The clear blue globe pictured atop North America represents the quantity of fresh water in the entire world.


by Jeff Dunster

It’s tough for people in Hawaii to imagine a water shortage, given that we reside in the tropics and are surrounded by water. However, if you were able to take the Earth’s entire water supply and fit it into a bucket, only one teaspoon would be drinkable.

That’s a sobering thought, and one that would not be lost on the nearly 770 million people on the planet who do not have access to safe drinking water.

On the surface, it seems like a third-world problem–but is it?

Water scarcity now affects every continent on the planet. A June 7 story in the Wall Street Journal read “Drinking Water Runs Low as Dry Conditions Drag On”. The dateline was Wichita, Kansas.

Other regions in this country are also impacted.  For example, the Colorado River is beginning to run dry. Lake Mead in Arizona—which currently supplies water to 22 million people, is also predicted to run dry in 8 years.

University of Hawaii Professor Tom Giambelluca recently testified at the Board of Land and Natural Resources stating, “Projecting future climate in Hawai‘i is difficult, and results so far remain uncertain in some respects.” One thing we do know is that rainfall over the Hawaiian Islands has been in decline since 1978. “As global warming persists, this trend is likely to continue through the end of this century”, says a joint University of Hawaii and University of Colorado study published in the March 13, 2013 issue of the Journal of Geophysical Research.

In a landmark scientific paper that appeared in Science magazine, leading water and climate scientists declared the death of “stationarity,” which has been the foundation of land and water planning on the Mainland (and Hawaii) for over a century. The loss of stationarity means one cannot assume that rainfall and the natural recharging of our aquifers will continue in the same way that they have for the past hundred years or more. In short, the precipitation that farmers have depended on in past centuries may not be there in the future.

“Short term fluctuations in rainfall don’t impact the water supply, or aquifer” said UH Oceanography Professor Emeritus Roger Lukas, who has studied climate change since the 1970s, “However, when longer term cycles such as an El Nino event and during the warm phase of the Pacific Decadal Oscillation (PDO), are in play is another story.” El Nino doesn’t directly affect the recharge, but affects the drawdown. PDO affects both draw down and recharge.

Should we be concerned about declining rainfall levels in the midst of growing demand?

Rainfall is Oahu’s primary water resource for streams and groundwater supply. This illustration depicts the hydrology of an island aquifer.

Like all things in this world, the value of water is determined by the laws of supply and demand. By the year 2035, the Department of Planning and Permitting predicts Oahu will need an additional 102,000 Housing Units. John White, Executive Director of Pacific Resource Partnership said in a May 23 issue of PBN that there are “about 340,000 homes on the ground today and that Oahu needs to add 33 percent more units to meet future demands.“

How much the population will grow is unknown at this point, but it’s certain the newcomers will need places to live, work, and recreate. The new infrastructure—the buildings, offices, parks, homes and schools will require an essential component that’s not mentioned in any of the slide shows or brochures for the new housing developments…water.

Will our island be able to sustain this new influx of population?

Barry Usagawa, the Program Administrator at the Water Resources Division at the Honolulu Water Supply, is confident there’s plenty of water to go around. He points to Koolaupoko Watershed Management Plan which the City of Honolulu’s projected increase of 270,000 people to the year 2030. “Although the increase in water demand did not materialize yet, there is available unused water supply on Oahu,” said Usagawa.

Despite ample resources today, in addition to increased demand, climate change can throw future reserves out the window as well. When weather patterns change, spurred by long term trends such as increased CO2 in the atmosphere and global warming, it’s anyone’s guess how that will impact rainfall.

For example, the Big Island has been suffering from drought for over 10 years brought on by Pacific Decadal Oscillation, a long-lived El Niño-like temperature pattern that has impacted parts of North America and Hawaii. As fluctuating weather patterns cause winter storms to migrate northward, away from Hawaii, the result will be less precipitation and more drought.

Barry Usagawa, of the BWS agrees that “We are unable to determine the trend, severity and occurrence of future climate change impacts”. He said he is “currently engaging the University of Hawaii in researching climate change so that our long-range water resource and capital plans can be adjusted”.

The Big Island is in the midst of a 10 year long drought brought on by Pacific Decadal Oscillation

“There are many strategies”, said Usagawa, “that we can pursue to protect our water supply and improve our outlook.” These include the protection of watershed, controlling invasive species, encouraging use of recycled brackish and non-potable water, desalination and a host of other measures.

UH Professor Lukas agrees that steps can be taken to conserve water resources but remains skeptical about long term prospects. “Ultimately we need to ask ourselves,” said Professor Lukas, “what is a sustainable population?” 

It is my personal belief, said the professor, “that at some point in the future, the supply of water on Oahu will not be sufficient at a reasonable price”.

I agree wholeheartedly with the good Professor.

There is enough water right now but I believe if we don’t take the proper measures, it will become so expensive people may think twice about turning on the tap.

Bottom two photos courtesy of the University of Hawaii

Jeff Dunster is the CEO and co-founder of Hawaiian legacy Hardwoods, a Honolulu-based company.