Long-term Trends in Groundwater Levels in B.C.

Up to 1 million British Columbians are estimated to consume groundwater, and hundreds of groundwater aquifers provide water for industries, municipalities, farms, and rural homeowners in B.C. British Columbia operates a provincial observation well network of over 180 wells, which was established in 1961 to monitor groundwater availability in areas of high human use.

  • Observation wells are not used for domestic or commercial use, but instead provide information on groundwater levels over time.
  • Monitoring groundwater levels allows us to know how much groundwater is available given human use patterns, weather and climate patterns, and aquifer characteristics.1 Aquifers are geological formations of permeable rock, gravel, or sand containing or conducting groundwater.
  • This indicator presents a statistical analysis of long-term trends in groundwater levels recorded at 119 observation wells that have been monitored for ten years or more and were active as of 2004.
  • 78% of observation wells examined have water levels that are stable or increasing (with 4 wells showing increasing trends); 9% of observation wells show a large rate of decline in water levels (more than 10 cm per year), with a further 13% of wells showing a moderate rate of decline in water levels (between 3 and 10 cm per year).

Groundwater levels are sensitive to precipitation, aquifer storage capacity, recharge rate (the rate at which surface water trickles down to refill a groundwater aquifer), and human withdrawal. Groundwater level trends presented here indicate long-term changes in water level, but have not been corrected for changes in precipitation patterns or other factors. Thus, any significant trends are not necessarily directly attributable to human use. However, information on long-term trends can be useful for prompting further research and informing decision-making.

Methods

View the methods used to develop this indicator (PDF)

R package and code: We have developed an R package to facilitate working with, analysing, and visualising British Columbia groundwater level data. Download the 'bcgroundwater' package from GitHub. The source code for repeating the steps involved in processing the raw data (available from the Groundwater Observation Well data access tool) to make it suitable for analysis and repeating the analysis presented on this page is also available on GitHub.