Hawaii First Water

Hawaii Community Foundation Releases Fresh Water “Blueprint for Action” for Hawai’i

Hawai‘i has been blessed with consistent rainfall, advantageous geology, and high-quality drinking water stores for centuries. Recent findings, however, have raised concern about long-term fresh water security for our Islands. University of Hawai‘i and other scientists have documented troubling trends including reduced rainfall, higher evaporation rates, and declining stream flows in recent decades. These findings, coupled with the demand of an ever-increasing population, suggest that Hawai‘i is entering an era of fresh water uncertainty.

The Hawai‘i Fresh Water Initiative (Initiative) was launched in 2013 to bring multiple, diverse parties together to develop a forward-thinking and consensus-based strategy to increase water security for the Hawaiian Islands. Organized by the independent, nonprofit Hawai‘i Community Foundation (HCF), the Initiative relied on a blue ribbon advisory panel of individuals (Hawai‘i Fresh Water Council or Council) with deep knowledge of water and a collaborative spirit to articulate a vision for a more secure and sustainable water future based on shared values, and shared sacrifice. This Blueprint is the result of their work, and provides Hawai‘i policy and decision-makers with a set of solutions that have broad, multi-sector support in the fresh water community that should be adopted over the next three years to put Hawai‘i on a path toward water security. The Blueprint also builds on the good work, findings, and recommendations over the years by preceding stewards of Hawai‘i’s most important resource.

To achieve the ambitious goal of 100 mgd in additional fresh water capacity, the group outlined three aggressive water strategy areas and individual targets that the public and private sectors must work together to achieve by 2030:

 

  • Conservation: Improve the efficiency of our population’s total daily fresh groundwater water use rate by 8% from the current 330 gallons per day/person to 305 gallons per day/person.1 By 2030, this goal will provide 40 mgd in increased water availability.

 

  • Recharge: Increase Hawai‘i’s ability to capture rainwater in key aquifer areas by improving storm water capture and nearly doubling the size of our actively protected watershed areas.2 By 2030, this goal will provide 30 mgd in increased water availability.

 

  • Reuse: More than double the amount of wastewater currently being reused in the Islands to 50 mgd.3 By 2030, this goal will provide an additional 30 mgd in increased water availability.

The Fresh Water Council distilled nearly two years of research and analysis into a single goal: creating 100 million gallons per day (mgd) in additional, reliable fresh water capacity for our islands by 2030.

 

Read the HFC’s  Blueprint for Action here…

 

Severe Drought Cripples Maui Ranch

July 2015, Lisa Kubota, MAUI (HawaiiNewsNow) –

The record-setting heat this summer is taking a toll on two Leeward regions already under severe drought. Kaupo Ranch on Maui is in one of those devastated areas.

A total combined head of 1,500 cattle grazed on the southern slopes of Haleakala five years ago. Due to the dry weather, that number has now fallen to 1,300 and will likely continue dropping.

The paniolo heritage at Kaupo Ranch traces back to 1929. When the rain falls, the remote property is blanketed with lush greenery. These days, however, much of the landscape is barren and brown.

“You just go into survival mode and do what you think you can do, prepare,” explained Kaupo Ranch manager Bobby Ferreira. “What I going get rid of? Lighten up as much as you can.”

See the rest of the article on HNN

Heavy rainfall events becoming more frequent on Big Island, Hawaii

5 Feb 2015, Science Digest and University of Hawaii/Manoa

 

A recent study by University of Hawai’i at Mānoa researchers determined that heavy rainfall events have become more frequent over the last 50 years on Hawai’i Island. For instance, a rare storm with daily precipitation of nearly 12 inches, occurring once every 20 years by 1960, has become a rather common storm event on the Big Island of Hawai’i — returning every 3-5 years by 2009.

