Climate Change & Sea Level Rise – Waimanalo Rainbow Village

11-14-2021 Updated post by alohahawaiionipaa org. – Please contact us for any questions.

Waimanalo Rainbow Village –A Truly Affordable Housing Proposal

(A “Canary-in-the-Coal Mine” for acknowledging Climate Change1 and Sea Level Rise?)


The proposed Waimanalo Rainbow Village (WRV) project shown on the left that envisioned truly affordable housing for up to 3,000 of Oahu’s almost forgotten residents seemed to be dead on arrival because of the City Council representative`s support of the Neighborhood Board’s position such as Not in our neighborhood.2 It nevertheless gained broader public support because of the dire need for truly affordable housing that has come again into focus because of the Pandemic and the “out-of-the-world” accelerating Real Estate prices.3

Mitigating the flooding of the expected sea level rise of about three feet (1 m.) or more due to Global Warming by keeping the building footprint at the highway elevation while stepping down to the individual garden plots, the location was ideal for not only providing truly affordable housing with small scale farming and ready beach access often not feasible for the less fortunate, but also promised to make a great impact on reducing homelessness. The buildings (except for the proposed solar panels) were designed to withstand even deadly typhoons such as were witnessed in Japan and the Philippines, and to serve as “shelter-in-place” should unforeseen emergencies suddenly arise. Since there are no hardscapes ocean-side of the structures, sea level rise and with it expected erosion would not eliminate the sandy beaches but just move them further inland.

However, the hoped-for reduction in Global Warming during the Covid Pandemic did not materialize, as stated in alarming new 2021 scientific reports that document the runaway Climate Change/Global Warming Crisis and with it the seemingly unstoppable sea level rise. We have therefore been informed by “more reliable sources” that the project as envisioned in its location will not be feasible because of the seemingly unstoppable sea level rise that apparently will exceed the State’s present 3 feet rise benchmark (project site shown in orange on the photos at the end of this report).  This would also include adjacent areas such as the Bellows Air Force Base where Waimanalo Neighborhood Community members had expressed their desire to establish a true Native Hawaiian Village if the lease agreement with the military (expected to expire in 2029) is not renewed. However, we have now been informed that Bellows is unique in that the U.S. Government has legal title to it but that it may consider returning the former bombing range (TM001) adjacent to Waimanalo Bay Beach Park after restoration is completed which could then be used for recreation and cultural practices. The proposed project location is therefore being re-evaluated in relation to other presently ongoing construction on the island where sea level rise and inundation is more imminent. Safety and long-term affordability are our concerns. It is high noon that government agencies provide alternate sites for safe and truly affordable housing and not just on a piecemeal basis.

The Hawaii State Office of Planning & Sustainability already acknowledged in its 2017 report that beaches will largely disappear from Oahu because of sea level rise. Even just a 3-foot sea level rise, while heavily impacting Waikiki, the State’s breadbasket due to tourism, would also inundate Kaka’ako’s Ala Moana Blvd. where construction approved for the more affluent has continued at an almost breathtaking pace, irrespective of the dire consequences of predicted inundation in the not-too-distant future.

Specifically, what was known, what was updated, and what meaningful actions have been taken to protect Oahu and Hawaii from sea level rise if possible? Perhaps little besides talk. The “Pacific Islands Ocean Observing System (PacIOOS) 2014 Honolulu Sea Level Rise-Inundation Risk” map shown above clearly indicates the expected disasters awaiting Hawaii.

Even “only” a now-unstoppable three-foot sea level rise would inundate the areas around the Ala Wai Canal in Waikiki while high tides are already eating up Waikiki’s beaches. Without the canal, Waikiki would not exist as it collects the mountain’s flood waters while unfortunately also letting the ocean extend inland, flooding the surrounding areas as the water level rises and falls with the ocean’s tides. Before this happens, rising ground water which cannot be controlled would cause localized flooding perhaps already within the next decade.

In coastal Kaka`ako, which like Waikiki was once a marshland with groundwater and sea water incursion as well as sink holes being common soil problems, a reduced version of the Ala Wai Canal has created a similar situation with a smaller flood canal running ocean side, parallel to Ala Moana Blvd. Without it, Ala Moana Beach Park, the most heavily visited park in the State, would not exist as the canal collects flood water and channels it into the ocean while at high tide again filling up part of the canal. An apparently behind-schedule one-year Capital Improvement Project at the estimated cost of $4.62 mil. was started in December 2020 to repair the collapsed and damaged drainage canal walls and replace two pedestrian bridges and widen them from ten to twenty feet to align with existing crosswalks for easier pedestrian access to the park. Unfortunately, none of the work being carried out can or is expected to mitigate the initial expected flooding and then inundation of Ala Moana Blvd. as sea level rises to an unstoppable 3 feet perhaps already a little past the middle of this century. The present highest average high tide of 2.2 feet would see the water mark rise to 25” below the lowest point of the reconstructed walls westerly along Ala Moana Blvd. while a 2.7-foot King tide would raise it to about 19.” However, flooding along Ala Moana Blvd. will occur much before that.

