Excessive phosphorus (TP) and nitrogen (TN) inputs from the Red–Assiniboine River Basin (RARB) have been linked to eutrophication of Lake Winnipeg. It is important for the management of water resources to understand where and from what sources these nutrients originate, in order to manage these sources and improve the quality of the receiving waters.
At the request of the International Souris River and Red River Boards, the Commission undertook the development and binational application of a SPARROW model for the Red-Assiniboine basin nutrient loading estimation. The RARB straddles the Canada–United States border and includes portions of Saskatchewan and Manitoba in Canada, and North and South Dakota and Minnesota in the United States. This represents the first binational application of SPARROW models to estimate loads and sources of TP and TN by jurisdiction and basin at multiple spatial scales.
The model now has been calibrated and has been consistently applied to the full Red-Assiniboine basin after three years of intensive work that was supported by government partner agencies in both Canada and the U.S. (Jenkinson and Benoy, 2015). This model enables all jurisdictions to better understand water quality dynamics and nutrient loading in this important transboundary basin.
A map made using this model would show the distribution of the total phosphorous or nitrogen deposited into a waterbody by sub-watershed, here the Red and Assiniboine rivers and their tributaries. In theory, a user could see which sub-watersheds are the culprits for pollution. A quick Google Maps search or an analysis of the surrounding environment could explain why the results show up the way they do. Figure 3 shows those areas in the basin that have the highest phosphorus yields and therefore where reduction efforts could be effectively focused. Based on the model, it is estimated that about two-thirds of the phosphorus loading that comes from the Red River into Lake Winnipeg originates in the U.S. portion of the basin. It is becoming increasingly clear that a binational solution is required to address this environmental issue.
The International Red River Board is planning to use the results from the model in support of its basin-wide nutrient management strategy to encourage all impacted jurisdictions to use this information in working towards solutions to help reduce nutrient loading. This modelling work is unique, as it marks the first time that there has been full binational collaboration in the development and application of a common regional water quality model to a transboundary basin in North America.
These results can be further explored with the interactive mapper.
Partners - Acknowledgements
SPARROW Modelling has been a partner driven endeavour.
The major partners were the International Joint Commission (IJC), particularly the International Watersheds Initiative (IWI), and the Wisconsin Water Science Centre at the United States Geological Survey (USGS). Staff at several federal and provincial agencies also contributed their expertise and data to the project: Craig Johnston and Donna Myers (USGS), Richard Burcher and Martin Serrer (National Research Council), Erika Klyszejko and Craig McCrimmon (Environment and Climate Change Canada; Erika now works for the International Joint Commission), Jason Vanrobaeys (Agriculture and Agri-Food Canada), Elaine Page and Justin Shead (Manitoba Conservation and Water Stewardship) and Pam Minifie and Ondiveerapan Thirunavukkarasu (Saskatchewan Water Security Agency). Michael Laitta and Ted Yuzyk from the IJC’s Hydrographic Data Harmonization Task Force set the context for this binational model application. The Red-Assiniboine project was suggested by the IJC’s Red River and International Souris River Boards.