UDPATE – High Streamflow Advisory – Fraser River
ISSUED: June 6, 2017 11:30 AM
The River Forecast Centre is maintaining a High Streamflow Advisory for Fraser River including areas of the main stem river from the Fraser Canyon downstream to the ocean
Flows on the Fraser River reached highs over the weekend, with flows at the Water Survey of Canada gauge Fraser River at Hope (08MF005) peaking at 9,800 m3/s, and water levels at the Fraser River at Mission (08MH024) reaching 5.65 m.
Upstream tributary flows have been receding, and river levels on the Fraser River downstream through Hope and the Fraser Valley to the ocean are expected to ease through this week. Flows at Hope are forecast to drop to approximately 8,000 m3/s by late this week or into the weekend.
Weather later this week is expected to transition in the BC Interior, with high pressure and warm temperatures early in the week being replaced by a large upper low pressure system by Wednesday-Thursday of this week, ushering in a steadier period of showers and rain. Runoff from this rainfall will lead to rises in tributary flows on the Fraser River, and another period of rising flows is expected through the Fraser Valley early next week. Current forecasting is indicating the potential for flows in the 9,000-10,000 m3/s range at Hope, and water levels at Mission of approximately 6.1m over the Tuesday to Thursday period next week (June 13-15). There is still some uncertainty over the amount of rain that will fall within the Upper Fraser River basin (e.g. upstream of Prince George) and the Thompson River system; flows along the lower Fraser River may be above or below the current forecasted levels depending on how much rain occurs.
The River Forecast Centre will continue to monitor river levels and will update the advisory as conditions warrant.
A High Streamflow Advisory means that river levels are rising or expected to rise rapidly, but that no major flooding is expected. Minor flooding in low-lying areas is possible.
A Flood Watch means that river levels are rising and will approach or may exceed bankfull. Flooding of areas adjacent to affected rivers may occur.
A Flood Warning means that river levels have exceeded bankfull or will exceed bankfull imminently, and that flooding of areas adjacent to the rivers affected will result.