Water is fundamental to human life and the ecosystems that support that life. The importance and value of water becomes especially significant in semi-arid southern Saskatchewan. As Saskatchewan grows and the climate changes, water availability will be a limitation for meeting social and environmental needs. The Saskatchewan Environmental Society (SES) continues to play an important role in planning and education around water issues.

In 2022, SES completed the first Depave Paradise event in Saskatchewan. Depave Paradise is an initiative of Green Communities Canada that turns disused asphalt spaces into new green spaces. Pavement and asphalt can be useful surfaces in cities for accessibility and durability; however, they also disrupt the natural water cycle. Hard and impermeable, asphalt does not allow water to filter into the ground. Instead, water slides across, picking up road salt, pesticides, and other contaminants. Replacing asphalt with green space means that more water will soak into the ground and be naturally filtered by soil and plants, also reducing flooding.

In the summer of 2020, the Saskatchewan government announced an immediate $4 billion to irrigate 500,000 acres (200,000 ha) of land from Lake Diefenbaker over a 10-year period, doubling the irrigable land in the province. The South Saskatchewan River represents the main reliable freshwater source for much of southern Saskatchewan. Urban centres like Regina, Moose Jaw and Saskatoon are totally dependent on the river for their water supply, and many smaller communities, farmers, industries and other water users also depend on the river. That is why SES called for an environmental impact assessment to consider the environmental consequences, economic impacts, and public policy ramifications of this hastily announced project.

In the summer of 2016, a rupture in a Husky Energy oil pipeline spilled as much as 250,000 litres of crude oil and diluent into the North Saskatchewan River. The contamination spanned 500 kilometres of the river, putting the drinking water of nearly 70,000 Saskatchewan residents at risk, and resulted in at least 150 reported wildlife deaths. The spill exposed a lax regulatory system governing oil pipelines in Saskatchewan. In an inclusive set of recommendations, SES called for 13 new oil pipeline safety measures for the Saskatchewan government to implement, to ensure better safeguards for our water.

SES also continues to press for cleanup of northern Saskatchewan watersheds contaminated by the operation of uranium mines. Even though some closed over 30 years ago, their legacy of contamination continues to this day.