Water Levels

Water Levels

Oswego is the first deep water port on the Great Lakes and like all Great Lakes Ports, the water level elevations have seasonal variations due to meteorological conditions, snow melt off, rain, wind and barometric pressure. The International Lake Ontario - St. Lawrence River Board regulates Lake Ontario water levels via flow discharge management at the Moses-Saunders Dam, Massena, NY and Cornwall, Ontario, respectfully. The port retains seaway draft commonly during the navigation season.

The Port of Oswego is calculated by the depth of the channel survey by Army Corps plus the reading of the current water level above low water by the NOAA station at the port. The depth of the channel below "Low Water Datum" (LWD - Chart Datum) at the Port of Oswego maintained by the US Army Corps of Engineers. The base water level reference for these measurements are determined from gauges throughout the Great Lakes by NOAA.

The Port of Oswego has in its harbor the "Master" water level gauge for all of Lake Ontario. It is the zero reference for the lakes chart datum (LWD) and all gauges, US and Canadian on the lake were zeroed to it at the onset of the International Great Lakes Datum (IGLD) presently IGLD (1985). This gauge station at the Oswego Port transmits, near real time, every 6 minutes, the above meteorological data and the water level elevation above or Chart Datum (LWD). All water level readings when reported as "Above" LWD provide the extra amount of water allowing deeper draft vessels into the port.