By Chris Moss

I have been thinking about the case for monitoring wells.  Domestic and commercial wells exist all over British Columbia. The BC government also operates observation wells all over BC although in Sooke and the Juan de Fuca Electoral Area there are only two wells, one shallow and one deep, on Philips Road.  The BC Ground Water and Aquifers site suggests that there are about 200 active domestic wells in the District of Sooke. These are mostly homes that are beyond the reach of the CRD piped water system.

In all wells there is a hydrostatic level of water where the upward pressure of the water table is equaled with the downward pressure of the atmosphere. This water level varies throughout the year, getting low in the summer and refreshing in the winter rains. Every time you turn on the tap you pull water from your well and the level goes down until you turn off the tap and allow it to refill to its normal hydrostatic level. 

Two events can alter the water level of your well.  The first is the drying trend of climate change. Less water falling as rain or snow on the watershed means less water seeping into the groundwater aquifers and into your well.  Long term records from the two Sooke based observation wells is showing that winter rains are no longer returning those wells to their previous levels, and that there is a slow downward trend over the years – less water to start the year and lower and lower levels of water in the late summer.  The second threat is development. Water in an aquifer is finite. Too many wells, or too much water being drawn out will lower the level of the water table and wells start to dry out.  A new house with a well within 300 meters of an existing well may also “drawdown” the level in your well, sometimes to the point that your pump is no longer able access water. 

Now this is where well monitoring will help you keep track of the fluctuating water level in the well.  A well tape is just a long marked tape with a sonic sounder on the end that you drop into your well. When the sounder hits water the reel at the top of the well beeps and you visually read the depth of the water.  We do this once a week and keep track of the level manually.  Newer devices use a sonar-like echo system to provide constant feedback to the user. These devices can be portable to use on several wells and include a data set that can be downloaded. Others are installed permanently to a single well  and can transmit data directly to your computer or phone. They can be programmed to take readings from every minute up to any standard time line you prefer.  They usually come with additional programming to allow you to produce graphs of your water use over time. You would be able see, for example if your new neighbour’s well is causing any drawdown on your well, or if you have an underground leak in your water line causing unusual drawdown.  You can follow the slow decent of your well water through the summer and know exactly how much water is above your pump for use.  These monitoring devices are not really expensive, about $1500 for a well tape and about $2500 for a sonar device.  When the average drilled well can cost you $30,000 to $70,000 dollars the cost of peace of mind for $2500 is a small add-on to the cost to know the health of your water supply at any time you choose.

In-place water monitors ought to be a required part of drilling a new well, and owners of existing wells should consider well monitoring as an added feature to the worth of their property.   

Chris Moss 606 Water Group