Fraser Valley – 2020 continues to be baffling. June has been such a wet month, that as of June 28, there were no wildfires burning in BC ( that were known. In 2020 , there have been 177 wildfires in BC (665 hectares burned). The 10-year average is 338 fires and around 25,000 hectares burned.
That’s the good news.
Now reality.
The River Forecast Centre is maintaining a High Streamflow Advisory for:
- Fraser River including the mainstem from Prince George through Hope and the Fraser Valley
The combined influences of seasonal snowmelt and rainfall across the Thompson and Fraser watersheds this month and last week has led to high flow conditions in the Fraser River.
Most recent observations are:
- Fraser River at Shelley (08KB001) peaked at 4,000 m3/s (between 5-year and 10-year flow) near noon on Friday and is slowly receding. The current flow is 3,760 m3/s
- Fraser River near Marguerite (08MC018) peaked at 5,700 m3/s (between a 5-year and 10-year flow) at noon on Saturday and is slowly receding. The current flow is 5,540 m3/s
- Fraser River above Texas Creek (08MF040) peaked early this morning at 6,590 m3/s (between a 5-year and 10-year flow) and is still at that level
- Thompson River near Spences Bridge (08LF051) is flowing at 3400 m3/s (between a 5-year and 10-year flow) and gradually rising
- Fraser River at Hope (08MF005) is flowing at approximately 10,400 m3/s (between a 5-year and 10-year flow) and beginning to level off
- Harrison Lake near Harrison Hot Springs has a water level of 12.09 m. It has risen approximately 20-cm over the past 2-days
- Fraser River at Mission (08MH024) is at approximately 11,500 m3/s and the water level is 5.84 m
Warm and wet weather last week in the upper reaches of the Fraser River watershed has increased snowmelt runoff across the basin. Moderate rises through the lower reaches of the Fraser River occurred. The Fraser River at Hope has reached the highest flow of the season at 10,400 m3/s, between a 5-year and 10-year flow and appears to be leveling off. The Fraser River at Mission water level is at 5.84 m and modeling predicts the river could reach 5.96 m on Monday morning.
Based on the weather forecast for the upcoming week, expect flows to level off and begin to gradually recede for the Fraser River at Hope and at Mission. However, the river is vulnerable to a localized heavy rainfall in the Lower Fraser that could increase flows from local tributaries like the Chilliwack River, Harrison River and Coquihalla River. If another heavy rainfall event occurs in the headwaters of the Upper Fraser, Cariboo and North Thompson it would take approximately 3-5 days for that pulse of water to eventually peak flows in the Lower Fraser Valley. Weather forecasts show continued unsettled weather patterns for the upcoming week.
There is little expectation for the Lower Fraser River to reach substantial flood levels (gauge level at Mission > 6.4 m or flow at Fraser River at Hope > 11,000m3/s). However, since the river is flowing at the highest level recorded this season thus far, it is vulnerable to any heavy basin-wide rainfall event over the next two weeks.
