Disaster response readied for ‘king tide’ flood risk

Earlier this month, Always Investigating revealed what’s causing havoc along some coastal areas as we saw in late April, and this week could be an encore — what they call “king tides” striking right alongside the Memorial Day weekend.

We first exposed how unexpected flooding statewide last month was traced back to unusual tides stacked on already higher sea levels. Now agencies from state civil defense to county emergency management, lifeguards, even hotels and others with coastal assets are on guard and gearing up for what could be significant flooding.

King tides are abnormally high-water events that even on their own could be a nuisance for coastal roads and buildings. But the tides are not alone. They’re stacking atop a pile of other things causing already higher sea levels: one is incremental sea rise, plus a Pacific-wide upwell hanging around since the last El Nino, plus eddies — currents caught in a swirl — that are pushing up, too.

“We are particularly worried about the upcoming king tide, because I think with that additional sea level on top of the king tides what potentially could push it over record levels this summer,” Merrifield said.

Now this Thursday and Friday, May 25 and 26, and likely beyond comes a king tide around 2.5 feet atop a south swell that could top 8-foot advisory levels.

“If we get a big southern swell on top of the eddy, on top of the Pacific decadal signal, we will go above the April event, considerably above it,” said Mark Merrifield with the University of Hawaii Joint Institute for Marine and Atmospheric Research.

The April event Merrifield is talking about occurred Friday evening, April 28, that Always Investigating covered as part of our story on rising sea levels, when tides washed out roads and beaches, breached sidewalks, and caused havoc for homes and businesses.

“That was the highest water level ever recorded for a day average, back to 1905,” Merrifield said, referring to the very start of tide gauge measuring in Hawaii.

Here’s what to watch out for as the next king tide rolls in.

“It’s of course not just Waikiki,” Merrifield said. “The whole south shore of Oahu, south shore of most islands will be facing the same sort of problems: high water levels, potentially high waves, beach erosion, and then overwash as these waves reach the shoreline. … The higher the water level, the higher the waves at the coast and many areas around the islands, and the more waves, the more rip current there will be, so potentially strong rip currents during the peak of the tide.”

In June, the next king tide is expected to be even higher, June 23-24, and then another one comes July 21-22.

“The message is this is going to be quite higher than what we typically experience,” said Matthew Gonser of the UH Sea Grant Program. “June is actually forecast to be the highest tide prediction, so potentially these other things could stack up to contribute to the water level.”

Sea-level rise forecast tools:

It’s a risk big enough to get the attention of officials who usually watch things like hurricanes and tsunamis. The head of state emergency management held all-hands-on-deck coordination across state, county and federal agencies last Friday in advance of the tides.

Full statements from state and county agencies can be found at the bottom of this post.

“We are standing by with the appropriate resources to support it as it gets higher and higher,” said Vern Miyagi, Hawaii Emergency Management Agency administrator.

Always Investigating asked, what of impacts does Hawaii EMA think high tides like this could have? What hazards are they looking for?

“This is all flooding,” Miyagi said. “This is a not a flash flood. This is a low-rising flood.”

Miyagi says the public should gear up as they would for any forewarned weather event.

“When you look at floods and critical infrastructure, what can you do? There are only two things you can do and that’s move it or protect it. That’s all you can do right now,” Miyagi said. “Get an idea ahead of time. Do I evacuate my important material out of my structures or do I try to protect it? This is the sandbags and all that diversion kind of stuff, but that’s all we can do at this point in time.”

Always Investigating asked, between all of the civil defense agencies, what coastal infrastructure can they realistically protect, and what will they focus on the most this coming week and through the summer?

“I think for our standpoint, it’s really the critical infrastructure, the power plants, the sewage treatment plants,” Miyagi said. “City and County (of Honolulu) has the sewage treatment plants on Sand Island. Then DLNR (Hawaii Department of Land and Natural Resources) and Department of Transportation are going to be very affected with the sea coast roads and making those clear, and sea coast erosion that has happened in the past.”