In a paper published in the International Journal of Climatology, Ying Chen, a UH Mānoa graduate student at the time of the study, and Dr. Pao-Shin Chu, professor of atmospheric sciences at UH Mānoa and head of the Hawai’i State Climate Office, analyzed extreme precipitation events and the frequency with which they occur on three islands in Hawai’i — Oʻahu, Maui and Hawai’i Island.

While heavy rainfall events have become more frequent over the last 50 years on the easternmost island in Hawai’i, the opposite behavior is observed for Oʻahu and Maui to the west. There, rainfall extremes have become less frequent in the last five decades. This study, therefore, also reveals a regional — that is, east to west — difference in how precipitation patterns are responding to a changing climate.

“In the past, the frequency of heavy rainfall events was assumed to be fairly constant. However, because climate is changing, the assumption of stable precipitation climatology is questionable and needs to be reconsidered,” said Chu.

“Changes in the frequency of heavy rain events have repercussions on ecological systems, property, transportation, flood hazards, and engineering design — including sewage systems, reservoirs and buildings.”

This study also provides clues about why and how the frequency of precipitation extremes has changed. Chu and Chen found a greater number of extreme rain events during La Nina years and the opposite during El Nino years.

In this study, the number of rain gauges used was limited — the researchers used information from 24 weather stations on the three islands. For future work, Chu hopes analyzing data from additional stations will provide a more detailed assessment of changing rain patterns across the Hawaiian Islands.

Water as a System

Water as a System

Remarks by Kyle Datta, General Partner, Ulupono.  Presented at “Water Studies at UH: Next Generation Possibilities” – Kapiolani Community College, Oahu, Hawaii – November 13, 2014.

 

Aloha and Good Morning to Everyone.

Water is a system that unites and divides us.  The water system encompassed in the hydrological cycle integrates agriculture, energy, urban development, culture, watersheds, and the environment.  This understanding of managing water as a system goes to the very roots of Hawaiian culture.  The Hawaiian creation chant, “Aia I Hea Ka Wai a Kane”, translated means, “Where are the waters of Kane?”.  This chant is a series of riddles that reveal the hydrological cycle of these islands.

At Ulupono, our mission is to increase the amount of local food and energy while minimizing waste.  Since we take a systems perspective in our investments, we asked the question, “Do we have enough land and water to achieve our societal goals?”  We commissioned a three-year effort by the Energy Institute of University of Texas, Austin using East Maui as an example of the systems approach.  The findings are profound, not only here, but also nationally:

  • We have already reached the age of peak water. We must take the reality of peak water into account in our future water planning.
  • Climate change is and will continue to reduce the amount of water captured in all islands.  Overall, the state has 6 percent less rainfall already, and this will accelerate as the oceans warm and air currents change.
  • Climate change will accelerate species loss as rainfall shifts and temperature rise increases the range of invasive species.
  • Current course is unsustainable — Maui will run out of water.  Indeed, Oahu faces a similar fate, as both counties mine the groundwater aquifers at an unsustainable rate.

Hawaii River Restorations Reflect National Desire to Protect Water for Public Benefit

By Codi Kozacek
Circle of Blue

(28 October 2014)

Streams that have been drained dry for more than a century flowed again on the Hawaiian island of Maui last week following the return of water diverted to supply sugar plantations in the island’s arid central plains. The restorations are the result of a series of legal challenges to the commodification of Hawaii’s water—by state law a resource held for the benefit of the public—and are part of a national trend to protect tributaries and groundwater resources that support cultural, ecological and recreational water uses.

See Full Article Here

 

What is the Current State of Fresh Water Supplies in Honolulu and Oahu: Will We Have Enough Water for the Future?

By Larry Kobayashi,

Hawaii First Water, LLC,

12 September 2014,

20150306-DSC_2370

Executive Summary;

Within our grandkids’ lifetimes, Hawaii’s fresh water supply will likely not be able to handle the water demands of Hawaii’s increasing population due to decreasing aquifer levels and increased drought conditions due to long term climate changes.

