The phosphorus data shown here represents an estimate of total Vermont loads of phosphorus, based on estimated loads from major Vermont tributaries to Lake Champlain. Total gaged areas for tributaries located primarily in VT are adjusted by the proportion of gaged area relative to total VT watershed area in the Lake Champlain drainage to estimate total VT loads. This number is an approximation, as gaged areas may not be a perfect analogue to un-gaged areas, particularly in the direct Champlain drainage area. Higher amounts of precipitation, particularly heavy rainfall, move more phosphorus from the land to flowing waters and on downstream to the lake. As a result, annual phosphorus loading patterns closely follow annual stream flow patterns. The target load of 418 metric tons total phosphorus represents the maximum amount of phosphorus the lake can receive each year, as specified by the Phosphorus Total Maximum Daily Loads (TMDLs) for Vermont Segments of Lake Champlain, and continue to meet water quality standards. With the passage of the Vermont Clean Water Act (Act 64) in 2015, we now have additional permitting and funding tools to further reduce phosphorus loads to our rivers, streams, and lakes. Decreased loading should be measurable at a local level (individual smaller rivers and streams) as implementation progresses, however it is likely to take many years to show substantial progress in the larger Champlain tributaries and the lake itself. The DEC utilizes additional metrics to evaluate load reductions over time (see our annual RBA report for more information). Loads are calculated and reported for Water Year (year 2020 starts Oct. 1, 2019 and ends Sept. 30, 2020). Water year is the same as Federal Fiscal Year (FFY). NOTE: We have adopted a new approach for calculating total estimated loads that represents our “best available/improved understanding” method and have updated the table for current and past years to represent this improved methodology.

The target load of 418 metric tons total phosphorus represents the maximum amount of phosphorus the lake can receive each year, as specified by the Phosphorus Total Maximum Daily Loads (TMDLs) for Vermont Segments of Lake Champlain, and continue to meet water quality

Loads are calculated and reported for Water Year (year 2020 starts Oct. 1, 2019 and ends Sept. 30, 2020). Water year is the same as Federal Fiscal Year (FFY). NOTE: We have adopted a new approach for calculating total estimated loads that represents our “best available/improved understanding” method and have updated the table for current and past years to represent this improved methodology.