Over the years I have been fly fishing I have seen cases where people take chances by trying to cross a river, fish in area's where the river current is very strong. Always find out as much as you can about the area before trying something that you not sure of.
As in most outdoor sports, safety is an issue. Fly Fishing is no different. Whether you are fishing from a boat or wading, water flow is probably the most important piece of information you will need to make your fishing experience safe and more enjoyable. There are several ways to find out how much water is being released from the dams. You can see a website (Swedish) and get latest levels water is being released at the time. In order to get future release information you can go to any one of several web sites to get release information for the day. My advice would be to call one of the local fly shops or accommodations that are located on the river and ask about water flows for the day so you can make an informed decision about where you can fish safely.
When you have made your choice about where to fish, there are a few other safety guidelines you will need to follow.
As a beginner you shouldn’t wade in more than knee deep water with a smooth gravel bottom. It’s not necessary to wade in waist deep water to catch fish. I have caught many very nice fish in water that no more than a 1/2 meter deep.