Pawtuckaway Lake Association

Geosyntec Consultants, Inc. (Geosyntec) was contracted by the New Hampshire Department of Environmental Services (NHDES) to develop a Watershed Based Plan (WBP) for Pawtuckaway Lake (1,180 acres), located in Nottingham, NH. The lake has an 18.5 square mile watershed, including Pawtuckaway Lake State Park and an estimated 309 year-round and seasonal homes located around the lake’s perimeter.

Pawtuckaway Lake has experienced declines in water quality in recent years, as indicated by increasing inlake phosphorus concentrations and increasing occurrences of nuisance blue-green algae blooms. In freshwater lakes, phosphorus is usually the most important nutrient determining the growth of algae and aquatic plants. Because phosphorus is typically relatively less abundant than nitrogen, it is considered the “limiting nutrient” for biological productivity. As such, increases in phosphorus levels tend to be strongly correlated with decreased water clarity, increased algal abundance and other indicators of declining water quality.

The primary purposes of this WBP are: 1. to identify and quantify specific sources of phosphorus contributing to the lake’s water quality impairments; and 2. to develop a management plan to reduce phosphorus loading to the lake to a targeted level that would significantly improve in-lake conditions.

To achieve the goals listed above, this WBP includes the following elements, in conformance with the U.S. Environmental Protection Agency’s guidance for watershed based plans:

a. Identify Pollutant Sources
b. Pollutant Load Reduction Estimates
c. Describe Nonpoint Source Pollution Management Measures
d. Estimate Technical and Financial Assistance
e. Public Information and Education
f. Implementation Schedule
g. Interim Milestones
h. Evaluation Criteria
i. Monitoring