Sea water intrusion is already occurring in many areas on Oahu and is compromising the State’s coastal infrastructures. For example, Hawaii News reported on March 15, 2018, that City storm drain inspectors were somewhat shocked when a city storm drain inspection near Pensacola Street found deteriorated culvert concrete top slabs and six feet of salt water and sediment in the 8-by-8-foot boxes, whose top slabs showed significant spalling, meaning that the concrete was flaking away from the reinforcing bars. Salt water intrusion in the boxes was found as far inland as Beretania Street.

2017 12-10-Storm drain culvert repair across Ala Moana Blvd.

HDOT, the Hawaii Department of Transportation, quickly announced a temporary vehicle weight restriction of no more than 25 tons with a speed limit of 25 mph on Ala Moana Boulevard between Piikoi and Queen Streets in both directions, while temporary shoring was carried out in April for the Ala Moana Blvd. Pensacola storm drain section. This included cleaning over 700 linear feet of culvert along with the use of divers. New designs being complete, two parallel box culverts constructed in 1971 were replaced across Ala Moana Blvd. by the end of the year, with the cooperation of the affected neighborhood association which waived the noise restrictions so that extended night work could be carried to complete the project quickly during the rainy season along with savings to the state. $50 million in the CIP (Capital Improvements Program) was then further budgeted to continue such work uphill to Kapiolani Blvd. and beyond, with work scheduled to start as early as 2020 or 2021.

The groundwater/sea water infiltration/inundation found by City inspectors in Kaka`ako as far inland as Beretania Street is not surprising according to a Hawaii News report dated May 3, 2020. It quoted a recent study by researchers at the University of Hawaii in Manoa with coastal geologist Shellie Habel as lead author. The study found that more than a quarter of initial flooding is attributed to groundwater inundation alone, while groundwater inundation, water backflow from drainage systems, and direct flooding from the ocean will eventually account for more than half of the projected flooding generated by climate change. Storm surges, hurricanes and typhoons, as well as intensive rainstorms, can of course also quickly accelerate coastal inundation.

“The top threat, groundwater inundation, occurs as a rising ocean lifts Oahu’s caprock aquifer, an underground lens of brackish and polluted water that floats on a base of higher-density saltwater connected to the ocean. During high-tide events, the groundwater breaks the surface to create temporary urban wetlands that grow even larger when high tides and rainfall coincide. Over time, in perhaps as soon as three decades from now, those wetlands will become permanent. And, increasingly, the standing water will require special engineering, costly public works and other measures to help the city continue to function and thrive.”

It was also emphasized that sea walls cannot mitigate groundwater inundation!

While placing the focus on the effects of sea level rise, existing storm drain systems are already overwhelmed during runoff from high intensity storms or even backflow of sea water into the system as things stand now. A look at the clearly visible Ala Moana Blvd. canal storm drain outlets brings this into focus. The largest, most critical storm drain outlet into the canal is located across from the 30-year-old Nauru Tower high rise westerly of Piikoi Street. When the culvert bridge across Ala Moana Blvd. was rebuilt in the fall of 2017, the outlet remained at the same elevation. Presently its outlet is already reduced to about 1 foot in height/clearance at a 2-foot high tide, and will not properly function, as ground water rises along with sea level, with backwash from nearby “manholes” then starting to flood the area such as can be expected when King Tides (such as the 2.66-ft. high tides of Dec. 4-6, 2021) occur during high intensity storms. These high tides would also compromise emergency backflow/outflow (if possible) to the ocean via the Kawala Basin Harbor (then blocked by the Ala Moana Park Drive culverts) if lagoons become inundated such as at the easterly Kahanamoku outflow.

Storm drain culvert outlet at Ala Moana Blvd. across from Nauru Tower at 2 ft. high tide.
Culverts under Ala Moana Park Dr. at 2 ft. high tide.
Bridge under Kawala Basin Park at 2 ft. high tide.
Channel wall repair along Ala Moana Blvd. across from Ward Village.

Similar flooding scenarios could also affect the 60-acre Howard Hughes Ward Village project being extended with more and more high rises for the more affluent (despite the fact that Kaka`ako’s masterplan envisioned it as a mixed income community), as well as perhaps even Kapiolani Blvd. where construction is also continuing as if there were no tomorrow.

