Flood Warnings and Advisories

High Streamflow Advisory – BC Interior
ISSUED: 4:30 PM April 25, 2018

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

  • South Interior
  • Boundary
  • Kootenay
  • Central Interior

A ridge of high pressure is building across British Columbia, ushering in the first prolonged warmer weather period of the freshet season. Temperatures are expected to gradually rise through Friday, with temperatures expected to reach in the low to high 20s throughout most of the BC Interior.
Snow pack observations at automated snow weather stations across the province have shown snow accumulation up until the past few days, and at higher elevations (above approximately 1500-1600m), much of the forecasted heat will translate into ripening the snow pack. At low-to-mid elevations (approximately 900-1500m) snow packs have ripened, and are now experiencing snowmelt. With warming over the next few days, the melt of these low-to-mid elevation areas is expected to accelerate. Current weather forecasts are indicating the potential for an upper low system to transition to wetter weather, particularly for south-east BC.
While it is still too early in the snow melt season for significant flows in the larger river systems of the province, smaller streams and tributaries that are fed by low-to-mid elevation terrain are at the greatest risk of high flows over the next several days. These areas include:

  • Okanagan - including tributaries in the Oliver, Osoyoos, Summerland, Penticton, Kelowna, Vernon and surrounding areas
  • Similkameen - including the Tulameen and tributaries
  • Boundary - including the West Kettle River, Kettle River, Granby River and surrounding tributaries
  • Kootenay - including the Moyie River and mid-elevation tributaries in the Castlegar, Trail, Salmo, Creston, Cranbrook and surrounding areas
  • Central Interior – including the Bonaparte River, Salmon River (around Falkland), West Road River, Baker Creek,  and tributary flows around Merritt, Cache Creek, Quesnel, Williams Lake and surrounding areas (some of these areas have experienced extensive forest fires in 2017 which may exacerbate high flows)

Some of these regions have been experiencing high flows already this season, and runoff is expected to increase. Other areas have yet to experience significant flows yet this season. Snow packs are extreme in many of these regions, with increased flood risk due to the significant amounts of water that are available for runoff.
The River Forecast Centre will continue to monitor conditions and update this advisory as conditions warrant.

Contact:
Media relations,
Ministry of Forests, Lands, Natural Resource Operations and Rural Development
Tel: 250 356-7506

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.
  2. Flood Watch: River levels are rising and will approach or may exceed bankfull. Flooding of areas adjacent to affected rivers may occur.
  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.

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