WSA Saskatoon
Observation well WSA Saskatoon was constructed in 1967 to a depth of 27.05 metres to monitor natural groundwater level fluctuations in the intertill Forestry Farm aquifer. This aquifer is formed by fine to medium grained sand of the Floral Formation. It is recharged by vertical groundwater flow through the overlying till and by lateral groundwater flow from the Strawberry Hills. The aquifer then discharges through springs and seeps on the east side of the South Saskatchewan River valley. At the observation well site the top of the aquifer is at about 11 metres below ground level or at an elevation of about 501 m.
WSA Saskatoon appears to be transitional between unconfined (water table) and confined conditions. The hydrograph’s lowest point of about 498.2 metres occurred at the beginning of 1968 shortly after monitoring began. Following that water levels rose to 499 metres by the fall of 1972 and fluctuated between 499 and 500 metres until 2005. During this period the water level was below the top of the aquifer placing it under unconfined conditions, so that changes in the rate of recharge and discharge were reflected by filling and emptying of the pore spaces in the sand and gravel of the aquifer. Following that, several years of strong recharge resulted in a strikingly different response in WSA Saskatoon. While prior to 2005 water levels in the well fluctuated within 1 metre range for over 30 years and the annual fluctuations were within 0.5 metres, in 2010 alone water levels increased by 3.5 metres. Some of this change may be due to the water level rising above 501 metres into the clay-rich till above the aquifer resulting in the aquifer becoming fully confined. A layer of till occurs near the top of the aquifer at an elevation of about 498 to about 500 metres. This till layer may also have some influence on the transition from confined to unconfined conditions.
The outskirts of the City of Saskatoon have expanded and are now very near WSA Saskatoon. The water-level record for this well is therefore likely to be increasingly affected by urbanization, including deep storm sewers and leaking water and sewage lines.
WSA Saskatoon yields water of the calcium/magnesium-sulphate type with a Total Dissolved Solids concentration of approximately 3140 mg/L.