WINNIPEG - March 4, 2010 - Just before 7:00 am today, a widespread electric power interruption caused low water pressure for homes and businesses throughout Winnipeg. Water pressure remained above minimum standard for most of Winnipeg, but did fall below the standard for about one minute at the outlying reaches of Winnipeg. Pressure returned to the normal operating range within 10 minutes.

Electric power was lost to the three pumping stations that deliver water to homes and businesses – McPhillips Pumping Station, which supplies water to northwest Winnipeg, MacLean Pumping Station which supplies water to east Winnipeg, and Hurst Pumping Station which supplies water to southwest Winnipeg.

Power was also lost at the new City of Winnipeg Drinking Water Treatment Plant in Springfield. However, sufficient storage of treated water was within the reservoirs, so the supply of treated water to customers was maintained without interruption.

The City supplies about 350 million litres of water per day during times of peak water use (e.g., in the morning when residents are getting ready for work and school). The backup natural gas system kicked into operation, but since the electric power interruption occurred during peak water time, the water supply dropped to about 100 million litres per day.

The water system continues to experience power surges and interruptions, however backup systems are operating. Since water use is lower during the day, significant water pressure fluctuations are not occurring.

The City experienced a similar low water pressure event during a high demand period due to a power interruption on January 18, 2010. Our water system was designed to function with a reliable power supply, with backup systems to respond to limited power failures, and has functioned well for decades. However, it was not designed to meet peak demand when wide-scale power interruptions affect all three pumping stations simultaneously.

The City completed a water pumping reliability study in August 2007. The objective of that study was to assess and recommend improvements to water pumping reliability. Since then, a back-up battery power supply was installed for our automated water control system at a cost of about $300,000. Another $3.75 million is in the capital program for other improvements, including the installation in 2011 of a quick restart system for the pumps at all three stations.

Since the electric power interruption and the periods of reduced water pressure are brief, there is no disruption to wastewater treatment.