Lake depth is one of the easiest topics on this list to generalize. When looking at the depth of the lake, deeper is always better. Before I speak of the positives of a deeper lake, I will talk about the one negative. Deeper lakes are generally cooler than shallow lakes. In Northern Wisconsin the temperature between lakes does not vary by a huge amount, but there is some variation so it is good to know that the deeper lakes will be colder.
There are many benefits to a deeper lake. One major benefit in Northern Wisconsin is weed control. Weeds generally grow in warm, shallow water. If you choose a lake that is mostly less than 15 feet deep you run the risk of the lake being overtaken by weeds. Weeds rarely grow in water over 15 feet deep so if a lake has an average depth of over 15 feet, you can sure there won't ever be a takeover.Another benefit to a deep lake is volume. A deep lake has more room for fish and fresh water than a shallow lake. It also has more room for energy created from boats moving through the water (waves) to disperse so the effect on the shoreline is not as destructive. Another advantage of deeper water is protection for your boat. Many lower units have been torn off boats on big lakes that are shallow and have tree stumps just below the surface of the water.
Another reason a deep lake is better is that it will still be usable in times of drought. There have been quite a few lakes in Northern Wisconsin that have been rendered nearly useless in years of severe drought. While water level is also affected by the type of lake, it is something to keep in the back of your mind.
When considering the depth of a lake, it is important to know the average depth and what percentage of the lake is shallow. A lake can be 1000 acres of 4 foot deep water with a 1 acre hole that is 40 feet deep and the depth of the lake would be listed at as 40 feet, which is misleading. That is why you will find average depth listed for every lake on this site.