Water Supply and Treatment

Nanaimo's water supply and treatment system is well-developed and carefully managed to ensure a sustainable and clean water source for the community. Our mandate is to provide and sustain an adequate supply of good clean water, now and into the future. This is made possible through the development and use of programs that include long-range planning, system operation, system maintenance and capital works.   The mains goals of the City’s water resource are to:

• Plan for continued population growth,
• Help protect the environment,
• Manage aging infrastructure and,
• Build resilience to climate change and emergencies. 

The City’s water comes from the South Nanaimo River Watershed, covering over 200 square kilometers of catchment.  The City of Nanaimo owns and operates two water supply dams that store water to ensure consistency of supply throughout the year and release water to maintain the environmental health of the river.  The highest dam, Jump Lake, impounds approximately seventeen million cubic meters of water and provides active storage, meaning that the level fluctuates over the course of the year.  The lower dam, South Fork, impounds approximately two million cubic meters of water.  The City’s water intake is at the South Fork Dam and the water level at the dam is maintained to provide a consistent level and supply pressure to the South Fork Water Treatment Plant.

Strict access limitations and a partnership with Mosaic Forest Management helps protect the watershed from human contamination and other pollutants.

Self Sustaining Operation:

Nanaimo’s first public water system began just five years after the City was incorporated when, in 1879, the Vancouver Coal Company built the first wooden pipes to deliver water to the public from a spring on Wesley Street.  Significant progress was made when the City acquired water licenses for the Nanaimo River and built the South Fork Dam in 1930, setting a new benchmark for the public water utility. The concrete arch dam, which measures 50 meters across, stands 30 meters high and retains nearly 2 million cubic meters of water in South Fork Lake.

Nine balancing reservoirs are located throughout the city to meet peak domestic demand and emergency fire flows. Emergency fire flows can exceed supply system capacity and draw reservoirs down for several hours. To serve the growing north end of the city, the first balancing reservoir was constructed at Lost Lake in 1969, followed by reservoirs at College Park and Rutherford Road. Additional reservoirs and pipelines were built at Duke Point Industrial Park, Langara Drive, and Tanya Drive to meet heavy growth in the 1980’s.

In addition, snow-pack and rainfall information is monitored by two automated measuring systems located in the watershed. This information is used to forecast stream flows and regulate the floodgates for summer storage. Overall, Nanaimo's water management system reflects a proactive approach to ensure a sustainable, clean water supply for both current and future needs.