Water report warns of mounting pressure on local ecosystems

Tashi Farmilo

The newly released Portrait global de l’eau 2025 offers a sobering look at the state of freshwater across Quebec, with several findings that resonate deeply in the Outaouais region. Published by the Ministry of the Environment, the report highlights declining water quality, biodiversity loss, and the growing impacts of climate change—all playing out in lakes, rivers, and wetlands that define much of life in the Pontiac and Outaouais.

One of the most concerning examples lies in the watersheds that flow into the Ottawa River. The Rivière Noire, which runs through Waltham, and the Petite rivière Rouge, near Chénéville, both received poor ratings for water quality. According to the report, these rivers are heavily affected by agricultural activity—namely, runoff containing phosphorus, nitrates, and faecal coliforms from corn and soya farming, livestock manure, and insufficiently protected streambanks. Both rivers are part of the larger Petite-Nation and Coulonge watershed groups, which the province lists among the sectors under "very high pressure" due to cumulative human activity.

The region’s lakes aren’t faring much better. Lac Simon, located in Duhamel, is flagged as one of the 16 lakes in Quebec with recurring cyanobacterial blooms. Sampling in the lake revealed high phosphorus concentrations during the summer months—levels that pose risks to both aquatic life and recreational use. Lac Leslie, in Otter Lake, is also cited as having poor water quality, particularly due to phosphorus enrichment tied to shoreline development and watershed disturbance.

Climate stress is no longer theoretical. The report documents summer water shortages in Shawville and Mansfield-et-Pontefract in 2020, 2021, and 2023. These shortages are linked to extended dry spells, more frequent heat waves, and aging water supply infrastructure. According to monitoring data, several small systems in the region are already approaching critical thresholds for availability during drought years.

Biodiversity trends are equally grim. The map turtle, which depends on undisturbed sandbanks along the Ottawa River, is listed as “vulnerable.” The Hickorynut mussel, a species once abundant in the river, has seen sharp declines, attributed to damming and water pollution. The Outaouais is identified as one of the zones where aquatic biodiversity is under the most pressure, particularly from shoreline degradation, increased water temperatures, and invasive species.

Yet not all news is bleak. The report highlights successful restoration efforts along the Coulonge River, coordinated by the watershed group OBV RPNS (Organisme de bassins versants des rivières du Pontiac, du Nord-Est et de la Serpent) in partnership with local community members. These initiatives have led to measurable improvements in riverbank stability and fish habitat. Through actions such as planting native vegetation, removing invasive species, and reinforcing vulnerable shorelines, the group has delivered what the Ministry calls a model for low-cost, community-driven watershed restoration.

What emerges from the Portrait global de l’eau 2025 is clear: local waters are in trouble, but recovery is within reach. As the report puts it, “The health of water in Quebec will depend on a collective ability to recognise its value and to act accordingly.”