Rideau WatershedOn average 926mm of precipitation falls in the Rideau River Watershed each year. 60% of this precipitation is used by plants and trees or goes back to the atmosphere. The remaining 40% of the precipitation either flows into the rivers and streams or infiltrates into the ground and may eventually reach the groundwater table and recharge the aquifers or moves underground downstream to eventually discharge back to streams and rivers.

Rideau WatershedSurface water gauges collect water level data and stream flow data on rivers, creeks, and lakes. Level data is typically collected on lakes and reservoirs. Flows are collected where rating curves have been established on rivers and creeks.

Traditionally stormwater management has been involved in controlling the flow of water from peak flow events. Stormwater management has evolved into a more integrated approach that includes development policies, environmental goals, water quality and other aspects. Stormwater management is related to watershed and subwatershed planning which investigate the natural functions and features of the watershed.

Rideau WatershedIn 2005 parts of the Rideau Watershed  received very little precipitation during the months of July and August. This resulted in very dry conditions that had a negative impact on agricultural operations and crop yields. Water levels in reservoir lakes were at lower levels than normal for the time of year, and the many local streams that feed the lakes and larger

Rideau WatershedVegetative cover performs important functions in the watershed by reducing erosion, stabilizing the hydrological cycle and maintaining a balance between surface water and groundwater. It improves air quality by taking up carbon dioxide and producing oxygen.

Rideau WatershedThe water demand in the watershed is fairly consistent, however the supply varies day to day, month to month and year to year. Supply will also vary throughout the watershed depending on climate, landcover and topography.