Hawaii’s busiest tourist district is also gearing up for the king tides.

“For (Waikiki hotels), this is an issue, but they’re ready for it,” said Rick Egged of the Waikiki Improvement Association. “They’re making sure that they’ve got sandbags prepared. It’s not just the surf, it’s the groundwater. As you’re getting all that pressure, the groundwater comes up as well, so threatened are the underground support areas in the hotel, underground parking garages.”

Visitors are likely to get a heads up about staying safe in the water, too.

“We are running operations as usual but we will be informing lifeguards of the situation,” the city Ocean Safety and Lifeguard Services Division said in a statement.

“Oftentimes they will alert their guests if there is a situation such as that. Usually they work very closely with the ocean safety people,” Egged said of area lifeguards, “and they stay right on top of this situation.”

In that April 28th tide, the Friday fireworks over Waikiki were called off when the beach staging area became awash. Hilton Hawaiian Village says it intends to launch fireworks this Friday, May 26, by taking extra measures to safely stage the show:

“Although a higher than normal tide is anticipated this Friday afternoon, the Hilton Hawaiian Village’s fireworks display is scheduled to go on at 7:45 p.m.  Extra measures will be taken to safely stage the fireworks in their normal location on Duke Kahanamoku Beach.  The same precautions will likely be taken for high tides anticipated in June and July.”

Civil defense agencies say hurricane season, along with king tides, could bring a double whammy.

“June 1 is the hurricane season start, so this has to be put together with that hazard,” Miyagi said. “We’re going to have to have some input there about these high tides’ significance. The support from us is really the state agencies, state assets, and if it gets high enough to declare a presidential emergency or disaster, then we can go to FEMA and the federal side.”

Always Investigating asked Miyagi if he thinks tides could cause that kind of damage.

“I don’t know. The Maui flood last year for example, we tracked two hurricanes that missed the islands, and then there was that rain storm that stayed over Iao Valley, and it just stayed there, no name, no designation as a hurricane or anything, but it flooded out Maui. That became a presidential declaration,” Miyagi said of the damage flooding can do.

Always Investigating asked of the coastal visitor, residential and business industries, does the worry grow through the summer as hurricane season arrives alongside king tides?

“No question,” Egged said. “These high tides are something that are unusual. We have not experienced these before, but we have been prepared for these kinds of events before. No question we have a whole protocol involved with dealing with hurricane season as it comes. We work very closely with civil defense and we will be ready.”

The University of Hawaii wants your help to observe and report back on the impact of king tides statewide. It’s gathering photos in a citizen-scientist project, and has hundreds of new data points from it already. UH wants more this week, June, and July, and is asking the public to keep an eye and a camera out — safely — to help document the king tide onslaught.

King Tides Project: Website | Map Viewer | Current Submissions | Data Collection App for iPhone and Android

“There are certainly areas of our coastline we have not documented,” Gonser said. “To get more coverage around the state would be important to get a better sense of what these impacts could be in the future. This really provides us an image of what the baseline condition could be in the future with sea-level rise. You could imagine some combination of a future where we’ve increased by one foot, but you still have the tidal variation, or we’ve increased by three feet and that’s our baseline.”

Always Investigating will be on guard this week as the tides roll in, keeping an eye out for any flooding. Also with the south swell coming in, our KHON2 weather team will be keeping you up to date on the surf and ocean forecast.

Stay with KHON2 for the very latest updates on the king tide phenomenon.


Hawaii Emergency Management Agency

What is Hawaii EMA doing to protect coastal infrastructure during the anticipated “King Tides” periods?

Emergency managers in all counties are concerned about tropical cyclones (storms or hurricanes) that may hit during the “King Tides” periods. This would greatly magnify the destructive flooding effects of these hazards. The 2017 hurricane season begins on June 1, 2017. HI-EMA will continue close coordination with the county emergency managers, affected state departments, and the National Weather Service (NWS) during this period. As a note, the NWS will issue their 2017 hurricane season forecast at a briefing on May 24, 2017.

