It’s always good to remember that the watershed is more than just the piece we can see when we look at the lake.  Every drop of water that falls inside the watershed that doesn’t evaporate will eventually go down the Betsie River to Lake Michigan at Frankfort.  Within that area are a number of lakes that are quite different.  Most lakes have water coming in and going out.  When measured, a “flushing rate” can be determined which means how long it takes to have the volume of water in the lake replaced by incoming water. Duck Lake has a “flushing rate” of 1.9 year, Green Lake is 2 years but Crystal Lake is over 20 years,  (What happens in Crystal stays in Crystal!). Very little water is coming in and very little going out.  The surrounding wetlands and springs make a big difference for Green and Duck lakes.  If you know the land surrounding Crystal Lake you know there are almost no wetlands around it and just one stream flowing into it.  All are in the same watershed but are quite different lakes.