By Steve Ulvi
Special to the Journal
Remember the faded posters in grade school depicting the hydrologic cycle as it generally occurs on earth? Colorful illustrations with neat arrows showing evaporation from the equatorial seas and billowing storm clouds dumping rain and snow somewhat predictably depending on latitude, elevation and quirky weather gyres. To the young or uninformed, this massive energy transfer process seems magical, beyond human disruption, without limits.
But nearly every drop of water is hundreds of millions of years old, much of it probably from other planetary bodies toting ice, arcing in from interstellar darkness, or immense volcanic eruptions on a then lifeless earth. The salient point is that “they just don’t make water anymore”.
Even fools know water is everything. All life depends upon it. The most important substance for us just after breathable oxygen. But the variability in water abundance is all about geographic details.
Fresh water in our island archipelago is not as well understood, or perhaps as abundant as we imagine. Natural storage of winter rainfall varies from fractured bedrock aquifers, to deep glacial rubble to surface lakes and reservoirs. Maybe well over 90 percent of the unfathomable volume of precipitation on our islands ends up right back in the salt-chuck in farily short order.
In our panoramic view shed the high ranges capture rain and store snowfall to annually replenish aquifers, subsurface moisture banks and reservoirs connected by age-old dendritic patterns visible from space. But not so on these island bedrock landforms that shouldered 4,000 feet of grinding ice for tens of thousands of years prior to melt and the last incredible sea level rise that preceded the first human footprints on beach sand here.
The “genies” of physics and chemistry are well out of the bottle. Uncorked by human hubris and over a century of drunken sailor abandon in burning fossil fuels. The immense global circulation of air and waters based upon thermal gradients, earth spin etc., have fluctuated within broad regional “norms’ for the last 10,000 years of interglacial civilization growth.
Peopled landscapes the world over, always unequal in terms of dependable water, will be blasted or bypassed by the rivers of moisture carried in large scale atmospheric flows now shifting into a different gear.
The future climate regime here-like this year-is predicted to be one of longer, hot droughty summers and warmer, wetter winters pushing the freezing levels much higher. A pretty enviable forecast all in all. Given the seam-bursting pressures of regional population growth and severely diminished ecosystem services already out of whack, climate disruption will test every notion of social stability.
We are very fortunate to have citizen groups like Islands Climate Resilience stimulating a more specific public discussion about water resource volumes, conservation measures, policies regarding grey-water use, small scale desalination, agricultural uses, roof catchment, and ways to increase infiltration and limit surface runoff. Share your ideas at the townhall Water Forum on Nov.16 at the San Juan Grange.
To wait for government or big business to bring about the necessary changes in the way we value water, given our unique circumstances and the climate disruption on the horizon, is a fool’s gambit.
