NH WRRC Lakes Lay Monitoring Project

Title: Water Quality Change - Effects of Development on Nutrient Loading in Selected Watersheds
Principal Investigators: Jeffrey A. Schloss

The waters of New Hampshire represent a valuable water resource contributing to the state's economic base through recreation, tourism, and real estate revenues. Some lakes and rivers serve as current or potential water supplies. For most residents (as indicated by boating and fishing registrations and shoreline re-development) our waters help to insure a high quality of life. As documented in the 2000 Census, New Hampshire currently leads all of the New England states in the rate of new development and redevelopment. The long-term consequences of the resulting pressure and demands on the state’s precious water resources remain unknown. Of particular concern is the response of our waters to increasing non-point source pollutant loadings due to watershed development and land use activities.

Of all the in-depth watershed nutrient budget measurements and modeling efforts that have been attempted in NH none have primarily focused on change detection due to development as they were either base-line studies on relatively pristine lakes or focused on specific problems such as internal nutrient loading from past sewage outfalls, or septic systems in the water table of a seepage lake. In addition nitrogen species were only monitored for less than a handful of studies and the measurement technologies at the time were not sensitive enough to provide much usable data. The opportunity to add nitrogen monitoring and support GIS land change analysis to co-occurring externally funded phosphorus watershed nutrient budget studies on two lakes that had previous budgets done in the past provides a true cost-effective project that directly addresses Statewide concerns.

Alone, these watershed nutrient budgets represent only short-term examinations of non-point source pollution nutrient loadings to the lake. A longer-term monitoring program conducted through differing weather years at both shallow and deep sites is required to best estimate the lake response to the loadings due to development over time.

The proposed investigation would allow for the improvement of predictive models used for watershed planning and management for both inland lake watersheds (where phosphorus is the concern) as well as costal and river watersheds (where nitrogen is a concern). The benefits of this are wide ranging from assisting watershed stewardship education efforts throughout the state and region to providing existing watershed based programs like the EPA Basins Model Initiative, the statewide 303d listing process (under the federal Clean Water Action Program) as well as regional and state initiatives (US EPA Region 1 and NE states) to develop total daily maximum loading criteria (TMDLs) and nutrient criteria for lakes, rivers and streams. In addition we expect the data to also be useful in attempts to use the regionally developed USGS SPARROW model with greater resolution in terms of scale. The project will also complement current efforts underway to predict receiving water response to nutrient loading for source water protection planning. In addition the work will provide additional data to include in our submissions to EPA’s new STORET and for use in our ongoing collaborative web based water quality data distribution project between UNH and the NH Department of Environmental Services. The study is also consistent with ongoing studies undertaken by the UNH WRRC program to document land use change impacts on nutrients in surface water and groundwater.