Adaptation (ICAC) is working with researchers at UH to map erosion and wave inundation impacts from sea level rise. Once that type of information becomes available, the counties will be much better equipped to plan and make decisions about infrastructure that will be in harm’s way. The draft GP also points to actions suggesting the need to conduct Hazard, Risk and Vulnerability Assessments on a community scale to inform future adaptation efforts.

Additionally, a few years ago the county adopted what is probably one of the most progressive shoreline setback requirements in the nation that are based on annual erosion rates as determined by the University of Hawaii Coastal Geology Group.

As for the areas that fall under the county’s jurisdiction that need protection and remediation, the Planning Department works closely with other departments, providing them with the latest information on the impacts of climate change and sea level rise. The projects that Kauai County is currently focusing on include:

  • Aliomanu Road, Anahola – installation of a revetment, project underway
  • Pono Kai and Moana Kai seawall, Kapa‘a – Repair work on the seawalls were completed last year. A sand nourishment program is ongoing for Pono Kai.
  • Salt Pond area, Hanapēpē – Plans are underway for an RFI to be issued for a hydrological study to examine the cause(s) of the increased flooding in in recent years.”

Hawaii County

Excerpt from article by Ali Andrews, Tetra Tech, based on an interview with Bethany Morrison, Hawaii County Planning Department. (October 16, 2015):

One of the challenges Hawaii County discusses at ORMP [state Ocean Resources Management Plan] and faces in adaptation is identifying and quantifying the impacts of sea level rise. Hawaii Island’s coastline is expansive and unique among the state – mostly basalt rock as opposed to sandy beach – which give it unique hazards. “Other counties use erosion rates for their shoreline setbacks but we don’t have any erosion rates so our shoreline setback does not account for physical shoreline changes on the property,” said Morrison.

To address this dearth of data, the Planning Department collaborated with University of Hawaii Hilo to collect available Geographic Information System (GIS) data on coastal hazards and apply it to the shoreline to see which areas are vulnerable to which hazards. “It didn’t really give us any new information but it confirmed that low lying areas are the most vulnerable, which is something we have seen from working on the ground in these communities. We still need to understand how vulnerable they are and what measures might need to be taken to protect them.”

Having studies to inform action, Morrison explained, is crucial to implementing good policy. For example, a study was conducted in Kapoho, in the district of Puna, on the eastern tip of Hawai’i Island, to determine the rate of subsidence – a geologic phenomenon where the land gradually sinks in elevation. “We have been able to successfully use that subsidence rate to increase the base flood elevation requirements for some structures being built in the Special Management Area (SMA).”

The lesson from this, Morrison explained, is that sea level rise can be treated much in the same way that subsidence in coastal areas within Special Management Areas (SMA), which are areas near the coast containing valuable natural resources that are protected by additional regulations and permits. Established in 1975 under the Coastal Zone Management (CZM) Program, SMAs include all areas within 500 feet of the shoreline statewide, with additional natural resource areas farther from the coast as outlined by individual counties. SMA Permits are issued by counties to regulate appropriate land use.

“The SMA has been a good tool. It allows for a little more dialogue,” said Bethany of using SMA permits to require coastal development to consider coastal hazards in their plan. “Because otherwise if [landowners] meet the code requirements, they can develop, but in the SMA we can mitigate for any impacts.”

“Sea level rise as a coastal hazard is one of many,” Morrison said, which means that it can be treated as other coastal hazards such as subsidence. By using existing regulatory frameworks such as the SMA, Hawaii County could require coastal development to factor in sea level rise alongside other coastal hazards. In order to employ this useful tool, Hawaii County’s next step will need to be acquiring island-specific data on how sea level rise will impact the coastline.

Hawaiian Electric

Peter Rosegg, HECO Corporate Relations:

“The threat of tsunami has long been recognized so shoreline power plants are designed with critical equipment elevated. In addition, Waiau Power Plant is protected by location within Pearl Harbor. We do not recall a high tide issue at either Waiau or Kahe. Honolulu Power Plant had some minor issues in the past and is now closed.

