Im with ya Cecil. Our 2nd largest lake in CT suffers from the same issue and our largest lake...candlewood use to be a go to spot for trolling big trout. That lake is pretty green most of the summer. Too much run off from fancy houses with the best lawns you've ever seen. Now its hard to tell if the lake actually stratifies or not. Use to be clear as day on the finder. Our second largest lake is further down the line to where deadly blue green algea blooms occur nearly every summer.
That's a shame. We too have yards like golf courses on some lakes here that have to be managed with fertilizer and herbicides. There is no way they are that perfect without. All our trout lakes have gone from native Cisco to the Cisco disappearing to not being able to support trout through the end of summer.
I was fishing a 7 mile long lake in Michigan on my vacation that is now overdeveloped too. What puzzles me is there is no way the soil can support a leech bed in conjunction with a septic tank as it's pretty much solid rock, stones, and gravel there, and many of the lots aren't much bigger than the houses. Considering a lot of the homes are now permanent I have to wonder how they are dealing with the sewage? Pumping frequently can get very expensive, but the cottage I stayed at had no place in the yard to pump out sewage as in a septic tank as far as could tell. OTOH they must be pumping as Michigan is pretty strict when it comes to the environment, at least I thought they were.
Sadly when I was in Maine I saw a lot of new building on lakes. At least I think you have to be 100 feet from the shoreline for new construction?