  •  Oahu’s aquifers and streams have already begun to decline over the past decade. Expanding paved urban areas and decreasing agricultural production particularly on the island of Oahu–where a majority of the island’s population resides–will also further reduce fresh water resupply to the aquifers.

 

  •  Despite Hawaii’s growing population, the demand for fresh water to consumers has remained stable or reduced for reasons that are yet unknown to water officials.

Future scarcities can be forestalled by increasing conservation measures, more gray water reuse and eventually ocean water desalination which will come at an increased cost to future Hawaii economic growth and prosperity. Impending fresh water scarcities in Hawaii will favor those businesses and individuals who are taking a proactive approach to providing for their future fresh water needs.

 

 

1.  Where does Honolulu and Oahu gets most of its water?

Much of the population and economy of the islands is centered in Honolulu on the island of Oahu.  Most of Honolulu’s consumers get their fresh water from the island’s extensive aquifer systems.  Despite having the “wettest spot” of the world in the Hawaiian islands in Kauai, streams and other fresh water bodies are not reliable sources for fresh water in Hawaii.  The Honolulu Board of Water Supply uses four shafts, 12 tunnels and 84 well stations around the island of Oahu to tap water from the aquifers.  Water from these dike tunnels and wells is fed into nearly 2,000 miles of transmission pipes to household users.[1]

 

What are Fresh Water Aquifers?Aquifers are permeable rock formations from which fresh water can be drawn.   In some cases–in Hawaii–some of the wells are artesian which means water is naturally under pressure and flows to the surface without pumps.  This water is also sometimes called “fossil water” because it has taken hundreds or millions of years to filter down to the aquifer rock.  This water is not easily replaced if overdrawn.  Additionally in Hawaii, salt water intrusion caused by rising sea levels is also a potential concern for adequate future fresh water supplies.  In the early 90’s, most of the islands’ aquifers had their boundaries defined and their “sustainable yields”  (SY) were characterized to build baselines on their sustainability.

 

2.  What are the population trends for the islands?

The population of the State of Hawaii will continue to grow into the future placing greater demands on the state’s freshwater supplies.  The population of city and county of Honolulu will increase from about 876,000 (in 2000) to about 1,117,000 in 2030 increasing at about .8%, according to the State of Hawaii government.[2] These projections are on the conservative side anticipating that the number of military personnel will probably decrease due to budgetary pressures; however many of the military bases draw their water separately from the municipal systems although from the same aquifers.

 

3.  What are the rainfall trends for the Hawaiian islands?

The best long term climate models for rainfall predict that the Hawaiian islands will generally be get dryer over the next decades, according to a recently released study from the US Government.  For Hawaii, downscaled statistical models predict a 5%-10% reduction for the Hawaii wet season and a 5% increase in the dry season by the end of the century.[3]  The reduction in rain overall will increase the demand for fresh water from current rain fed irrigation systems placing increased strains on the aquifers.  Additionally people using rain fed household water systems such as those on the Big Island of Hawaii may seek alternative water systems such as wells and aquifers.

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4.  What do the records say about the amount of water in the aquifers feeding Honolulu?

Generally freshwater aquifers on Oahu are in a state of very gradual decline, according figures from the Honolulu Board of Water Supply and US Geological Survey.[4]  This is especially troubling since the Honolulu’s public demand for fresh water also leveled off during this time despite the addition of more consumers.  This suggests that the aquifers are incapable of maintaining this level of draw, a concern with the .8% annual population increase suggested for future Oahu.

Aquifer Chart Snip

 

An examination of US Geological Survey well data on Oahu also suggests fresh water well head declines in about half of the 15 sample USGS wells.  The accuracy of this examination is also significantly hampered by the large reduction of monitored wells due to budgetary constraints in the federal government.  Online records only suggest only two of the 21 wells are currently being monitored, although some records may be held locally according to the USGS.[5]

A similar picture of significant declines in water flow emerges when 20 of the main steams on Oahu are compared.  With the exception of the Manoa stream, all streams have declined by about half from 2004 to 2010.[6]  All together streams on Oahu carried 259 million gallons a day (mgd)  in 2004 and this was reduced to 121 mgd in 2010.  In addition to carrying storm water overflow after storms, the rivers function as a natural outlet for the island’s artesian springs and aquifers.

