High Streamflow Advisory – Nass River

Issued: 4:35 PM June 30^th, 2021

The River Forecast Centre is issuing a High Streamflow Advisory for:

• Nass River

Extremely hot weather has been affecting the entire province over the past week. Temperatures within the Nass watershed have been sufficiently high to spur snow melt at the highest elevations. Stewart Airport reached the following maximum temperatures; June 25: 22.9°C, June 26: 28.4°C, June 27: 30.5°C, June 28: 31.4°C, June 29: 26.2°C. According to Environment and Climate Change Canada, temperatures are forecast to cool down slightly reaching maximum temperatures of 20 to 25°C.

The Nass River above Shumal Creek (08DB001) reached approximately 4,000 m³/s (between 2-year and 5-year flow) around midnight last night. The river reached the highest level of the season on June 3^rd at approximately 5,000 m³/s (nearly a 10-year flow) and is currently not expected to reach that level again this year. The Nass River is forecast to recede over the upcoming forecast period. However, since flows are relatively high for this time of year, the river is vulnerable if a heavy rainfall event occurs.

Details of the CLEVER Model forecasts for this region can be found at: http://bcrfc.env.gov.bc.ca/freshet/map_clever.html

The public is advised to stay clear of the fast-flowing rivers and potentially unstable riverbanks during the high-streamflow period.

The River Forecast Centre continues to monitor the conditions and will provide updates as conditions warrant.