It's comforting to me that hope for improvement and mature, rational stewardship continues.
As far as the legacy sediments, I have learned over the years that most of the mill and water supply dams of yore did not in and of themselves contribute to the build up of legacy sediments.
The cause for the build up was failure to operate them properly.
Mill dams and most small water supply dams in PA with which I have been familiar were made to be flushed regularly, and maintenance was dropped, knowledge and management skills lost.
For Sal, a good example is the former pumping station dam on the Hammer Creek at the now State Game Lands parking area at the junction of Rt. 322 & Pumping Station Road.
When I was young this was one of the first places I ever fished.
It was a deep clear impoundment, and it was flushed (both the Walnut Creek dam and the Hammer Creek dam) regularly by the Lebanon authority that owned it.
Subsequently, after changes in its use and ownership to the Pa. Game Commission, maintenance (annual flushing by raising the gates) ceased. It filled up with silt, especially after the 1972 flood.
The Game Commission was at fault for failing to maintain it, or to eliminate it.
When it was breached, those tons of silt headed down toward Speedwell and smothered the fish-holding habitat below it.
That is just one, but there are many more examples of failure to maintain the intended function of those dams that created the legacy sediments, as they are now called. These didn't take 175 years to create. Much less.