Before heading out to my favorite streams, I always take a look at the US Geological Survey website. http://www.usgs.gov/ Yesterday, my wife mentioned taking the kids out on a float trip. The first thing I mentioned was to check the river level and rate of flow. It had rained recently and quite a bit too.
You never know how fast the water may be running. I think it's a best bet to check out water levels and flow - even water temperature - depending on time of year - which can help if you are monitoring a spawn.
MAKE IT A POINT TO TELL YOUNG CHILDREN NOT TO DRINK THE WATER IN STREAMS. YOU NEVER KNOW WHAT IS FLOWING WITHIN THE STREAM.
Which reminds me, please do pay attention also to the lakes which note to watch out for possible high mercury levels.
SAFE WADING IN MURKY WATERS!!