Flood Warnings and Advisories

Flood Warning – North Coast – Kitimat/Terrace/Kemano (UPGRADED)
Flood Watch – North Coast – Other Areas, Haida Gwaii
High Streamflow Advisory – North Coast (Nass/Stewart)
ISSUED: October 24, 2017 10:00 AM

As of 10:00 AM the River Forecast Centre is issuing or maintaining the following warnings and advisories:

• Flood Warning (UPGRADED)- North Coast including the Kitimat River, Little Wedeene River, Kemano River, Hirsch Creek and other rivers and creeks in the Kitimat, Terrace, Kemano and surrounding area
• Flood Watch – North Coast including areas around Prince Rupert and Highway 16 west of Terrace
• Flood Watch (NEW)- Haida Gwaii including rivers and creeks on Graham Island and Moresby Island
• High Streamflow Advisory (NEW) – North Coast including the Nass River and Stewart

Heavy rain is expected to continue today through the region as an intense frontal system is expected to develop. Rainfall totals since yesterday have been in the 40-80 mm range, with the heaviest amounts in areas around Kitimat, Terrace, and Kemano.

This rain has led to rapidly rising river levels overnight, and most of the Water Survey of Canada gauged rivers in the region are currently reporting flows in the 2-year to 5-year return period range. The Kitimat River below Hirsch Creek (WSC 08FF001) is flowing at 1865 m3/s (approaching a 5-year flow). Hirsch Creek near the mouth (WSC08FF002) is flowing at approximately 480 m3/s (5-year flow)

Additional heavy rainfall is expected to continue through Tuesday, with additional amounts in the 30-100 mm range, or more, expected by the end of the day. Areas around Kitimat are currently forecast to see the highest amounts of additional rainfall.

While some rivers may see a brief reprieve in rises in the early part of Tuesday, additional rises are expected on Tuesday afternoon and overnight. Current hydrologic modelling is indicating the potential for flows on the Kitimat River below Hirsch Creek to reach up to near record levels (above 3000 m3/s). Extremely high flows are expected throughout the Kitimat through Terrace corridor.

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.