Date: Feb 16, 2018
GRCA Flood Message #1 - Flood Warning
The Grand River Conservation Authority is issuing the following combined Flood Watch and Flood Warning message.
A warm front is forecast to move into the Grand River watershed on Monday and persist through Wednesday next week. Daytime temperatures are forecast to reach 6 degrees on Monday, February 19th and 12 degrees on Tuesday, February 20th based on current forecasts. Overnight temperatures on Monday are expected to remain at 6 degrees overnight. Rain is forecast to begin Monday and continue into Tuesday bringing up to 40mm of rainfall across the watershed. The combination of warm temperatures and rainfall are expected to trigger moderate runoff into the river system.
These conditions are expected to result in snow melt and elevated flows in rivers and streams across the watershed. The combination of snowmelt and rainfall is expected to push river levels higher, resulting in minor flooding in low lying areas typically prone to flooding. It is expected that runoff will cause current ice in the river to break up. Break up of this ice may add to current stable ice jams in place in the Grand River through the Village of Conestogo, City of Cambridge, City of Brantford and community of Cayuga. A small ice jam is also in place downstream of the community of Plattsville on the Nith River. It is not possible to predict if ice jams will release during this event however the potential for flooding at the location of these ice jams exists.
The major reservoirs at Belwood, Conestogo, Guelph, Luther, Woolwich, Laurel, and Shades are at low winter holding levels and have storage available to manage runoff from this event.
Flood Watch
- Entire Watershed: Risk of flooding exists in low lying areas and from ice jams as this event moves through the watershed. Residents in areas typically prone to flooding should be aware of these conditions and take appropriate precautions.
- Grand River: The flood co-ordinator for Grand Valley should monitor conditions along the Grand River and be prepared to close Hwy 25 and warn residents as needed.
- Conestogo River: The flood co-ordinator for Woolwich Township should monitor conditions and prepare to close the low level bridge upstream of St. Jacobs at 1505 Three Bridge Road on Monday, February 19th.
Flood Warning
This event has the potential to create ice jams flooding in the communities of Cambridge, Brantford and Cayuga. Given the potential for ice jam flooding, a Flood Warning is being issued for the following communities:
- City of Cambridge: City of Cambridge flood co-ordinators are asked to warn residents in the floodplain in the Blair area, adjacent to the Grand River, and the Speed River area downstream of the King Street bridge in Preston. Potential for ice jam flooding exists into the middle of next week as a result of this event. City of Cambridge flood co-ordinators are also asked to monitor and be prepared to close Blackbridge Road at the Speed River.
- City of Brantford: City of Brantford flood co-ordinators are asked to maintain the closure of Gilkison Street and monitor conditions through the dike reach through Thursday.
- Town of Cayuga: Haldimand County flood co-ordinators are asked to warn residents in the floodplain in the Town of Cayuga of the potential for ice jam flooding next week, beginning Monday evening through Thursday.
GRCA Ice Fishing
It is expected that ice fishing at GRCA lakes and reservoir offering the activity will be suspended in response to increased flows into the reservoir and uncertain ice conditions. Anyone planning a visit is advised to call the parks directly for an update on current conditions.
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 noon on Thursday, February 22, 2018. Updated flood messages will be issued as conditions develop and better forecast information becomes available.