Have heard chatter at the fly shop (Orvis Arlington) that guides in the region, Potomac especially, are reporting big drops in the population - thought right now is that the high water last year did some damage, but that's not definitive.
I have not fished the Upper potomac in years; only smallmouth hits for me have been brief wading trips on the Shenandoah and Rapidan. Shenandoah seemed OK, Rapidan was slow. Virtually no topwater bite there.