An Ecosystem Services Assessment of the Lake Winnipeg Watershed Phase 1 Report

The report applies an Integrated Management of Environmental Assets (IMEA) approach to evaluate the economic value of ecosystem services in southern Manitoba. It compares the current landscape, dominated by agriculture, with three reconstructed pre-settlement scenarios. The analysis finds that restoring natural environments, particularly forests and wetlands, could significantly increase annual ecosystem service values and provide cost-effective alternatives to hard infrastructure for water purification and climate regulation. The study highlights that nonpoint nutrient loading from agricultural runoff is a primary driver of Lake Winnipeg's eutrophication and argues that a balance between productive and natural landscapes is essential for the lake's health.

• Lake Winnipeg is identified as the most eutrophic of the world's largest freshwater lakes, with water quality degraded by human activities across a multi-jurisdictional watershed of approximately 950,000 km2.
• Nonpoint sources are responsible for approximately 75 to 90 per cent of the nutrient loads entering Lake Winnipeg, contrasting with Lake Erie, where point sources were the dominant cause of eutrophication.
• Manitoba is a major contributor to the lake's nutrient load, providing 47 per cent of total phosphorus and 49 per cent of total nitrogen loads, with the Red, Assiniboine, and Souris rivers accounting for 63 per cent of total phosphorus and 39 per cent of total nitrogen.
• The current landscape in southern Manitoba provides annual ecosystem service values (ESVs) between CDN$0.33 and 1.03 billion, while pre-settlement landscapes are estimated to provide between CDN$0.5 and 3.02 billion.
• Forests and wetlands are the most significant contributors to ESVs, accounting for 79 to 96 per cent of total values across the evaluated landscapes.
• Ecosystem services related to water quantity and quality and climate change are the most valuable, representing 74 to 91 per cent of total ESVs by contextual relevance.
• The conversion of native prairies, forests, and wetlands to agricultural land has been driven by over a century of socio-political policies aimed at expanding agriculture as the primary economic activity in southern Manitoba.
• Climate change is expected to exacerbate nutrient loads through more frequent extreme floods and droughts, while higher summer temperatures may increase the size and duration of algal blooms.
• Restoring natural environments can be a more cost-effective alternative to hard infrastructure; for example, wetlands can provide water treatment, flood prevention, carbon sequestration, and wildlife habitat.

APA

Voora, V., & Venema, H. D. (2008). An Ecosystem Services Assessment of the Lake Winnipeg Watershed Phase 1 Report. International Institute for Sustainable Development. https://www.iisd.org/system/files/publications/ecosystem_assessment_lake_wpg.pdf

Chicago

Voora, Vivek, and Henry David Venema. An Ecosystem Services Assessment of the Lake Winnipeg Watershed Phase 1 Report. International Institute for Sustainable Development, 2008. https://www.iisd.org/system/files/publications/ecosystem_assessment_lake_wpg.pdf.

Wikipedia

{{cite report |last1=Voora |first1=Vivek |last2=Venema |first2=Henry David |title=An Ecosystem Services Assessment of the Lake Winnipeg Watershed Phase 1 Report |publisher=International Institute for Sustainable Development |date=31 March 2008 |url=https://www.iisd.org/system/files/publications/ecosystem_assessment_lake_wpg.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{voora2008ecosystem, author = {Voora, Vivek and Venema, Henry David}, title = {{An Ecosystem Services Assessment of the Lake Winnipeg Watershed Phase 1 Report}}, institution = {International Institute for Sustainable Development}, year = {2008}, month = mar, url = {https://www.iisd.org/system/files/publications/ecosystem_assessment_lake_wpg.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }