A new rainfall advisory is warning residents of High River to brace for heavy rain in the area this long weekend. 

Alberta's Foothills are expecting 25-40 millimetres of rain by Monday evening, which will increase the volume and speed of the Highwood River and its tributaries.

If the area gets 30 millimetres of rain, the Highwood River flow rate would increase to 126 cubic metres per second.

That's still significantly less than what was seen during last year's flooding, when other rivers like the Bow in Calgary and Sheep in Okotoks reached peak flow rates of 1,740 and 1,000 cubic metres per second, respectively.

Anyone — such as campers, fishermen, boaters and the general public — who are situated close to the river are advised to be cautious of rising water levels. 

High River flood

Flooding, which was spurred on by heavy rainfall, devastated High River last June. The town, which is south of Calgary, issued a rainfall advisory for this long weekend and is warning residents that heavy rains are possible in the area. (Jordan Verlage/Canadian Press)

The Town of High River is requesting that people stay off the rivers and away from the banks for their personal safety.

High groundwater is also a concern for officials and they are warning residents to make sure their sump pump systems are working and downspouts and eaves troughs are functioning.

Residents may also consider moving valuables and important documents in basements to higher locations.

If they haven't already done so, residents are being encouraged to register for High River's ALERT system.

Other areas under warning as well

High River isn't the only area being warned about possible heavy rainfall.

Environment Canada has issued a special weather statement for much of western Alberta — from Claresholm up to Grande Cache.

Meteorologists are predicting anywhere between 30-75 millimetres of rain from Airdrie north to Grande Cache, but some areas could see up to 100 millimetres.

The heaviest rain is expected to fall in the Nordegg and Rocky Mountain House areas.

For the mountain parks, current forecasts predict about 25-40 millimetres of rain by Monday evening.

However, there is still uncertainty in tracking the low pressure system bringing the rain and it's possible those areas could see 50 millimetres or more.