1-in-100-year rainfall triggers flood, safety warnings for Churchill River in Sask.

Saskatchewan's Water Security Agency is warning people to use caution around waterways in the Churchill River basin after a massive rainfall on Monday.

The area in northern Saskatchewan has been experiencing record or near record wet conditions since mid-April, says the agency.

Buffalo Narrows, Sask., got 111.8 mm of rain on Monday, more than its average monthly rainfall for the entire month. Most of the rain fell within a 12-hour period. The Water Security Agency says it was in excess of a one in 100-year event.

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Flows on tributaries to the Churchill River are expected to increase over the next few days. Flows on the Churchill River itself, which were already at near-peak levels, are also expected to increase over the coming weeks.

There is the potential for flood damage at areas upstream of Patuanak, Sask., as the water level in the Churchill River there was near a 50-year high before Monday's rainfall.

The agency advises less experienced users to avoid the rivers in the Churchill basin altogether as deep, fast moving water can pose a serious hazard.