GRCA monitoring network - Upper Grand River

Caution: Data is provisional. For more information read our Data Terms of Use

Interpreting the lines

The numbers on the left of the graph will change depending on the flows in the last seven days. Here are some significant flow rates to help you interpret current conditions.

• Learn how ice jams can cause sudden changes in the flow rates and lead to flooding.

How to read this graph

This graph contains information on flows in the Grand River during the last week at various gauge locations. The graph is automatically updated every hour.

Along the bottom (x axis) are the days the data was recorded. The vertical line above the date represents midnight.

Along the left (y axis) is the river flow measured in cubic metres per second (m3/s). That shows the amount of water passing by the gauge at that time. A cubic metre is 1,000 litres of water so a flow of 10 m3/s would represent 10,000 litres of water per second.

Please note: A number of factors will influence the accuracy of the data including:

• backwater from ice, weeds or debris,
• malfunctioning equipment and/or routine maintenance of equipment may cause data spikes, and
• sediment accumulation which may plug the gauge intake.

For more information read our Data Terms of Use