At the request of the affected counties or state departments, and upon the appropriate declarations, HI-EMA would coordinate state, federal, military and other support to the counties and departments. Anticipated support would include: public awareness and outreach; evacuation; damage assessments; and repair/restoration of critical infrastructure and key resources.

What is Hawaii EMA doing to protect coastal infrastructure today and in the future?

Our primary mission at HI-EMA is to protect the people of Hawaii from disasters and emergencies. To accomplish this mission, we provide direct support to the counties. Under HRS 127A, the counties lead the emergency preparation, response, and recovery operations in their jurisdictions and we at the state level coordinate state, federal, military, private, and non-profit support to the county efforts.

State departments, such as Transportation and Land and Natural Resources (DLNR) have separate authorities within their jurisdictions and HI-EMA provides the same support as with the counties noted above.

With respect to coastal infrastructure and sea rise hazards, HI-EMA participates in the DLNR’s Interagency Climate Adaptation Committee which coordinates state and county climate adaptation. In addition, the Federal Emergency Management Agency (FEMA) now requires the inclusion of sea level rise and climate change in our statewide all-hazards mitigation plan update which is due next year. FEMA approval of this plan update is required to qualify for Federal assistance during disasters. The report from the Climate Adaptation Committee, which is due at the end of this year, will have an important impact on this plan. A major deliverable of this mitigation plan is a list of mitigation projects that reduce the negative effects of a variety of hazards, including sea level rise and climate change. HI-EMA fully supports legislation, building codes, and setback rules that mitigate the future adverse effects of climate change and sea level rise. Being an island state, we are highly exposed to this hazard.

Department of Land and Natural Resources

The Department of Land and Natural Resources (DLNR) as a major coastal landowner, is concerned with possible impacts of the higher sea levels, such as:

  • Localized coastal erosion problems;
  • High-wave run-up and overwash, particularly with a south swell coinciding with high tides this weekend; and
  • Temporary ‘nuisance flooding’ in low-lying areas and storm drains.

Impacts anticipated this weekend are likely to be greatest on shorelines exposed to south swells that have experienced flooding or erosion in the past. Flooding impacts in June and July will be greatest if king tides coincide with a high wave event, storm, and/or rain. The high tides may back-up storm drains in low-lying coastal areas.

To help the community prepare and respond, DLNR joins with Sea Grant to recommend that landowners in low-lying shoreline areas or near waterways consider moving to higher ground any electronics, vehicles or other valuable from basements or yards.

Problems with localized flooding and increased currents around harbors could occur this weekend, particularly on south and west shores. The Division of Boating and Ocean Recreation encourages boaters to monitor their vessels to ensure mooring lines don’t get too tight, and to beware of overwash around boat ramps at high tide. Canoe clubs should secure or move canoes on the beach. Boating officials are not anticipating any impacts to state boating facilities as the tides are not expected overtop piers.

Marine biologist Skippy Hau, with the Maui Division of Aquatic Resources (DAR), says, “This weekend it’s too early in the season for turtle nesting to be impacted. The nesting season will begin in June and at that time biologists and volunteers will be monitoring the beaches for any signs of turtle nesting. Timing is critical — high tides could threaten nestlings as they emerge from the nest.”

Dr. Kim Peyton, estuaries and coastal habitat research scientist in DAR, notes that “King tides bring unusually high water levels, resulting in local flooding that can leave schools of juvenile fishes to die on roads, parking lots and other hard structures. When waves smash up against these hard structures, the deafening noise underwater can degrade habitat quality for juvenile fish in these altered estuaries.

She adds, “Under typical conditions, high tides hold back stream flow to the coast, then at low tides this wall of ocean water recedes and streams flood out into the ocean. King tides create a bigger wall of ocean water, meaning these tides can hold back streams to a greater degree and potentially cause streams to flood their banks even without rain in the mountains. Local current patterns in streams and bays may change temporally as the sharp shoulders of the King tides raise and lower water levels.”

Shoreline fishponds could possibly experience damage from high tides combined with unusual ocean swells.

