The lake is high, the lake is low. Here’s what you need to know!
Seneca Lake’s water level changes throughout the year in response to rainfall, runoff, evaporation, and regulated outflow. Use this page to check current lake levels, understand how the lake is managed, explore historical data, and prepare for unusually high or low water.
Current Seneca Lake Level
Live lake-level data are shown below, with additional streamflow information from key tributaries and the Seneca River available in the dropdown.
View Watershed Streamflow Data
Water Flow and Level Management
Seneca Lake is part of the network of lakes, canals and waterways that comprise the Oswego River Basin. The Oswego River Basin drains water from an area of 5,122 square miles, towards Lake Ontario.
Water can flow into Seneca Lake faster than it can flow out. The downstream area is relatively flat and the outflow is regulated; therefore the lake takes longer to drain than to fill. All of the water in Seneca Lake leaves near Geneva through the Cayuga-Seneca Canal. The brown arrows on the map below show the direction of watershed flow. The purple arrows show the direction of the canal flow.
Seneca Lake’s outflow is managed by Relevate Power (formerly Gravity Renewables), which operates hydroelectric power plants in Waterloo and Seneca Falls. Their goal is to generate clean energy while complying with federal regulations.
Water from Seneca Lake exits through the Cayuga-Seneca Canal, where flow is measured at a river gauge near the Rt-89 bridge in Seneca Falls. The New York State Canal Corporation also manages a small bypass gate and canal locks to ensure safe navigation downstream toward Lake Ontario.
Seneca Lake Rule Curve
Lake levels are guided by the Seneca Lake Rule Curve, developed in the 1970s, which defines acceptable high and low limits. These targets help balance water levels to prevent flooding or drought, while supporting recreation and protecting natural resources.
Summer Target
446.0 ft
± 0.3 ft (reached by mid-March)
Winter Target
445.0 ft
± 0.3 ft (reached by mid-December)
Each lake has a rules curve to guide its water level management. But there is only voluntary coordination among the lakes to manage both lake level and water discharge from each lake. Since each management unit has different objectives there are occasional conflicts.
Historical Lake Level Archives
Explore Seneca Lake’s historical water levels using the annual graphs below. Click “View Graph” next to any year to view the full graph.
| Year | Lake Level Graph |
|---|---|
| 2025 | View Graph. |
| 2024 | View Graph. |
| 2023 | View Graph. |
| 2022 | View Graph. |
| 2021 | View Graph |
| 2020 | View Graph. |
| 2019 | View Graph. |
| 2018 | View Graph. |
| 2017 | View Graph. |
| 2016 | View Graph. |
| 2015 | View Graph. |
| 2014 | View Graph. |
How You Can Help
Use the resources below to view current Seneca Lake levels, target ranges, and additional gauge information.
Changes in lake level, particularly during heavy rainfall and high-water events, can increase runoff and erosion that carry sediment and nutrients into Seneca Lake. Pure Waters’ Sediment and Nutrient Pollution Reduction (SNPR) Program supports projects throughout the watershed that help reduce these pollutants before they reach the lake.
