RVCASince the 1970s, numerous studies have been undertaken with a view to protecting the Rideau River’s value as an important natural and cultural heritage resource in Eastern Ontario and the greater Ottawa area.

Early efforts focused on water quality and the impact of urban pollutant sources on swimming beaches, progressing from the treatment of point sources such as combined sewer overflows, to non point sources such as urban runoff. These studies led to the adoption of a non-degradation policy aimed at controlling further runoff-borne bacterial loading, and the construction of stormwater treatment facilities for any new urban developments contributing runoff to the river and its tributaries.

Water quality in the Ottawa River basin is considered good overall as a result of the high velocity of the water and the numerous wastewater treatment plants that have been established. Most problem areas are localized, such as around densely urbanized areas. The Ottawa River’s many tributaries affect the overall water quality of the river itself. Despite localized problems, the majority of the Ottawa River is considered suitable for recreational uses such as swimming and fishing.

Click here - Gatineau Gatineau River, the largest tributary of the Ottawa, drains an area with only a small portion of dense, industrial landuse. For this reason, the river is generally of excellent quality. Nevertheless, the impact of human activities there is undeniable.

The Gatineau River has two water quality sampling stations run by the Ministère du Développement durable, de l’Environnement et des Parcs. Those stations are still active and samples are taken every month. The first station is located in Grand Remous (station 04080223 on the map), Bridge Highway 117, and the second between the Gatineau sector and the municipality of Chelsea, on the Alonzo-Wright bridge (station 04080003).

The water sampled at Grand-Remous could be argued to be close to the water quality found at the source of the Gatineau River since there is very little permanent housing upstream from this point.

Adapté de Portrait du bassin versant de la rivière Gatineau publié par COMGA

Lièvre WatershedLievre River. Source: COBALIUntil 1993 the practice of floating logs down the Lièvre River was big business. Unfortunately, as the logs floated in the water the residue of wood and bark began to break down - this had a detrimental effect on the river's water quality as it increased the biochemical oxygen demand (BOD), i.e. it reduced the concentration of oxygen in the water.

Wood and bark are made of organic substances (lignin and tannin) and nutrients (nitrogen and phosphorus). The tannins and lignin cause the water to become dark (a yellow-brown colour) in some places where there are a lot of logs.

However, the effects and impact of these organic substances on the water quality are difficult to quantify. In 2002, the Advisory Committee on managing the Lièvre River (CCGRL) organized an initiative to harvesting the floating logs which remain in the river. 150 cords of wood were removed from the river in the Val-des-Bois area, in St. Aimé-du-Lac-des-Iles. Not all of the logs were removed, and many remain at the bottom of the river and on the shoreline.

South Nation RiverEastern Ontario’s South Nation Watershed is a highly productive agricultural region of the province. However, in some cases, nutrient and bacterial contamination of the South Nation River and its tributaries has been linked to agricultural activities. Understanding the origins of these pollutants is critical to determining the agricultural management practices required to improve water quality in the watershed.

Water quality in the South Nation Watershed is reduced in many areas, while agricultural and urban
pressures continue to increase. Problems include direct cattle access to creeks and brooks, and manure runoff from fields which can lead to fecal contamination of water resources.