The Grand River Conservation Authority has issued a combined Flood Warning/Flood Watch message.
A weather system is expected to bring mild temperatures and rain across the Grand River watershed on Thursday and Friday which is expected to melt much of the snow pack, resulting in increased runoff into local waterways.
Some local waterways also have intact ice sheets, which may break up and shift during this event, increasing the risk of ice jam flooding.
Runoff will result in flooding in low lying areas typically prone to spring flooding.
River flows are expected to peak Friday in Drayton, Grand Valley and New Hamburg.
There is the potential for ice jams in Grand Valley, New Hamburg, West Montrose, Brantford, Six Nations Territory, Cayuga and Port Maitland.
Ice jams can occur quickly and without warning.
Residents in areas prone to ice jams should prepare accordingly.
Conditions will be monitored closely.
A Flood Warning is being issued for:
- Nith River (New Hamburg & Ayr): Flows in the Nith River through New Hamburg are expected to peak on Friday afternoon based on the current forecast. Flows are expected to peak late Saturday morning in Ayr. Municipal Flood Coordinators are advised to warn residents in Warning Zone 1.
A Flood Watch is being issued for:
- Grand River (Grand Valley): Flood coordinators in Grand Valley are advised to monitor conditions and prepare to close Highway 25 through Grand Valley.
- Grand River (West Montrose): Flows in the Grand River through West Montrose are expected to increase, peaking in Warning Zone 1 on Friday morning. Flood coordinators are advised to monitor conditions due to the increased potential for ice jams and prepare to warn residents as needed.
- Nith River (New Hamburg & Ayr): Flood coordinators are advised to monitor conditions and prepare to warn residents in Warning Zone 2 as needed.
- Conestogo River (Drayton): Flows in the upper Conestogo River are expected to peak at Warning Zone 1 in Drayton early Friday morning. Flood coordinators are advised to monitor conditions and prepare to warn residents as needed.
- Conestogo River (St. Jacobs): Flood coordinators in Woolwich Township are advised to monitor and prepare to close the low level bridge at 1505 Three Bridges Road on Thursday afternoon.
- Speed River (City of Cambridge): Flood coordinators in the City of Cambridge are advised to monitor and prepare to close Blackbridge Road at the Speed River on Friday.
- Grand River (City of Brantford and Six Nations): Flows are expected to peak in the Grand River through the City of Brantford on Friday evening. There is an ice jam located between the Cockshutt Bridge and Onandaga which will increase the risk of additional ice jams and flooding in low lying areas through this reach. Flood coordinators in the City of Brantford are advised to close Gilkison Street. Six Nations and County of Brant flood coordinators are advised to monitor and prepare to close Boundary Road and 4th Line.
- Grand River (Caledonia and Cayuga): River ice remains present in the southern Grand River. Potential for ice jams is possible in low lying areas typically prone to flooding. Flood coordinators are advised to monitor conditions along River Drive (south of Caledonia), Sims Lock Road, Grand Sports Road as well as the communities of Cayuga and Port Maitland.
GRCA’s major reservoirs at Belwood, Conestogo, Guelph, Luther, Woolwich, Laurel, and Shade’s Mills are being used to store runoff from this event and reduce flooding downstream of these reservoirs.