Water in a Dry Season

The Island seems poised to experience one of the driest summers on record, so it might be good to re-visit that essential of Island life, its water supply.  Landowners play a large role in protecting and replenishing it.

As the cliché goes, ask most Islanders where their water comes from, and they’ll say the tap in their kitchen.  But more and more residents are getting interested in what’s known and what isn’t known about where their water comes from.

It’s always helpful to remember, in this regard, that for drinking water, the Island relies on what the U.S. Environmental Protection Agency has designated its sole-source aquifer—that is, an underground repository of water captured among sand, gravel, and, to a much lesser degree, clay and silt.  This aquifer is actually a series of inter-connected repositories amid at least two acknowledged aquifers, one relatively shallow and the other much deeper.  

The source of this water?  Streams, lakes, and pools caused by glaciation thousands of years ago and, most crucially for us, rainfall in the more recent past and the present.  Drilled wells tap into this collection of water deposits to deliver it ultimately to Island homes and businesses.

Add in the springs and surface water (for example, streams) that contribute to some Island water supplies, and that’s it.  No pipes from the mainland, no mysterious underground rivers of runoff from (depending on which strand of semi-mystical Island folklore you choose) Mount Rainier or the Olympics.  Just thousands-of-years-old water and the rainfall ever since.

People’s next inevitable question:  How much groundwater is there?  The simple answer is that no one really knows.  What’s clear is that water demand will likely increase with the drier summers that climate change is already delivering.  Development on the Island may increase water demand as well, though by how much is uncertain because of water-saving strictures applied to new buildings.

Most Islanders get their drinking water from seven of the large water purveyors on the Island.  Since these water utilities monitor their withdrawals, a rough idea of that demand is conceivable.  The problem is there are at least 124 smaller Group B systems (up to six hook-ups) that may or may not monitor water consumption and approximately 1,300 private wells whose owners likely don’t.

Wouldn’t it make sense to begin measuring water use from all these sources?  That’s the hope of the Island’s Groundwater Protection Committee, which has been working steadfastly for more than a decade to get a handle on this metric, and so much more related to the supply and health of drinking water on the Island.

One simple step to helping them is for all Group B system managers and private well owners to install a source meter on their system or well and then report usage volumes to that committee.