Two conservation authorities in the Ottawa region have issued flood watches as warm weather, coupled with rain and melting snow, could trigger some flooding.

The Rideau Valley Conservation Authority (RVCA) issued a flood watch on Monday, saying that by late Tuesday afternoon or evening, "water levels in some locations are expected to reach the stage at which flooding of local roadways begins."

"Residents of the community of Hilly Lane in North Grenville Township can expect to see their access road submerged by [Tuesday] evening," a media release issued Monday said. "River levels will continue to rise through the early hours of Wednesday morning, and the depth of water will quite likely make the road impassable by typical passenger vehicles by the daylight hours."

Ice removal on the lower Rideau River was delayed because of cold weather throughout March, the RVCA says.

"The river is open from Rideau Falls to Highway 417, but an ice sheet remains in place on sections of the river between Highway 417 and Bronson Avenue. Where the ice sheet remains in place, water levels will be somewhat higher compared to ice-free conditions."

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The RVCA says river levels are expected to hold through Wednesday due to cooler temperatures, "but can be expected to increase further later in the week as a result of warm temperatures and rain in the forecast for Thursday." (Sean Kilpatrick/Canadian Press)

The authority also says there's a possibility of ice jams forming if the remaining ice breaks up.

"In the event of an ice jam, water levels will rise rapidly and quite possibly to flood stage in flood vulnerable communities.

The South Nation Conservation Authority, which covers a large area east and south of Ottawa, issued a flood watch on Sunday. The authority says severe flooding is not a concern at this time, but that residents may see what it calls "nuisance flooding" in low-lying areas.

The potential for blocked storm drains, catch basins and culverts is high.

The high on Monday is expected to reach 12 C, with the possibility of up to 25 millimetres of rain falling in 48 hours, starting Monday night.