Did the City and County of Honolulu Climate Change Commission not issue a report in 2018 on Climate Change and sea level rise based on 2017 scientific data? Yes, since the Commission had been charged with gathering the latest science and information on climate change impacts to Hawai‘i and providing advice and recommendations to the mayor, City Council, and executive departments for the drafting of policies and planning for future climate scenarios and reducing Honolulu’s contribution to global greenhouse gas emissions. Its then summary of key findings were:

  1. The projected median global temperature increase this century is 5.8°F (3.2°C).
    a. The likely range of global temperature increase is 3.6 to 8.8°F (2.0 to 4.9°C), with a 5% chance that it will be less than 3.6°F (2°C) and a 1% chance that it will be less than 2.7°F (1.5°C) by the end of this century.
  2. Relative to the year 2000, the projected rise of global mean sea level (GMSL) by the end of this century is 1.0 to 4.3 ft (0.3 to 1.3 m).
    a. Relative to the year 2000, GMSL is very likely (90 to 100% confident) to rise 0.3 to 0.6 ft. (0.09 to 0.18 m.) by 2030, 0.5 to 1.2 ft. (0.15 to 0.36 m.) by 2050, and 1.0 to 4.3 ft. (0.3 to 1.3 m.) by 2100).

The above was the then best case scenario. But the report also stated the then worst-case scenario of a planning benchmark of 6 ft. (1.8 m.) sea level rise by the end of the century with chronic high tide flooding even decades earlier based on the fact that global emissions are on a warming pathway of over 5.4℉ (3.0℃). Could a 3.2 ft. (1 m.) sea level rise then not already be reached even before 2060?4

If so, what about the 20-mile-long elevated rail project that was barely approved by the voters with a cost of $5.12 billion and a promised completion date of 2021? With the public having no control over it anymore and as managed by the Honolulu City Council, its cost has now mushroomed to over $11 billion and rising, with a new estimated completion date of 2031.

Will its final 4.2 mile yet unfunded extension into Kaka`ako and ending at Ala Moana Shopping Center not put these last four rail stations under water as shown in black along the yellow rail line? The Hawaii Thousand Friends, a 501 (c) (3) nonprofit, answered this question with a resounding yes, stating that they will be under water during high tide within the next few decades, yet the only change to the rail project has been to raise stairway landings by six feet, leaving commuters to negotiate flooded streets on their own. They then proposed to reroute the rail along Beretania Street to the University of Hawaii main campus in Manoa instead of flood-prone Kaka`ako. If this section is to be completed at all would then depend on initial ridership evaluation.

The Hawaii Thousand Friends also pointed out that the current rail route was planned in the 1990s before there was worldwide consensus on global warming and its effects on sea level rise, and that there is now widespread agreement that sea levels in Hawaii will rise between 3.2 and 6 feet (or more?) by 2100. It was also emphasized that more recent studies indicate that sea level rise, flooding from groundwater inundation, and reverse flow through the municipal drainage system could result in dangerous and impassible roadways in Honolulu already by the 2030s. Their report concluded with the statement that State and County officials have stressed the need to plan for the impact on low-lying areas, but that only token changes have been made to the rail project (and elsewhere).

As already stated earlier, the hoped-for reduction in Global Warming during the Covid Pandemic was not realized. Alarming new 2021 scientific reports now document the run-away Climate Change/Global Warming Crisis that makes a six-foot sea level rise even before the end of this century now an almost certainty.

The National Oceanic and Atmospheric Administration’s (NOAA) sea level rise viewer that shows expected sea level rise and coastal flooding impacts above average high tide, now graphically indicates what will happen with a 3, 4, 6 and 10-foot sea level rise as indicated on pages 6-10. With just a four-foot sea level rise, more than half of Waikiki would be under water as well as Kaka`ako. At a six-foot sea level rise, Kaka`ako, Waikiki and the shoreline extending easterly would largely cease to exist. This mirrors this country’s past and present unwillingness to sacrifice a little and be a leader in supporting alternative energy instead of being one of the world’s leading fossil fuel polluters along with China. A six-foot sea level rise, while perhaps not impacting the structures of the Waimanalo Rainbow Village directly, could greatly compromise its farming and “backyard” food production because of potential storm surges and seawater infiltration.

This photo, shown on one of the Howard Hughes Web sites, illustrates in white the ongoing, high rise condo construction at their 60-acre Kaka`ako Ward Village complex and states “The community sits on prime oceanfront Hawaii real estateHistorically a non-residential warehouse district, Kakaako is going through an incredible revitalization and Howard Hughes is leading the way with potentially up to 20 new towers within the next decade.”

However, this coastal site is expected to be already largely under water with just a three-foot sea level rise. Apparently there is almost total Climate Change denial by developers and government agencies when it comes to being proactive. If not, what proactive work is being carried out already to compensate for/mitigate the expected sea level rise? If approved, who will actually foot the bills when the flooding impacts are felt, which could already happen before these 20 high rise towers are fully occupied? When will homeowner assessments or fee increases be required for expected additional maintenance related to mitigating Climate Change impacts if and where feasible? When will storm water fees be assessed or bonds floated for maintaining or rebuilding infrastructures?

