By Jenny Howell
A big part of my day to day job is to encourage the residents of Williams Lake and the surrounding region to conserve water. That gets a bit more difficult when lake levels are bursting, rivers overflowing their banks and every step you take oozes water out of the ground. Firefighters are questioning their purpose in life and Brianna from our own organization is pulling up her farm vegetables that are flooded under three feet of water.
So can you finally have those half hour showers again and stop nagging at your kids to turn off the taps? (though if my program is working, hopefully they are the ones reminding you).
Well, the answer is a definite no. If you’ve read any of my previous articles, you probably know that the City gets its water from an underground aquifer, deep below the Williams Lake valley. This aquifer was created by glacial scouring of a channel in the bedrock, which then filled in with sand and gravel to a thickness of about 60 metres. Then it was covered with many layers of till, silty sand and silt deposited by the lake on top (the ‘aquitard’), essentially covering the porous gravel/sand aquifer with a lid. This makes it a confined or semi- confined aquifer; the volume of water stored in the gravel is restricted by the bedrock and the cap of less permeable silt and till on top.
The aquifer gets recharged mostly from Williams Lake, slowly finding its way through the aquitard, but also from water draining through the ground along the walls of the valley and further up through the San Jose river watershed. When the City of Williams Lake first became concerned about the long term sustainability of the aquifer around fifteen years ago, the recharge rate was not quite meeting the demands of the city and there were concerns the aquifer was ‘drawing down’ and water levels were dropping. The issue with this is that as the gravel in the aquifer loses water, the silt/till lid on top can sink down and fill the porous gravel spaces (consolidation), so that the aquifer can no longer refill with water should it become available again. In other words, once an aquifer is lost, it is lost forever.
Since 2006, Williams Lake residents have responded amazingly to the Water Wise message. Water use is about 25 per cent lower than it was in 2006 and the recharge rate can now meet the current demands of the city. However, if everyone in Williams Lake looked at these last two wet summers and decided to forget everything they have learned about water conservation, a dramatic increase in water use could easily exceed the recharge rate again and put the long term health of the aquifer (and by extension, the town itself) at risk.
So, please keep having those short showers and turning off the taps as you watch the rain come down, knowing that you are an integral part of keeping this beautiful region and its resources protected for future generations.
Water Wise tip: Lawn pesticides and herbicides can be easily transmitted to local waterways. Choose environmentally friendly alternatives.
For more information on Water Wise or Waste Wise and any of our school and community programs, contact the Cariboo Chilcotin Conservation Society at firstname.lastname@example.org or visit the website at www.cconserv.org.