Groundwater study, Rivers area, Manitoba
Bostock, Charles Alexander
The Rivers area is located in southwest Manitoba between 49Â°53' and 50Â°09' North Latitude and 100Â°04' and 100Â°29' West Longitude. The average precipitation is about 19 inches, and the mean annual temperature is about 35ÂºF. The surficial sediment is glacial drift. It overlies the Riding Mountain Formation throughout the area. A large aquifer bearing artesian water, containing about 2000 ppm. total dissolved solids, mainly sodium sulphate, occurs in the northwest part of the area beneath till and overlying or near the surface of the bedrock. Intratill sands and gravels in the north half of the area yield limited quantities of water of various qualities, ranging up to 4000 ppm. total dissolved solids, mainly calcium-magnesium sulphate. A large outwash delta occurs in the south central part of the area. It yields good quality water in generally minor quantities. Its water contains typically less than 500 ppm., mainly calcium-magnesium bicarbonate. Some of the delta water collects in the fluvial deposits in the north side of the Assiniboine River valley, just south of the delta where this water is presumably available in larger quantities. The Assiniboine and Minnedosa River waters generally contain between 600 and 1000 ppm. total dissolved solids, but may drop to as low as 370 in April and May. The main constituents are calcium-magnesium sulphate and calcium and magnesium bicarbonate. Water quality fluctuations observed in the Assiniboine and Minnedosa River waters as well as in one groundwater well, appear to indicate that recharge to groundwater from snowmelt begins in late January and February.