Water Quality Dynamics in Pockwock Lake Tributaries

Abstract

In forested watersheds, carbon, phosphorus, nitrogen, and suspended sediment, are affected by hydrologic regime, landscape characteristics, and forest management practices. These constituents can impact the quality and treatability of source water, which can increase treatment costs and the formation of harmful disinfectant by-products. A 12-month monitoring program was implemented in the Pockwock Lake Watershed prior to forest harvesting in five catchments to: (i) investigate the influence of different watershed attributes (e.g. size, topography, land cover) on hydrologic response and water quality, and (ii) characterize seasonal and event scale water quality variation. Clear seasonal water quality trends were identified for dissolved organic carbon and phosphorus. Catchment area and wetland coverage had the greatest correlation with hydrologic regime and water quality. Intensive sampling during rainfall events indicated that direct runoff typically only occurs during extreme events, and that Pockwock Lake catchments are transport-limited with respect to dissolved organic carbon loading.