I think this chart of Benbrook's levels likely line up with the points made about acquiring water over winter months via the two east Texas reservoirs, playing it out on a gravity feed in the other months. That, and general rain conditions and cooler weather . . . meaning less evaporation would affect the chart history.
If another thread is correct, Lake Palestine will soon be added to the reservoirs that will provide potential water to D/FW.
Over the course of a year, lakes in our region generally lose about 50" or so to evaporation. So, if we get 30" of rain, lose 50" to evaporation, the rest comes from expansive watersheds, other lakes upstream . . . and springs in some cases.
It makes me wonder if the Walsh Ranch project west of Fort Worth, supposedly the largest of its kind in American history, is going to pull water from Benbrook . . . or does it have other water resources in mind?
A chart below. Brad