Categories: HomeLocal NewsNews

Rivers could rise rapidly as heavy rains hit Lower Mainland

Streamflow runoff conditions are shifting due to the heavy rainfall soaking communities across the south coast.

A high streamflow advisory was issued by the River Forecast Centre on Sept. 23 when the first major rainstorms of the season kicked into high gear.

Localized flooding could be seen in some low-lying areas like Fraser Valley tributaries or the Chilliwack River, by Thursday or Friday, as river levels start to rise rapidly.

“These storms will mark a significant shift in streamflow runoff conditions which have been dominated by drier summer patterns for the past several weeks,” according to the advisory from the B.C. River Forecast Centre.

“Rivers are expected to rise rapidly in response to rainfall on Wednesday, with peak flows from the first storm expected late-Wednesday or Thursday, with larger rivers expected to reach peak levels later on Thursday or into Friday.”

Hydrologic modelling shows the potential for streamflow levels to reach the 2-year to 5-year flows in some areas which could lead to localized issues and minor flooding.

The first major rainstorms brought heavy rain in the 25-40 mm range for Vancouver Island, with amounts exceeding 100 mm over West Vancouver Island, and 30-50 mm for the South Coast with higher amounts in the mountains. Precipitation amounts for Sept. 23 were in the 20-100 mm range on West and North Vancouver Island, 15-55mm in Central (inland) and Eastern Vancouver Island, and 20-75mm in the Sunshine Coast, Howe Sound, North Shore Mountains and Sea-to-Sky corridor.

“Additional storm cycles into the weekend will bring additional periods of high streamflow; advisories will be updated to reflect anticipated conditions as we approach the weekend.”

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

  • North Shore Mountains
  • Metro Vancouver
  • Fraser Valley tributaries including the Chilliwack River
  • Central Vancouver Island
  • Eastern Vancouver Island
  • West Vancouver Island
  • North Vancouver Island
  • Sunshine Coast
  • Howe Sound and Sea-to-Sky including the Lillooet River

READ MORE: Previous streamflow advisory for Chilliwack River

READ MORE: Rivers rise when rains arrive with a vengeance


Do you have something to add to this story, or something else we should report on? Email:
jfeinberg@theprogress.com


@CHWKjourno
Like us on Facebook and follow us on Twitter.

Want to support local journalism during the pandemic? Make a donation here.

Jennifer Feinberg

Leave a Comment
Share
Published by
Jennifer Feinberg

Recent Posts

Kootenay Ford dealer’s frustration grows with ICBC

Trail AM Ford owner Dan Ashman says he just wants fair compensation from ICBC

33 mins ago

At least 26% of eligible voters have already cast a ballot, Elections BC says

Voters can cast a ballot until 8 p.m PST on Election Day

38 mins ago

PHOTOS: Assault in Maple Ridge sends three men to hospital

RCMP were called to a residence Tuesday night

48 mins ago

Human rights win in rainbow flag fight cost B.C. city $62,000

“Lengthy and involved” process provoked by complaint

48 mins ago

Public safety of residents cited as young bear euthanized in Chilliwack

Human-habituated bear was hanging around residential areas and bird feeders near the Vedder River

1 hour ago

OUR VIEW: Lenient courts aren’t helping

It’s hard to fault the palpable frustration of Metro Vancouver Transit Police

1 hour ago