All public agencies in the State of Hawaii must immediately work together and acknowledge that, in addition to higher temperatures in a humid environment, a sea level rise of six feet may become unstoppable, and that its devastating effects will not be felt by the end of the century but already within the not too distant future, as it is already being felt in more vulnerable countries around the world. County, State and Federal agencies must therefore also identify land for truly affordable rental housing and relocation of the most vulnerable population, and follow through with passing legislation to purchase such land while providing funds for construction and infrastructure enhancement.
Past efforts by government agencies to pass the buck to private industry to create truly affordable homes for purchase and rental have failed, while the Real Estate prices have gone through the roof, largely fueled by out-of-State investors. Along with a unified approach to mitigate the now inevitable massive impact of Climate Change, Government agencies must acknowledge that there are no truly affordable homes for purchase or especially rental housing for the working class in Hawaii anymore. The absence of a livable wage, the subsequent breakup of society’s fabric—the family—and mental health issues that arise with it, are creating an almost unstoppable avalanche of homelessness that will haunt Hawaii from here on out unless immediate action is taken in providing truly affordable housing.
We can’t pass the buck and state that there is no money to move ahead. If just $2 billion would have been earmarked on providing truly affordable housing for the working class and for mitigating Climate Change instead of continuing to spend the money on elevated rail, largely now viewed as a politically motivated “pork-barrel” project, Hawaii could now be more in control of its own destiny.

While it may not be feasible to build the WRV in the location as proposed because of possible sea level intrusion starting already with less than six feet sea level rise (and alternative sites must be found by government agencies), it is strongly recommended that no further new construction be permitted on Oahu in at least the NOAA expected 4 feet sea level rise zone. Food production self-sufficiency must also be made a top priority along with every drop of rainwater and runoff collected where feasible to enhance small scale farming and “backyard” food production.

1 Climate Change is largely the result of burning fossil fuels, which puts greenhouse gases in the atmosphere and warms the planet. The climate disasters that are now occurring are the result of the global average temperature warming by only 1 degree Celsius above pre-industrial levels. Two more degrees of warming — for a total of 3 degrees — would result in ever more powerful hurricanes, unstoppable wildfires, droughts and heat waves, a drastic drop in food production, famine, hundreds of millions of climate refugees, and the spread of illnesses and diseases. Even if countries meet the commitments they made under the 2015 Paris Agreement, the world is heading toward a warming of more than 3 degrees. The drastic transition away from fossil fuels toward renewable energy that everyone has been talking about for decades has not happened.

2 We understand, as told to us by long-term public servants, that the lack of affordable and truly affordable housing is because (1) homeowner associations are opposing it, with (2) elected officials not having the courage to step up to the plate and support it, and if there was support, (3) threats of or lawsuits filed by the opposition. If, for example, any of the nine elected members of the City and County of Honolulu Council is pressured by a Neighborhood Association or Community activists to oppose an affordable housing project in its district, the other Council members will acquiesce even if that member was for such a project and changed his/her mind in the last minute.

3 A case in point of the mushrooming homelessness avalanche developing is the following: A hardworking jack-of-all-trades journeyman had upgraded an over thirty-year-old, empty four-bedroom house largely at cost with the owner’s promise that he could purchase it at about $800,000 (below the proposed appraisal of $950,000). Friends that pledged to financially support him in his purchase urged him to immediately sit down with the owner and start the purchase transaction. At this point the owner stated that he had just placed it in the hands of Real Estate agents. The bidding war apparently started immediately, with the appraisal increasing substantially and the property subsequently selling for over $1.5 mil. with the influx of out-of-state money. Since the journeyman’s rent on the home he was leasing also increased accordingly, he is forced to downgrade and find a smaller rental home for his family, whose grown-up teenage children will be “out-on-the-streets” unless he continues to also provide a roof for them.

4 The 2018 report also states:
*With just 3.2 ft. (~1 m.) of sea level rise, almost 18 mi. (30 km.) of Oahu’s coastal roads will become impassible, jeopardizing access to and from many communities.
*Oahu has already lost more than 5 mi. (8 km.) of beaches to coastal erosion fronting seawalls and other shoreline armoring. Many more miles of beach will be lost with sea level rise (if widespread armoring is not done).
*State and County agencies should consider potential long-term cost savings from implementing sea level rise adaption measures as early as possible (e.g., relocating infrastructure sooner).
*3.2 ft. (~1 m.) sea level rise will result in $12.9 bill. structure and land loss, 3,800 structures flooded, 13,600 residents displaced, 17.7 mi. of major road flooded.


(NOAA) Expected sea level rise and coastal flooding impacts above average high tide
(Click to enlarge)