Based on our cleanings along the North Saskatchewan River, we estimate, that there are 54 kg of wastes along one river kilometer! This amount is probably refreshed after each flood. Therefore we can say the river holds 54 kg/km and flood event. As a comparison, for example values found in Switzerland (Europe) range between 5 and 40 kg per river kilometer.

The composition of the wastes can be found in the picture below. Plastics (bags, sheets, cups) and clothes (pants, towels, shirts), which are sometimes made of plastic themselves (polyamides, polyesters) are far the largest group. They make more than three quarters of all found wastes. Scrap iron is dominant as well, caused by its heavy weight.

Sometimes we find several objects, which were too big and too heavy to be transported away, such as pieces of drainage pipes, barrels, bikes, dug in tires. We find often summer sleeping- places of homeless persons and teen's meeting points, where we find abandoned bags and trashes.

We investigated the waste composition along the Mill Creek in Edmonton. This small creek and its watershed is heavily used as a recreational area. No wonder, we found lots of wastes at the banks and in swells. We estimate a waste amount of 36 kg per river kilometer. We believe this amount is refreshed after each flood event.

The Mill Creek is approximately 4 km long, thus his riverbed would carry about 144 kg of waste per flood event! This number does not include waste in the remaining watershed containing trails and picnic areas.

The composition of the wastes can be seen below. Plastic and clothes are clearly dominating with nearly 70 %. The relatively high amount of aluminum cans and bottles represents the use of the area as a recreational zone.