Flood Warnings and Advisories

High Streamflow Advisory – South Coast and Vancouver Island - Issued: 2:45 PM April 6, 2023

The River Forecast Centre is issuing a High Streamflow Advisory for the South Coast and Vancouver Island including:

  • North Shore Mountains
  • Howe Sound
  • Lower Mainland and Fraser Valley
  • Vancouver Island

Weather Synopsis:
A series of frontal systems are expected to pass across British Columbia over the Easter long weekend. Moderate to heavy rainfall is expected on Thursday evening into Friday, and again on Sunday into Monday. Model forecasts are indicating up to 200 mm, and potentially more over higher terrain, of precipitation over the next four days. Temperatures are expected to warm during this period, which may lead to snowmelt in lower and mid-elevation snowpacks.

River Conditions:
Rivers are expected to rise in response to rainfall, with high flows expected across Vancouver Island and the South Coast. Flows are expected to be high on Friday and may ease into Saturday before rising again Sunday and into Monday. Current forecasts are indicating the potential for localized flooding in low-lying areas. Hydrologic modelling is indicating the potential for flows in the 2-year to 5-year range on Central and Southern Vancouver Island (including Sproat River/Somass River, Chemainus River and approaching flood stage on the Englishman River); similar flows are possible in rivers throughout the region.

Current river levels are extremely low in most areas; conditions are expected to be dynamic throughout the weekend with periods of rapid river rises. Fast-flowing rivers pose increased risk to life safety.

The River Forecast Centre continues to monitor the conditions and will provide updates as conditions warrant.
For information on how to prepare for flood hazards, visit PreparedBC .

BC River Forecast Centre

Ministry of Forests

Contact for Media Relations, Ministry of Forests:
Tel:  778-698-8453

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