Authorities in southern Alberta will be conducting a sweep of a pair of rivers in an effort to recover any remains that may have entered the water at some point.

Between September 29 and 30, the RCMP, along with the help of local police and fire services, will be searching the Bow and Saskatchewan Rivers in Calgary, as well as the districts of Lethbridge and Medicine Hat.

The search will begin with an aerial sweep of the area by the RCMP helicopter along the Bow River from south of the City of Calgary to the Saskatchewan border. The Oldman River will also be surveyed to the City of Lethbridge at this time.

The Calgary Police Service will also be using HAWC to conduct a search of the Bow River within city limits, starting at the Bearspaw Dam in the northwest and then continuing south all the way to Calgary’s southern limit.

If anything is spotted during the aerial search, teams with CFD Aquatic Rescue, along with police, will investigate further.

Investigators say that this search is not specifically aimed at any particular missing persons’ case, but may provide answers in the 27 missing persons reported to the RCMP whose cases remain open.

Lethbridge Police say they are four historic missing persons’ cases where they believe the Oldman River could be involved.

Meanwhile, Calgary police say they have five missing persons' cases that could involve the Bow River. Of those, they are pretty confident that three missing people have gone into the water at some point.

“The search is not for a specific individual but it is a sad reality that some people voluntarily enter or fall into the dangerous waters of the river and are unable to get themselves out,” says Cst. Lynn MacDonald with the CPS Missing Persons Team in a release. “In conducting the search, we hope to be able to bring some answers to families that have missing loved ones.”

Police say they have chosen this period of time because the waters of the main rivers are at their lowest level and are the clearest, to provide the best conditions for personnel involved.

If any bodies are recovered, police investigators will work with the Medical Examiner’s Office to identify the victim and ensure that no crime is involved with their death.