GRCA Flood Message #1 – Combined Flood Watch and Watershed Conditions – Water Safety

The Grand River Conservation Authority (GRCA) is issuing a Flood Watch message for Nith River Subwatershed and a Watershed Conditions – Water Safety message for the remainder of the Grand River watershed remains in effect.

Weather forecast

A low-pressure system originating in the American Midwest is expected to affect the Grand River Watershed beginning late Sunday morning, December 28th, 2025. The system is forecast to bring temperatures of 5–6°C along with 30–40 mm of rainfall.

The watershed previously received 5–10 mm of precipitation as freezing rain and snow on Friday, December 26th, 2025. In addition, the northern and central portions of the watershed currently contain an estimated 30–60 mm of water equivalent in the snowpack, resulting from snowfall earlier in December.

Flood Watch for Nith River Subwatershed

The Grand River Conservation Authority is issuing a Flood Watch message for the Nith River Subwatershed due to expected runoff from potential snowmelt and rain on Sunday evening and Monday morning. Higher flows in local waterways combined with runoff from this event will increase the risk of flooding in low-lying areas typically prone to flooding.  In particular, municipal flood coordinators in New Hamburg and Ayr should be aware of these conditions and take appropriate precautions.

The Watershed Conditions – Water Safety message issued on December 9th 2025 remains in effect for the reminder of the Grand River Watershed.

GRCA Reservoirs

The major reservoirs at Belwood, Conestogo, Guelph, Luther, Woolwich, Laurel, and Shade’s are at normal levels for this time of year and have storage available to help reduce the impact of downstream flooding.

Stay safe 

High flows and unstable ice conditions will increase the safety risk around rivers and streams throughout the watershed. The public is encouraged to exercise extreme caution around local waterways. Parents are reminded to keep their children and pets away from watercourses. The public is reminded to stay off ice-covered waterbodies, due to unsafe conditions. 

River conditions and forecasts are being monitored closely, and any additional flood messages will be issued as needed.

This message will remain in effect until 12 p.m. on Friday, January 2nd, 2026. 

More information

• For more information on flows, weather and reservoir conditions see the River Data section of the GRCA website.
• 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 X at grca_flood_msg.
• More information about how the GRCA’s role in managing floods is available in the Flooding section of the website.
• Copies of the GRCA’s River Safety Rules booklet is available by contacting the GRCA Administration Centre

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Media Contacts:

Serena Catania, GRCA Supervisor of Communications and Marketing
Phone (519) 621-2763 x2240  |  Email scatania@grandriver.ca