I’m not sure what you mean. The reservoirs tend to sit at a watershed’s egress point, runoff is obligated to pass through it. If there’s ample room in the reser

I’m not sure what you mean. The reservoirs tend to sit at a watershed’s egress point, runoff is obligated to pass through it. If there’s ample room in the reservoir, no runoff is lost. I think a correct reading of the article, which is perhaps too oblique on this point, is the loss of water to runoff where it is not in a watershed with a major reservoir, and not able to infiltrate into the aquifer. Add some runoff, such as agricultural runoff, is heavily polluted, complicating the matter even more.