Flood Warnings and Advisories

High Streamflow Advisory – Fraser River (NEW)
ISSUED: 12:30 PM June 26th, 2020

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

  • Fraser River including the mainstem from Prince George through Hope and the Fraser Valley

The 2019-20 snow season was a relatively high year for many regions of the Fraser River basin, including the Upper Fraser East, Cariboo Mountains, North Thompson and South Thompson.  Snowmelt began in mid-April, bumping the Fraser River at Hope to above normal flows since April 20th.  Favourable weather conditions have spread the melt of this high snow pack throughout the whole freshet season, and the Fraser River at Hope did not rapidly peak as it did in 2018.  Persistent precipitation across the watershed has maintained flows at a fairly high level (>7,000 m3/s) since May 20th.  Recent warm weather followed by moderate to heavy precipitation in the headwaters of the Fraser River (Robson Valley, North Thompson, South Thompson) on Tuesday and Wednesday resulted in significant increases in upstream tributaries.  

Harrison Lake has been increasing substantially over the past week, contributing additional flow to the Lower Fraser Valley.  The Fraser River at Mission water level is at 5.65 m as of Friday morning, the highest water level of 2020 so far.
Current observations as of Friday, June 26 at 11:00 PDT:

  • Fraser River at Shelley (08KB001) is currently peaking at 4000 m3/s (between 5-year and 10-year flow)
  • Fraser River near Marguerite (08MC018) is flowing at 5580 m3/s (between 5-year and 10-year flow) and rising
  • Fraser River above Texas Creek (08MF040) is flowing at 6290 m3/s (5-year flow) and rising
  • Fraser River at Hope (08MF005) is flowing at approximately 9900 m3/s (between a 2-year and 5-year flow) and rising
  • Fraser River at Mission (08MH024) is at approximately 11,000 m3/s and the water level is 5.65 m

Warm and wet weather earlier this week has increased snowmelt runoff across the basin. Moderate rises through the lower reaches of the Fraser River are expected to continue into the weekend.   Over the weekend, moderate showers and risk of thunderstorms are forecast for most of the Fraser Basin.  The Lower Fraser Valley could experience showers as the peak pulse flowing from the Upper Fraser River passes through the Lower Fraser River on Sunday. CLEVER forecasts could be slightly under forecasting this peak if heavier rainfall occurs than currently forecast. Current modelling is indicating the potential for flows in the 10,100 to 10,500 m3/s range at Hope (Mission gauge level of approximately 6.0 m) over the weekend.  Note:  The Lower Fraser River model (link below) was not finished by the time of issuing of the High Streamflow Advisory.

There is little expectation for the Lower Fraser River to reach substantial flood levels (gauge level at Mission > 6.4 m).  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.

The Ministry of Forests, Lands, Natural Resource Operations and Rural Development produces 10-day Lower Fraser River Water Level Forecasting and results are available at: http://bcrfc.env.gov.bc.ca/freshet/lower_fraser/LFR-10-DayFloodLevelForecasts.pdf

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 situation and provides updates as conditions warrant.

Contact for Media Relations, Ministry of Forests, Lands, Natural Resource Operations and Rural Development:
Tel: 250-213-8172

Levels of Warnings/Advisories:

  1. High Streamflow Advisory: River levels are rising or expected to rise rapidly, but that no major flooding is expected. Minor flooding in low-lying areas is possible. This is the lowest level.
  2. Flood Watch: River levels are rising and will approach or may exceed bankfull. Flooding of areas adjacent to affected rivers may occur. This is the intermediate level.
  3. Flood Warning: River levels have exceeded bankfull or will exceed bankfull imminently, and that flooding of areas adjacent to the rivers affected will result. This is the highest level.

Links:

  1. Home of River Forecast Centre
  2. Current Streamflow Conditions and Flood Forecast Modeling
  3. Map of Current Streamflow Return Periods for All WSC Stations
  4. CLEVER Model 10-day Forecasts of Discharges and Return Periods
  5. COFFEE Model 5-day Forecasts of Discharges and Return Periods
  6. Back to page of Flood Warnings and Advisories