DLNR is the state coordinating agency for the National Flood Insurance Program (NFIP) in Hawaii. It’s recommended that persons with properties in low-lying that may be affected by the King Tides take mitigative actions to protect their properties (i.e. use of sandbags to protect the structure or elevating personal property). If not already covered by flood insurance, talk to your insurance agent about protecting your home or business against flooding. Keep in mind, there is a 30 day wait period for a policy to take effect so don’t delay.

Department of Transportation

HDOT is in communication with UH SeaGrant on possible flooding during the King Tide events Memorial Day weekend, June 23-24 and July 21-22. We are coordinating with state and county emergency management and civil defense agencies on protective actions. Based on the tidal increases reported by DLNR, the HDOT Harbors Division, which has jurisdiction over the State’s commercial harbor facilities, does not anticipate major impacts.

On average, the commercial piers in Honolulu Harbor are constructed more than seven feet above sea level. Other pier facilities in state commercial harbors are constructed at even higher elevations above sea level.

HDOT Highways Division is planning on taking precautions similar to those taken for a heavy rain event. Crews will check storm drains and clear them as necessary and will be ready to respond after the tide subsides as needed.

HDOT Airports Division is, as applicable depending on the individual airport’s elevation, stocking sandbags and will check storm drains for ground water levels during the high tide.

In the long-term, HDOT is taking sea level rise into account as it begins to retrofit its existing harbor facilities. For example, in the design for the Kapalama Container Terminal (KCT) project’s newest pier, scheduled to begin construction this year. The design for the KCT pier takes into account sea level rise and anticipated water level heights over the pier structure’s useful life as means of being sea-level rise resilient. The KCT pier will be built at 9.81 feet, or over two feet higher than the current average height of piers within Honolulu Harbor. Also, where warranted, design parameters are being incorporated to address sea level rise and any anticipated environmental concerns at all commercial harbor facilities.

City and County of Honolulu

The Department of Emergency Management and the Department of Facility Maintenance Road Division will be monitoring the king tides and focusing on areas that have experienced flooding in the past. HPD will issue alerts if any road closures are necessary due to waves or flooding.

The severity of impact will be influenced by the size of surf that day. City emergency management officials are also working with marine forecasters now. Should the “King Tide” occur during high surf, the potential wave impacts will be increased.

This week’s efforts are just short term fixes. With climate change expected to cause sea levels to rise worldwide, planning and engineering solutions will be needed to properly address long term mitigation. The City and County of Honolulu recently opened an Office of Climate Change and Sustainability that is dedicated to planning these long term solutions.

Hawaii County

Hawaii County Civil Defense Agency attended a statewide emergency management video tele-conference meeting last week Friday to discuss the King Tide periods anticipated to intermittently occur over the next few months. We are monitoring information as it becomes available this week and will respond accordingly to any changes in forecasts associated with this hazard.

It is important to note that the 2017 hurricane season begins on June 1, 2017.  Close coordination with other county emergency managers, affected state departments, and the National Weather Service is high priority for Hawaii Island, and, consideration of the King Tides periods will be factored in to emergency risk assessments as well.

Maui County

Maui Emergency Management Agency (MEMA) is developing situational awareness with briefings and information from UH SeaGrant, NWS and HI-EMA. We are meeting to brief county partners tomorrow morning and will be using the Maka’ala mass notification system to push messaging out to the public.

Kauai County

The County of Kaua‘i is working with county, state, federal and non-governmental partners/stakeholders to ensure collective awareness, preparedness, and if need be, response readiness for potential impacts associated with the forecasted king tide events. The Kaua‘i Emergency Management Agency is taking the lead in partner/stakeholder engagement and coordination.

Based on input from our partners at the National Weather Service and UH Sea Grant Program, we are focusing our attention on areas, facilities and infrastructure that have been historically prone to coastal erosion, flooding and other hazards due to high surf and unusually high tide events. In addition, we are taking a close look at  tide-affected rivers and streams that could have issues if there are heavy rain or high-surf events.

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