The water supply for the Cities of Regina and Moose Jaw, and surrounding regions, comes from Buffalo Pound Lake, which is a a shallow reservoir in the Qu’Appelle Valley. The lake is 29 km long, 1 km wide, with an average depth of only 3 metres. The surface area of Buffalo Pound Lake is 2900 hectares, which means at “full supply level” it has a capacity of 90 million cubic metres.
Water levels in Buffalo Pound Lake are controlled by the Saskatchewan Water Security Agency, which manages the release of water into Buffalo Pound Lake from the Qu’Appelle Dam on Lake Diefenbaker. Typically1 to 2 cubic metres per second of water are released into Buffalo Pound Lake annually, which means average residence time of water in the lake can range between eighteen to thirty-six months. Very little water enters Buffalo Pound Lake from rain or spring runoff except in abnormally wet years.
Buffalo Pound Lake is generally free of industrial pollution but is naturally rich in nutrients (phosphate, nitrogen and dissolved organic carbon) which encourage the growth of phytoplankton (typically diatoms in the winter and green algae or cyanobacteria in the summer). Weed growth can also be extensive. Algae and weeds pose many treatment challenges such as high chemical demands and undesirable tastes or odours. The lake and watershed appear to also be impacted by ground waters infusing minerals.
All of this means the Buffalo Pound Water Treatment Plant plays a critical role in enabling the Cities of Regina and Moose Jaw and surrounding regions to provide high quality, safe water to their residents in the quantity required by those residents.