Our main concern at all times, including tsunami and high tides, is that intake and discharge of cooling seawater works. Higher than usual tides will require increased vigilance but, as yet, no special precautions.

Schofield Barracks generating station being built in central Oahu is located inland at elevation, away from coastal impacts from storms or tsunami. It will strengthen the Oahu grid for emergencies. Impacts of climate change are a consideration in future power supply planning.

Also, our companies’ ultimate goals are to reduce dependence on imported oil and climate-altering greenhouse gas (GHG) emissions, especially carbon dioxide.

  • From 2008 to 2016, Hawaiian Electric’s use of oil in generators on Oahu fell to 6 million barrels from 7.8 million barrels. For all three Hawaiian Electric Companies, oil use fell to 8.5 million barrels from 10.7 million barrels, a 21 percent decrease.
  • The Hawaiian Electric Companies’ goal is to reduce GHG emissions to the 2010 level by 2020. In fact, it’s anticipated the companies will do better, reducing the 2020 level to 16 percent below the 2010 level. That would cut emissions by 865,000 tons per year. That is equivalent to any one of the following:
    • 1.8 million barrels of fuel per year
    • Emissions from 166,000 passenger car in a year.”

Hawaii’s Congressional Delegation

Spokesperson for Sen. Brian Schatz:

“I am pleased to report that on the whole, we held steady on the funding for these activities in the spending deal that just passed the Senate today. Knowing and understanding the changes to the sea level helps keep maritime navigation safe, and allows coastal communities to plan for hazards such as flooding and erosion.” – Sen. Brian Schatz

“NOAA observes and monitors ocean levels, tides, and currents, and other factors to keep coastal communities safe and prosperous. Sen. Schatz worked to include funding for these important services at NOAA in the Fiscal Year 2017 Omnibus, and in some cases, helped to secure modest gains. For example, he was able to increase funding for the Integrated Ocean Observing System (IOOS) from $29.5 million to $30.7 million. This money helps to fund the University of Hawaii’s Pacific Integrated Ocean Observing System (PacIOOS) to help support forecasts of storm events, high waves, and extreme tides up to six days in advance.”

Spokesperson for Rep. Colleen Hanabusa:

“The starting point at the federal level is to understand that the majority of the House Republican Caucus are climate change deniers. The percentage is 59% right now. What that means is that you have to convince the majority that the problem is real and it can be challenging, if not impossible.

Rep. Hanabusa sits on the House Armed Services Committee (HASC), Natural Resources Committee and Science Space and Technology Committee and each of these committees struggle with climate change issues. HASC, one of the more bipartisan committees in Congress, is probably the most likely to deal with base climate change issues since many of our nation’s 1,200+ military installations are located in coastal regions in the US and are experiencing climate change issues (like Norfolk as one example).

Just like a coastal city, military bases along the coast experience flooding of streets, sewer and water infrastructure issues, seawall/pier face challenges and coastal erosion. Since military readiness is a priority, it is often easier to get appropriations for these type of issues through HASC versus deal with them in Natural Resources and Science, where, frankly, they challenge the basic concept of climate change and the data gathered by scientists.

As Congresswoman who believes in climate change and taking proactive steps to make our nation’s infrastructure resilient, it means Rep. Hanabusa has to fight for the appropriations necessary to implement real solutions to disputed problems. As one example, she most recently reworked her scheduled so she could personally appear before the Army Corps Civil Works Review Board to advocate for the Ala Wai Canal Project which is a major infrastructure resiliency project designed to protect Waikiki and the Moiliilii drainage areas. The Board voted unanimously to advance the project.

It’s about being vocal, persistent, insistent and determined. Rep. Hanabusa most recently signed a letter to the Speaker and House Budget Chair calling for $1 trillion in infrastructure appropriations.”

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s