Jim, I didn't say folks just use chemicals, paying someone to clean the pond out is also "spending money" to keep the weeds out. You made my case, yours have been cleaned out.
My ponds were left by the ice age, we just made them a bit bigger. (dad and me, did dig one of them) My earliest picts/maps are from the 1800's and you can see the ponds there. They are all spring fed and quite a bit of water leaves them, we use to raise trout, they still have fish in them.
They also need to be cleaned out, you just can't get around the plant problem IF you live where it gets warm and there's daylight to feed the plants. That's why you see so many ponds that look "blue", folks are coloring the water trying to keep the sun from getting to the weeds and it doesn't take much sun.
Here's a little fun fact, over the years we have found arrow heads, a stone ax heads ect. along my stream so this was an area that Indians camped, hunted and fished a lot, right here. A few years ago, I found a stone spear point and from what I found online, it's approx. 2000 years old.
SR