Flood Warnings and Advisories
Flood Warning - Somass River (UPGRADED)
ISSUED: November 26, 2017 10:30 AM
The River Forecast Centre is upgrading to a Flood Warning for:
- Somass River including Sproat River, Ash River and tributaries
A series of frontal systems have moved over Vancouver Island last week and this weekend, saturating the soil in this area and causing lake levels to increase considerably.
- The ASH RIVER BELOW MORAN CREEK (08HB023) is currently flowing at 230 m3/s, which is a 2-5 year return period flow, and is peaking now
- SPROAT RIVER NEAR ALBERNI (08HB008) is currently flowing at 250 m3/s, which is a 2-5 year return period flow, and is still rising
- SOMASS RIVER NEAR ALBERNI is currently estimated to be running at 785 m3/s, which is a 2-5 year return period flow and close to the 2015 flood level
Environment and Climate Change Canada (ECCC) forecasts about 10 mm rainfall for Port Alberni on each of Sunday and Monday and then 40 mm Tuesday. The current hydrologic modeling indicates that further rises equalling or exceeding 2016 levels for these three rivers are expected. The rivers are expected to peak on Monday.
The River Forecast Centre will continue to monitor conditions and update this advisory as conditions warrant.
A High Streamflow Advisory means that river levels are rising or expected to rise rapidly, but that no major flooding is expected. Minor flooding in low-lying areas is possible.
A Flood Watch means that river levels are rising and will approach or may exceed bankfull. Flooding of areas adjacent to affected rivers may occur.
A Flood Warning means that river levels have exceeded bankfull or will exceed bankfull imminently, and that flooding of areas adjacent to the rivers affected will result.