 

5.  What is the rate of water use in the City and County of Honolulu?

Municipal household water consumption has leveled off over the past decade on the island of Oahu since 2001 despite the nearly 10% increase in water users.[7]  Potable water use from 1990 through 2009 averaged about 155 mgd.[8] Since these figures do not include the large  agricultural users which have reduced over the past decades, most officials are at a loss to explain why per person water use has declined especially because water rates and costs have been stable for most of this period.  One possible answer for the decreased use of consumer water is the prevalent use of low flow showers and toilets.

 

6.  So will Oahu have enough water for its future needs?

The island of Oahu has sufficient fresh water to supply its near term needs but will begin to strain its fresh water supplies within 100 years.  The Hawaii State government estimates that the population on Oahu will increase to about 1,130,000 by 2030 which will demand approximately 206 mgd.  According to the Board of Water Supply, municipal users use about 76% of Oahu’s ground water compared to 24% for agriculture, military and other private users.

 

  • If this 24% of military and private users is added to the future 2030 predictions of 206 mgd for municipal users, the total would be 274 mgd for the island of Oahu. Not including brackish water supplies, the Board of Water Supply estimates that it should be able to sustain 407 mgd from its fresh water aquifers, according to its best data.

 

  • Using the State of Hawaii’s own population “high growth” scenario for Oahu, the island could begin to reach this 407 mgd maximum within a century.[9]

 

The estimate of 100 years is probably on the high side.  There is a large degree of uncertainty about the real sustainability of Oahu’s aquifers.

 

  • Especially since the aquifers have been gradually declining even though consumers are using fresh water at well below max sustainable rates indicating they are not replenishing even at with this moderate rate of use.

 

  • This may be due to the gradual urbanization of the island which is increasing the area of non porous surfaces; such as roads and cityscape and this trend will only increase in the future. The increase of non porous surfaces causes rain to more rapidly run into the oceans instead of seeping into the ground.

Finally the impact of climate changes will almost certainly bring worsening conditions to the aquifers in the form of less rain and higher sea levels which will gradually increase the salinity levels of the aquifers making more of the water unusable without treatment.[10]

 

7.  What if the estimates prove wrong and the aquifers begin to run dry earlier, what can be done to meet the future fresh water needs of Oahu?

Because of the location of the Hawaiian islands in the middle of Pacific Ocean, the islands do not have the backup reserve of water supplies that say Los Angeles or other mainland areas have.  Additionally the supply of water has been deemed a consumer “life” service which no household consumer can be deprived of due to their inability to pay which means that a delicate balance of use and conservation must be maintained.

Conservation measures is the best way to begin to control the use of fresh water by island consumers.  One of primary means is by conducting household water use surveys and ensuring that all households have meters to understand their water use baselines.

 

  • According to a California water saving survey report, metering will generally save about 20-30% overall and residential awareness surveys will generally achieve 32.2 gallons per day (gpd) of savings.[11]

 

  • Low flow toilets will generally save 21.2-27.2 gpd per single family household.

 

  • High efficiency washing machines will save about 85-109 gallons per week per household.

 

  • Low flow shower heads (5.5 gpd), toilet dams (4.2 gpd) and aerators (1.5 gpd) making up the difference.

Water reuse and the use of brackish (somewhat saline) water is another means to increase the “effectiveness” of water.  Hawaii has begun to reuse some of its water on golf courses and for power plant cooling.  Increasing the use of “gray water” from showers and washers will require some minor though not insignificant modifications of households to reuse the water to flush toilets and water gardens.  Some municipalities have begun to filter their gray and even toilet sewer water for reuse, but such uses involve extensive public education programs to overcome the “ick” factor.

