The flood of 2010 was particularly devastating for the Bella Coola Valley, but occurred in fall not spring (photo submitted)

The flood of 2010 was particularly devastating for the Bella Coola Valley, but occurred in fall not spring (photo submitted)

Spring flooding a risk as Bella Coola snowpack at 36% above normal

Weather in the next few months will determine flood conditions

This year’s long winter has resulted in record level snowpacks not seen in some areas in more than 50 years. The latest data from the B.C. River Forecast Centre indicates that the Bella Coola area snowpack is 36 per cent above normal, making the area one of the highest at risk for flooding in the province.

“The snowpack for the Central Coast as of March 1st is 136 per cent of normal (36 per cent above normal), which is one of the highest in the province,” said Jonathan Boyd Hydrologist, BC River Forecast Centre. “A snowpack that is 36 per cent above average increases the risk of flooding in the spring, but it is not necessarily the cause of flooding.”

The Bella Coola region is at risk of flooding in the fall/winter due to heavy rainfall events and larger rivers may be susceptible to flooding in the spring time due to snowmelt. Boyd said that the risk of flooding is dependent on the weather over the next few months, with a particular weather pattern being the worst case scenario.

“Weather conditions over the following three months will dictate if flooding does or does not occur,” said Boyd. “The worst-case scenario is a high snowpack, very cool and wet March and April, followed by an extended period of incredibly hot weather for five to 10 days in May to rapidly melt the snow, then having a significant rainfall event occur during the high flows.”

Local Emergency Management Coordinator Jessica Miller said they are continuing to prioritize preparedness activities.

“From an emergency management perspective, we are prioritizing preparedness activities including reviewing the current emergency plans and updating key contact lists, training and exercising with staff and leadership (CCRD board members, Chief and Council, and Stataltmc), increasing engagement (radio, bulletin boards, CCRD website and facebook, newsletters),” said Miller. “We’re working on a few projects as well including an alerting system and enhancing safety on Highway 20 especially between 4mile and downtown. We receive provincial updates through seasonal readiness meetings (next one happening this week and I’ll be attending), and directly from emergency management BC, BC River Forecast Centre and Environment Canada.”

Miller said there are many considerations for how the public can prepare for flood season, for example, move valuables to upper level floors at home and make sure electrical items are not in flood prone spots (figure out how to turn off your utilities), don’t walk or drive through flooded areas and stay away from high flow streams and waterways.

Across the province snowpacks are sitting at or above average everywhere, and the last times snowpack conditions were similar across those combinations of areas goes back to 1999, 1974 and 1972. The provincial average as of Mar. 1, 2020 is 111 per cent of normal.

The North and South Thompson are also at particular risk, and coupled with the increase also in the Upper Fraser has created a rare situation for the province. These areas are sitting at 120 and 135 per cent respectively.

Boyd said that there is “substantial flood risk” in the following areas:

  • Central Coast (Bella Coola)
  • Upper Fraser – West
  • Upper Fraser – East
  • Cariboo Mountains (Quesnel River)
  • North Thompson
  • South Thompson
  • West Kootenay
  • Boundary
  • Skagit basins

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Coast Mountain News