The ponds are filling up with debris from all of the grass, leaves, plant cuttings and dirt, etc. that washes into them. This is creating problems with the floating fountains resting on the bottoms and interfering with the pumping of the water. The little pond is so bad that the fountain no longer sprays water. The solutions are to either dredge the muck from the bottoms or raise the overflows and raise the level of the water, or to just let them do their job of filtering the runoff and stop trying to keep the algae from growing in them, give up the fountains, etc., and let them go wild.
In the big pond, raising the overflow height would cause the pond to really expand in size (as you can see in the photo) since the existing bank is very low on one side. It would also flood the plants growing at the upper end of the pond. The option to let them go wild could be helped by planting them with swamp trees, etc. No matter what is done, it will create a howl among some residents. My recommendation would be to let the ponds and the Plum Creek floodplain go wild and enhance those areas with swamp plants and trees and turn the areas over to wildlife.