I understand what your all saying,water levels are controlled and used for locks,canals,irrigation. The hydrologic cycle still has to continue, every little bit of precip is another start+winter snow pack definately needed in the north. "Farther below lake ontario..takes in what lake erie can send her". Great song by Lightfoot. Lake 0 is down as much as erie,sailboats were scraping bottom at 50pt marina. Question is how deep can ya dredge before its past the point of practical? It would just be a waiting game for the big boats and some giant commercial lakers for steady water levels.