The high amount of rain forecast by Environment Canada for the upper parts of the Rideau Valley Watershed for the remainder of the week could cause all water levels and flows to increase rapidly, and possibly cause localized or minor flooding in small waterways, urban areas and ditches.
"We know that the water levels for the most part across the watershed are below normal, so it's likely it will be brought up to above normal for a short period of time before they recede again" due to the expected rainfall, said Rideau Valley Conservation Authority (RVCA) manger of engineering services Brian Stratton.
The forecast comes as the nearby Cataraqui Conservation authority, anticipating no such significant rainfall, worsened its low water condition.
The Rideau Valley Watershed is currently maintaining a minor low water condition because of a drier-than-normal August. The RVCA has been fighting the low water levels since June, despite some rain throughout the month of July, said Stratton.
"We're in a good situation to handle this big rainfall because we've had a deficit of rain over the last several months, so getting this big rain (will) probably saturate the soil," added Stratton.
He says if the watershed was experiencing wetter conditions, a possible heavy rainfall like the one forecast could possibly lead to more significant widespread flooding.
Stratton said the larger bodies of water like the Jock River and Rideau River probably won't be affected by the significant rainfall, as they can handle the extra water without flooding on the ridges. However, the smaller waterways and ditches may see some minor flooding.
Environment Canada has revised the forecast and the watershed area now could receive rainfall amounts of 40 to 60 mm throughout Wednesday and into early Friday morning.
This is slightly less than what was originally predicted on Wednesday morning. Environment Canada originally forecast the watershed could receive rainfall amounts of 60 to 90 mm, with a few areas possibly exceeding 100 mm of rain.
"We don't see that amount of rain every day in our area so that's a pretty big storm," said Stratton, adding that, even with the revised forecast, it is still a significant amount of rain.
The RVCA is reminding people who live in the watershed to protect their properties and themselves by exercising caution around all bodies of water and ensuring their sump pumps are in working condition, as well as keeping ditches, culverts and storm drains clear of obstructions.
Jessica Munro, Local Journalism Initiative Reporter, Brockville Recorder and Times