| Abstract/Description or Keywords |
Groundwater on Salt Spring Island, British Columbia, flows through fractures in sedimentary and igneous rock aquifers. Recharge is dominantly by rainfall infiltration. Some wells near the coast are known to be impacted by saltwater intrusion. Despite the differences in scale for testing, and rock type, pumping and tidal response tests yield similar averages across the Gulf Islands. Transmissivity is estimated on the order of 10-5 to 10-4 m2/s and hydraulic conductivity on the order of 10-7 to 10-6 m/s. Using Visual MODFLOW, a steady-state fresh groundwater simulation for the Swan Point area generated a representative flow system and established a reasonable range for the aquifer properties. A tidally-forced transient model simulated the tidal response and further constrained the aquifer properties. Next, a density-dependent flow and transport model was constructed in SEAWAT to simulate the current position of the saltwater interface, which was found to be near vertical at the coast. |
