Gulf Islands contemplate a thirsty future as lakes, groundwater face ecological stress
By Stephen Hume,
Vancouver Sun
July 9, 2010

The tawny Gulf Islands, with their stunning views, near-Mediterranean climate of long, balmy summers and short, mild winters, have been a favoured destination since people first laid eyes on them.
What's not to love in the outcrops of arbutus and Garry oak: the drifts of chocolate lilies, the pocket coves for gunkholing sailors and gleaming shell beaches, not to mention the respite from rain and drizzle in a surrounding rainforest?

The challenge is not to love the place to death.

Overlooked in the recent contretemps over how zoning regulates development is the bigger question of carrying capacity.

How much more development can these islands really sustain? And it's not a question of how many people per hectare there are on this island or that, whether there are enough jobs on-island or not. It's a question of that basic necessity, water, and where it will come from.

Much of it now comes from wells. There's no clear picture of exactly how many because it isn't mandatory to submit withdrawal records and wells aren't regulated.

On Saltspring, about half the population is served by water from several small lakes. But those lakes already show signs of ecological stress, suffering algae blooms from too much phosphorus in the water and choking with water weeds.

The outlook is not rosy for groundwater, either. Aquifers are depleting as withdrawals exceed the recharge levels from winter rains and there's a problem with saltwater intrusion, a phenomenon that occurs when too much fresh water is extracted from an aquifer and sea water flows into the cavities. There are reports of wells drying up permanently, not just during the summers.

These arid islands with their fragile ecosystems were short of water when the first settlers arrived. Now many islands, including Saltspring, are already bumping up against their capacity to supply the water they need today, let alone what will be demanded by future development.

Over the past 30 years, the population of the Gulf Islands grew 142 per cent. The population of Saltspring Island, roughly 10,400 people, is now greater than what was then the population of the entire archipelago. From about 9,500 people, the Gulf Islands population grew to 23,000.

More people, more businesses, more summer cottagers all contribute to burdens on the carrying capacity of the region with respect to water.

One study shows that water demands on Saltspring, for example, are expected to jump by 36 to 47 per cent over the next couple of decades if development continues at the present pace. And summer water use increases by up to 200 per cent over winter demand when cottagers arrive.

Peter Lamb, coordinator of the Saltspring Island Water Council, says the organization's studies project that unless there are major gains in conservation, water will likely run out before the island achieves full build-out on available residential and business lots.

"We need to take a precautionary approach to development," he says. "We do have scope for reducing demand for water [through conservation], but there is a capacity issue."

The question of carrying capacity affects more than people. This arid oasis is home to a range of unique and endangered ecosystems populated by unusual and exotic creatures.

The Gulf Islands provide habitat for 15 of Canada's endangered species, 10 that are considered threatened and 13 more that are of special concern. They range from bats to butterflies and snakes to seabirds.

If climate change means even less rainfall over the region, as some models project, Gulf Islanders would do well to stop their ideological bickering over who regulates what and think hard about water, whether there will be enough and what they plan to do if it starts to run out.

shumeislandnet.com

© Copyright (c) The Vancouver Sun


Read more: http://www.vancouversun.com/technology/Gulf+Islands+contemplate+thirsty+future+lakes+groundwater+face+ecological+stress/3254768/story.html#ixzz0tIG54eY2