US Water Quality Index
Our composite Water Quality Score combines temperature, reservoir levels, and flow rates to rate conditions for swimming, fishing, and recreation.
How We Calculate Water Quality Score (0–100)
Maximum points when water temp is near ideal 71.5°F (22°C) for most recreational activities.
Full points when reservoir is at or near full pool capacity. Low levels reduce score.
Moderate, stable flow (100–5,000 cfs) earns full points. Extreme highs or lows reduce score.
Sacandaga River Near Hope Ny
Seneca River Near Seneca Falls Ny
Chenango River Near Chenango Forks Ny
Saranac River At Plattsburgh Ny
Canaseraga Creek At Shakers Crossing Ny
West Branch Delaware River At Hancock Ny
Allen Creek Near Rochester Ny
Richelieu R (Lake Champlain) At Rouses Point Ny
Oquaga Creek At Mcclure Ny
Willowemoc Creek Nr Livingston Manor Ny
Esopus Creek At Allaben Ny
West Branch Neversink River At Claryville Ny
Neversink River Near Claryville Ny
Hudson River At Stillwater Ny
Pepacton Reservoir Near Lewbeach Ny
Niagara River At Joseph Davis State Park Ny
Mohawk River At Rexford Ny
Susquehanna River At Binghamton Ny
Niagara River At Lewiston Ny
Oswego River Near Phoenix Ny
Understanding the Water Quality Index
The US Water Quality Index is a composite score designed to give anglers, swimmers, boaters, and outdoor enthusiasts a quick, at-a-glance assessment of water body conditions. Unlike traditional water quality indices that focus on chemical pollutants (which require laboratory analysis), our index uses real-time USGS sensor data to reflect physical conditions relevant to recreation.
Temperature Component (40 points)
Water temperature is the most important factor for recreational fishing, swimming, and wildlife activity. The ideal range for most activities — comfortable for swimming, optimal for bass and walleye fishing — is approximately 65–78°F (18–26°C). Our scoring peaks at 71.5°F and decreases proportionally as temperature moves away from this ideal.
Reservoir Level Component (30 points)
Reservoir levels (measured as a percentage of full pool) reflect drought conditions, drought recovery, flood risk, and overall ecosystem health. A reservoir at full pool (100%) scores maximum points. Severely depleted reservoirs — common during drought — score fewer points. This metric is particularly relevant in western states where water storage is critical.
Flow Rate Component (30 points)
River discharge (measured in cubic feet per second, cfs) indicates safe boating, wading, and kayaking conditions. Moderate, stable flow rates between 100–5,000 cfs are typically ideal for most recreation. Extremely high flows indicate flood risk, while extremely low flows suggest drought stress and limited habitat for fish.