The City of Winnipeg operates three large treatment plants to treat millions of litres of wastewater that is collected through a vast network of sewer pipes from homes, businesses and industries. Sewage and other liquid wastes which make up wastewater, are processed in the plants and released as treated effluent to the Assiniboine and Red rivers, which merge and flow into Lake Winnipeg. The City has continually upgraded the three treatment plants since they were built to keep pace with city growth and changing regulatory standards. Over the next 20 years, it will invest hundreds of millions of dollars to reduce nutrient (nitrogen and phosphorus) and bacteria (fecal coliform) levels in final effluent to meet the levels specified in the Provincial Environment Act.

Stormwater
The City has a stormwater system made up of drains, pipes, and culverts that carry rainfall and snowmelt to the rivers. During heavy rainstorms, the runoff, flows down the street and drains into catch basins or storm drains. Some catch basins direct the runoff to pipes that drain into retention ponds (also known as stormwater retention basins or man-made lakes). These retention ponds, an efficient and cost-effective land drainage system, also benefit the environment by acting as a natural filter - they remove sediment and chemicals before the water drains to the rivers.

Shoal Lake
The Shoal Lake watershed (Figure 1.1) straddles the Manitoba–Ontario border at an approximate latitude of 49.5_N. It is part of the larger Rainy River–Lake of the Woods–Winnipeg River drainage basin. The total area of the watershed (including its lakes and streams) is approximately 960 km@. Fifty--four percent (54%) of the watershed area is located in Ontario and 46% in Manitoba1. The three lakes of greatest significance in the watershed are Shoal Lake, Falcon Lake and High Lake. Shoal Lake is the largest of the watershed’s three lakes with a surface area of about 260 km2.

The lake has an estimated average depth of 9 m, but incorporates many shallower embayments such as Indian Bay, Snowshoe Bay and Clytie Bay in its northern portions.

The Shoal Lake watershed is part of the Boreal Forest Region as well as part of the Lake of the Woods ecoregion.

It is more closely identified with the warmer and more humid southeastern mixed forest region than with the colder and drier boreal regions to the north. It typically experiences warm summers and cold winters. The mean annual temperature is approximately 1.5_C, with a mean summer temperature of 15_C and mean winter temperature of –13_C.Mean annual precipitation is in the range of 600 millimetres. - Shoal Lake Watershed Management Plan

Shoal Lake Aqueduct
This 155 km (97mile) reinforced concrete aqueduct, "noted among the world's greatest engineering works" provides Winnipeg with water form Shoal Lake on the Manitoba-Ontario border, by gravity flow. It was completed in 1919 and a 19km (12mile) branch was added in 1960.

To facilitate construction, the greater Winnipeg Water District Railway was built and completed in 1914. This 168km (105 mile) railway remained self-sufficient for many years, hauling sand and gravel and transporting passengers. Today it remains the only means of access to the intake at Shoal Lake.National History Committee of the CSCE


On April 5, 1919, Winnipeggers turned on their taps and began to enjoy the first fresh water flowing from the Shoal Lake Aqueduct. Getting clean, safe and abundant drinking water was a problem at the turn of the century. Private operators like the Winnipeg Water Works Company supplied water drawn right out of the Assiniboine River taken from the current site of the Cornish Library. But the water from the Assiniboine got worse and worse showing high faecal bacteria counts even then. The result was relatively high death rates from Red River fever in 1904, when Winnipeg set a world record of 19.4 deaths per 1000. Starting in 1906, water was pumped from a system of artesian wells. But the water was very hard and not abundant enough. The search was on for a better supply.George Siamandas - Winnipeg Stories

Impact of Climate Change
Much of the useable freshwater in Western Canada comes from the snow and ice fields of the Rockies. At the mouth of the Saskatchewan River, 87% of the flow is meltwater from the icy peaks of the Rocky Mountains.

Glaciers are receding and thinning as the climate warms. River and stream flows will drop significantly without input from the huge glacial storehouses of freshwater. Already, flows in the major rivers of the western prairies have been reduced to 20-70% of their historic flows.

Rains replenish Prairie rivers, wetlands and lakes. However, summer precipitation declines of up to 10% to 20% are forecasted for Manitoba. At the same time, average temperatures are projected to rise, increasing the rate of evaporation from existing water bodies. Droughts may become even more common. The loss in winter runoff may be offset by increases in springtime precipitation. Manitoba is projected to experience a 20% increase in springtime rainfall. However, problems occur when spring rains fall too quickly, causing floods