Because of Hawaii’s extensive rainfall in some parts of the islands, increased use of stormwater mitigation strategies can effectively control “brown water” run off and potentially become a source of increased fresh water on the islands.  Stormwater run off can be funneled into rain barrels for household use and may be used to help reinvigorate aquifers in some limited circumstances.  Finally, Hawaii might have to increase the historical use of cross island pipes and troughs to move water from the eastern wet sides to the western drier areas of the islands to help with distribution of water when it is present.

Desalination is increasingly becoming more technically and economically viable.  Some municipalities in southern California are using economically viable “reverse osmosis” filtration methods to create fresh drinking water.  Because of its very arid conditions and the wealth of the its government coffers, Middle  Eastern countries such as Saudi Arabia have been using desalination technologies for drinking water for a number of years.  On some Hawaii islands wind energy creates power when demand is low, Hawaii could begin to use this surplus energy to desalinate sea water in the future when supplies are scarce.

[1] Honolulu Board of Water Supply one pager on “How Does Water Get To Your Tap?” from BWS website.

[2] Honolulu Board of Water, “Ko’olau Poko Watershed Management Plan,”  19 December 2011.

[3] National Climate Assessment 2014, Chapter 23, Hawaii and US Affiliated Pacific Islands, 2014, page 542.

[4] Minutes for the Honolulu Board of Water Supply from 2005 to 2014.

[5] USGS National Water Information System, USGS Water Resources Database, as of 7/2014.

[6] Honolulu Board of Water Supply, “Ko’olau Poko Watershed Management Plan,” 12/19/2011, pg 1-35.

[7] Honolulu Advertiser, Oahu Drinking Water Use Down 7% since 2001, 9 Aug 2009.

[8] Honolulu Board of Water Supply, 12/19/2011, 1-20

[9] State of Hawaii estimates total aquifer capacity at 407 mgd minus 68 mgd (ag/mil use) minus 212 mgd (2030 est) =127  which is divided by SOH estimate of 1.6 mgd increased use per year gives 80 years from 2030 or 2110 till demand equals projected sustainable yield

[10] National Climate Assessment 2014, Chapter 23, Hawaii and US Affiliated Pacific Islands, 2014, page 542.

[11] A and N Technical Services, Analysis of Urban Water Conservation Best Management Practices prepared for The California Urban Water Conservation Council, March 2005.

Scientists Project Rainfall Frequency and Intensity Over Next 30 Years

University of Hawaii; 2011 – Manoa have projected an increased frequency of heavy rainfall events but a decrease in rainfall intensity during the next 30 years (2011-2040) for the southern shoreline of Oahu, according to a recent study published in the Journal of Geophysical Research.

178122558Chase Norton, a Meteorology Research Assistant at the School of Ocean and Earth Science and Technology (SOEST) at UH — Manoa, and colleagues (Professors Pao-Shin Chu and Thomas Schroeder) used a statistical model; rainfall data from rainfall gauges on Oahu, Hawaii; and a suite of General Circulation Models (GCMs) from the Intergovernmental Panel on Climate Change (IPCC) to project future patterns of heavy rainfall events on Oahu. GCMs play a pivotal role in the understanding of climate change and associated local changes in weather.

Heavy rainfall and flash floods are common in the Hawaiian Islands due to their steep terrain, rain‐producing weather systems, and abundant moisture supply. They have caused multimillion dollars damage to homes, properties, roads, agriculture, and other sectors. Environmentally, heavy rainfall and runoff events in Hawaii, which are likely to cause slope and coastal erosion, pollutant discharges to the near shore marine environment, coral reef degradation, among others, are expected to change as Earth undergoes an unprecedented warming. Given the socioeconomic repercussions resulting from past storm events, it is of considerable interest to investigate changes in the frequency and intensity of heavy rainfall events in Hawaii, particularly for Oahu, as it is the most populous island in Hawaii.

