Flood Warnings and Advisories - River Forecast Centre - Province of British Columbia

Flood Warnings and Advisories

Flood Warning – Boundary
Flood Watch – Kootenay (UPGRADED)
UPDATED: 1000h May 15th, 2018

The following Flood Warnings, Watches and Advisories in the South-East region are in effect as of Tuesday May 15, 1000hr:

  • Flood Warning – Boundary, including the Kettle River, West Kettle River, Granby River and surrounding tributaries
  • Flood Watch – West Kootenay (UPGRADED), East Kootenay (UPGRADED)

High temperatures over the past three days has led to increased snow melt rates, and higher runoff. Another day of hot temperatures is expected on Tuesday. An upper low is forecast to bring increased chances of showers on Wednesday, and rainfall on Thursday and into Friday. Generally, precipitation amounts forecast at this time are in the 10-15mm range, with the possibility of localized amounts in the 20-30mm range.

Snowpacks are dwindling at mid-elevation and south-facing aspects, with approximately 30-35% of snow remaining at the Moyie Mountain and Greyback Reservoir automated snow weather stations. At higher elevations, 60-90% of the annual snowpack remains.

In the Boundary, including the Kettle River, West Kettle River and Granby River, snow in the mid-to-upper elevations is critical for potential flooding. High melt rates over the past 3 days indicate that there is on-going risk for rising river levels from snowmelt this week. In the Kootenay, rivers are more strongly influenced from mid-to-upper elevations, and rivers have been experiencing significant rises.

There are increased risks for flood conditions through the region with rapid snowmelt and rainfall later this week. Rapid rises are expected throughout the region on Thursday and Friday. On the Kettle and Granby Rivers, rises are expected to be near, or possibly above flows experienced last week, with the critical period for these flows being the Friday to Saturday period. In the Kootenay, rivers are expected to reach above flows experienced so far this season, with significant risk of flooding in the Slocan River, Salmo River, Moyie River, as well as other tributary river systems throughout the Kootenay.

A summary of conditions as of 0900h Tuesday May 15th:

  • Kettle River near Westbridge (08NN026) is flowing at 320 m3/s (10-year flow) and rising. Currently forecasting the potential for flows in the 400-500 m3/s range on Friday into Saturday, and peak levels will depend on the amount of rain the watershed receives
  • Granby River at Grand Forks (08NN002) is flowing at approximately 320 m3/s (5-year to 10-year flow) and rising. Currently forecasting the potential for flows in the 400-500 m3/s range on Friday into Saturday, and peak levels will depend on the amount of rain the watershed receives
  • Slocan River near Crescent Valley (08NJ013) is currently flowing at 430 m3/s and rising. Currently forecasting the potential for flows in the 600-800 m3/s range into Saturday, and peak levels will depend on the amount of rain the watershed receives
  • Salmo River near Salmo (08NE074) is currently flowing at (2-year flow) and rising. Currently forecasting the potential for flows in the 400-500 m3/s range over Friday- Saturday, and peak levels will depend on the amount of rain the watershed receives

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