I am not a hydro engineer..............................but to me.........if what the below is saying...........that the Tidal basin is flushing out Washington Channel............then...........why does Washington Channel flow South?  I.e..........towards the Anacostia..........................




The reservoir would release 250 million gallons of water captured at high tide twice a day, flushing the channel free of sediments and impurities. The Reservoir and the Outlet Bridge, the structure that released the water to the channel, were completed in 1889; an Inlet Bridge to control the stored water was added in 1909.