GRCA - Flood Watch - Entire Grand River Watershed

Flood Message #4: Flood Warning – Southern Grand River watershed – Lake Erie Shoreline | Flood Watch – Entire Grand River watershed

The Grand River Conservation Authority is issuing the following Flood Warning message for the southern Grand River watershed and Flood Watch for the entire Grand River watershed. This message replaces Flood Messages #3.

The flood peak from the weather system affecting the Grand River watershed earlier this week has reached Lake Erie. Flows in the southern Grand River remain high. Flooding of low lying areas downstream of Brantford, through Dunnville, continue where ice jams in the river are backing up water and causing localized flooding.

A new weather system is forecast to move into the watershed late Thursday afternoon and continue into Friday morning. This weather system is forecast to bring warm temperatures and rain. Air temperatures are forecast to rise above freezing late Thursday afternoon, rising to 11 degrees by midnight before falling back below freezing early Friday morning. Light rain will begin falling late this afternoon and continue into the early morning hours. Forecast rainfall accumulations are in the 5-10 mm range across the watershed. Higher rainfall amounts are possible if localized thunderstorms develop within this weather system.

The incoming weather event is expected to melt all remaining snow. The melting snow combined with additional rainfall and saturated ground conditions will result in runoff into local waterways. Based on the current forecast, river flows are expected to peak below levels experienced earlier this week. Flows are expected to remain within riverbanks except in locations where ice jams are causing localized flooding.

The warm weather has the potential to cause remaining ice jams in the southern Grand River to further weaken. This may cause the ice sheet to release upstream of Caledonia Dam creating the potential for ice jams to form downstream and cause flooding in the community of Cayuga.

A southwest wind will accompany the incoming weather event. The Ministry of Natural Resources and Forestry storm surge forecast for Lake Erie is indicating Lake Erie levels will surge early Friday morning, peaking just below the warning threshold for Lake Erie, decreasing by late Friday morning.

• Flood Watch – Entire Grand River watershed: A Flood Watch is in effect for the entire Grand River watershed. Municipal flood co-ordinators should aware of the incoming weather event and be ready to respond if called upon.
• Flood Warning - Southern Grand River watershed and Lake Erie shoreline (Haldimand County): In coordination with Haldimand County flood co-ordinators, a request has been made to the Canadian Coast Guard for an ice breaker to clear ice at the mouth of the Grand River in Port Maitland. Flood co-ordinators in Haldimand County are asked to warn residents in the floodplain in the community of Cayuga to prepare for potential ice jam flooding. There is potential for the ice sheet to release upstream of Caledonia Dam. If this occurs it is likely to result in ice jam flooding in the community of Cayuga. Haldimand county staff are requested to monitoring the Lake Erie shoreline areas in the lake Erie Flood Zone 1 and respond if needed to Lake Erie flooding.

GRCA’s major reservoirs at Belwood, Conestogo, Guelph, Luther, Woolwich, Laurel, and Shade’s Mills continue to be used to manage runoff from this event and reduce flooding downstream of these reservoirs.

Stay Safe

The public is reminded to exercise extreme caution around all water bodies. Banks adjacent to rivers and creeks are very slippery at this time and, when combined with current weather conditions, pose a serious hazard. Parents are encouraged to keep their children and pets away from all watercourses and off frozen water bodies, which will be weakened as a result of the warming trend.

This message will remain in effect until 4:00 p.m. on Friday February 8, 2019.  Updated flood messages will be issued as conditions develop and better forecast information becomes available.

More information

• For more information on flows, weather and reservoir conditions see the River Data section of the GRCA website.
• Safety information for parents and children is available in the GRCA’s River Safety Rules booklet.
• More information on the flood warning system is available on the GRCA website.
• Receive GRCA flood messages by e-mail by subscribing through the GRCA website.
• Follow GRCA flood messages on Twitter at grca_flood_msg.
• More information about how the GRCA manages floods is available in the Flooding section of the website.

-30-

Media contacts:

Cam Linwood, GRCA Communications Coordinator
Phone 519-621-2763 x2251  |  Email clinwood@grandriver.ca

Lisa Stocco, GRCA Manager of Communications
Phone 519-621-2763 x2316  |  Email lstocco@grandriver.ca

Read this news update on our website

View more Grand Actions newsletter notifications.
View more All news releases notifications.
View more The Grand newsletter notifications.