The Assiniboine–Red drainage region extends across southern Saskatchewan and Manitoba and includes both Regina and Winnipeg. Land used for agricultural production—arable land and natural land for pasture—accounted for 73.2% of the total area in 2011, followed by natural and semi-natural areas (23.7%) and built-up area (3.1%).
The drainage region had the highest fertilizer application area in the country at 74,969 km2, accounting for 63% of the region’s arable land in 2011. This drainage region also had the second highest density of linear infrastructure including roads, rail lines and transmission lines at 997.2 m/km2.
The population was 1,464,936 in 2011, with a population density of 8.1 persons/km2.
Surface freshwater intake from thermal-electric production, drinking water plants, irrigation, manufacturing and mining was 1,522.4 million m3 in 2013.
The average annual water yield was a relatively low 8.4 km3 over the period 1971 to 2013. The water yield per unit area was 0.04 m3/m2—the second lowest in the country. Monthly water flows peak in April. However, the monthly water variability index was the highest, meaning the volume of water supplied in each month can vary widely from year to year. Evapotranspiration was 0.39 m3/m2, compared to 0.23 m3/m2 at the Canada level.
Sources of nitrogen and phosphorus residuals in the environment include fertilizer application, livestock and poultry production, as well as industrial emissions. The residual nitrogen in agricultural soils normalized across the total area of the drainage region was the highest in the country at 1,822 kg/km2.
Turbidity levels of source water for drinking water plants were among the highest in the country at 7.7 nephelometric turbidity units (NTU) in 2013.