gauge height How Deep Are Pittsburgh’s Three Rivers? Fort Pitt Bridge’s Secret Room Holds The Answer By Kathleen J. Davis • Jun 7, 2018 Kathleen J. Davis / 90.5 WESA Listen Listening... / 4:47 For 90.5 WESA's Good Question! series, Kathleen Davis explores how water is measured in Pittsburgh's three rivers. Pittsburgh is known for its rivers. But many residents, like 90.5 WESA listener Judith Hoover, aren't sure where the bottom of each of the three lie.