“The results presented in this study may benefit many agencies who are concerned with floods and relevant policy-making in the face of climate change,” says Chu, UH – Manoa Meteorology Professor, Hawaii State Climate Office Director, and co-author of the study. “For instance, changes in rainstorm intensity may be a serious consideration in aquifer management – as precipitation is the primary water source for streams and groundwater supply.”

Norton, Chu, and Schroeder would like to use the IPCC GCM simulations and extend the rainfall model to project future events in other locations. They also plan to use a high resolution regional climate model to project future changes in water resources in the Hawaiian Islands.

Story Source:

The above story is based on materials provided by University of Hawaii ‑ SOEST. Note: Materials may be edited for content and length.

Journal Reference:

  1. Chase W. Norton, Pao-Shin Chu, Thomas A. Schroeder. Projecting changes in future heavy rainfall events for Oahu, Hawaii: A statistical downscaling approach. Journal of Geophysical Research, 2011; 116 (D17) DOI: 10.1029/2011JD015641

Documented Decrease in Frequency of Hawaii’s Northeast Trade Winds

Source: University of Hawaii ‑ SOEST, Date: October 2012:

Summary: Scientists have observed a decrease in the frequency of northeast trade winds and an increase in eastern trade winds over the past nearly four decades, according to a recent study.

Clouds and rain over Oahu Hawaii

Clouds and rain, as seen here over the island of Oahu, Hawaii, are influenced by trade wind patterns. Credit: Chris Ostrander – University of Hawaii at Manoa, SOEST

Scientists at University of Hawaii at Manoa (UHM) have observed a decrease in the frequency of northeast trade winds and an increase in eastern trade winds over the past nearly four decades, according to a recent study published in the Journal of Geophysical Research. For example, northeast trade wind days, which occurred 291 days per year 37 years ago at the Honolulu International Airport, now only occur 210 days per year.

Jessica Garza, a Meteorology Graduate Assistant at the School of Ocean and Earth Science and Technology (SOEST) at UHM; Pao-Shin Chu, Meteorology Professor and Head of the Hawaii State Climate Office; Chase Norton; and Thomas Schroeder analyzed 37 years of wind speed and direction, and sea level pressure data from land-based weather stations, buoys and reanalysis data.

Persistent northeast trade winds are important to the Hawaiian Islands because they affect wave height, cloud formation, and precipitation over specific areas of the region. When trades fail to develop the air can become dormant and unpleasant weather can develop.

Furthermore, Chu explained that the trades are the primary source of moisture for rain, and that a dramatic reduction could fundamentally change Hawai’i’s overall climate.  “We have seen more frequent drought in the Hawaiian Islands over the last 30 years,” he noted. “Precipitation associated with the moisture-laden northeasterly trades along the windward slopes of the islands contributes much of the overall rainfall in Hawaii.”

According to the National Drought Mitigation Center’s State Drought Monitor, nearly 50% of land in Hawaii has experienced some degree of drought during the past year.  While previous research has focused primarily on changes in trade wind intensities, this work, along with Chu’s 2010 study, is among the first to show changes in trade wind frequencies.

“In 2010, we only studied the trade wind changes at four major airports in Hawaii (Honolulu, Kahului, Hilo, and Lihue). In the current paper, we expanded our study to include four ocean buoys in the vicinity of Hawaii and a large portion of the North Pacific,” Chu commented.  In the future, these scientists will be using model simulated data to further understand the dynamics of rainfall and trade winds, and estimate future patterns.

Story Source:

The above story is based on materials provided by University of Hawaii ‑ SOEST. Note: Materials may be edited for content and length.

Journal Reference:

  1. Jessica A. Garza, Pao-Shin Chu, Chase W. Norton, Thomas A. Schroeder. Changes of the prevailing trade winds over the islands of Hawaii and the North Pacific. Journal of Geophysical Research, 2012; 117 (D11) DOI: 10.1029/2011JD016888