The Grand River Conservatory Authority is urging frequent Grand River users to be more cautious as high river flows can pose a hazard.

A flood watch for Waterloo Region's rivers has been extended until noon Saturday by the Grand River Conservation Authority (GRCA).

In a statement, the authority wrote Thursday, that warmer temperatures over the next few days will melt the rest of the snow in the upper part of the watershed, leading to higher water levels and faster flows on the Grand, Conestogo, Nith and Speed Rivers.

A "large weather system" is also expected to move into the area on Saturday night and stay for a few days, and could bring as much as 50mm of rain, adding to river levels.

In detail, here are the specific warnings from the GRCA for each river in the area:

Grand River in Grand Valley and Waldemar

Some road flooding in Grand Valley and Waldemar is possible overnight on Thursday, with low-lying areas around County Road 25 and Ninth Line at risk of flooding.  

Conestogo River in St. Jacobs

The bridge across the Conestogo river on Three Bridges Road upstream of St. Jacobs is closed due to high water levels until further notice. 

Nith River in New Hamburg and Ayr

Water levels in the Nith River are expected to rise in New Hamburg overnight Thursday and in Ayr on Friday evening.  

Speed River in Cambridge

The Black Bridge and the walking trail under Highway 401 are closed until further notice. 

Grand River in Brant County and Six Nations

Six Nations Fourth Line at Bateman Line is closed because of high water levels until further notice. 

Grand River in Haldimand County

The river level will keep rising in the southern part of the watershed for the next two days, and flooding may be possible in Grand Sports Driver, south of York.