Today Union College will host its fifth annual symposium on the Mohawk Watershed, the biggest one yet, with scientists, students and government officials in attendance. On the cover of the program will be a photo of the Lock 7 dam in Vischer Ferry, a feature of the river that deserves serious discussion and, more importantly, action. That's because its main distinguishing features -- its height, width and lack of moving parts -- appear to contribute to flooding in Schenectady's Stockade and vicinity.
The dam was built in 1913, just before the Mohawk River started being used for the Barge Canal, and the floods that year and the next were the worst in the city's history.
The problem, according to Union College Geology Professor John Garver and other experts who have analyzed the data, is the dam's height (27 feet from the base, making it one of the largest on the canal system), without any means of letting the water pass through beneath the crest. Add to that the dam's great width (1,900 feet), which slows the water's movement. Then add in ice jams in winter, spring thaws and heavy rains, and you have a recipe for flooding.
Contrast this with the dams at locks upstream, which have movable gates that make it possible to raise or lower water levels in the river. The failure to move them during Hurricane Irene made flooding much worse, and resulted in damage to the gates, locks and surrounding areas. Moving them in advance of Hurricane Sandy helped avoid serious flooding during that storm.
Contrast also the attention those upstream locks have received with the lack of attention given Lock 7 . The state Canal Corp. quickly fixed the locks after Irene, and the Federal Emergency Management Agency recently announced that it will provide $32 million to renovate and improve the movable gates. But when it comes to the dam at Lock 7 , the Canal Corp. says it is the New York Power Authority's responsibility, and FEMA determined that it was outside the scope of its flood mitigation work at the canal locks .
The canal itself was a marvelous feat of engineering when it was built in the early 1800s (with Union College providing many of the engineers) and rebuilt in the early 1900s, with the notable exception of Lock 7 .
There's little doubt that the technology exists to fix the problem, but first it has to be recognized by the various state and federal agencies with jurisdiction. May this symposium -- with the recent floods and the prospect of more with climate change -- be the occasion for that recognition, followed shortly by a plan for action.