The Manitoba government is taking another step in its battle against zebra mussels at the St. Malo Reservoir. A partial drawdown of the reservoir began last week and is still underway, according to the province’s Environment and Climate Change Water Stewardship branch. The move is part of an ongoing response plan to suppress the invasive species, which were first detected in the reservoir last year. Officials had hoped to start treatment in the fall of 2024, but high-water inflows and cold weather forced them to postpone. Then this fall, the province began lowering the reservoir. The draining began last week, on September 22, 2025. The plan is to bring the water level down about three metres, roughly 10 feet, below full supply. Once that level is reached, water will be held steady for one to three days while staff observe conditions before letting the reservoir refill ahead of winter freeze-up. Government staff are on site during the process to keep an eye on shoreline stability; watch for stranded fish or wildlife, and look for signs of adult zebra mussels. Property owners around the reservoir were advised to secure or remove docks and watercraft ahead of the drawdown. The province also noted that higher water outflow from the St. Malo dam will raise levels downstream in the Rat River, but said flows are expected to stay within the riverbanks. As of September 29, officials said the drawdown was still in progress and observations were being made. More information on the results is expected in a couple of weeks. Residents with questions can contact the Aquatic Invasive Species Unit by email at AIS@gov.mb.ca or by phone at (204) 793-1154. *All photos in the gallery below are courtesy of Tracy Reimer, St Malo resident.