Mapping the likelihood of flowing artesian conditions in the Okanagan basin and Lower Fraser Valley, British Columbia

Drilling into an aquifer that exists under flowing artesian conditions can have significant environmental and socio-economic consequences. Unfortunately, the risk of drilling a flowing well in different regions of British Columbia is largely unknown. This study used Multi-Criteria Analysis and the Analytical Hierarchy Process to map the likelihood of flowing well occurrence in three hydrogeologic contexts based on aquifer type and location; 1) Okanagan Bedrock, 2) Okanagan Unconsolidated and 3) Fraser Valley Unconsolidated. A novel approach was used to determine the weights of each factor by using the Wilcoxon Rank Sum Test. Each map was determined to reasonably display and predict the extent of flowing artesian conditions by using the Wilcoxon Rank Sum Test to a significance level of 15%. Through site specific evaluations, Well Drilling Advisories are recommended to be developed by the Province for Naramata, Armstrong, and Aquifer 33 in Langley to alert drillers of flowing artesian conditions.