Research conducted by the University of Manitoba and Agriculture and Agrifood Canada indicates agriculture accounts for a small percentage of the phosphorus that ends up in Manitoba’s waterways. The majority of phosphorus that ends up in Lake Winnipeg originates from the Red River system. Of the total load of phosphorus coming into the province, 60% was coming from the U.S. and other jurisdictions and 40% was generated in Manitoba itself. Of the 40%, approximately equal proportions could be attributed to urban sources, agricultural sources and natural sources. The ratio will change depending on the flow in any particular year with the proportion from urban sources being higher during low flow years and the proportion from agricultural and natural sources being higher in high flow years.