Water Quality In The Ipswich River, Essex County, Massachusetts

Abstract

Modern watersheds face increasing strain due to anthropogenic impact like eutrophication degrading biotic processes and water quality. Present conditions may be creating a eutrophic zone between dams along a segment of the Ipswich River. This study consists of evaluation of hydrographs and in-situ hydrochemical measurements. Four data collection sites were established along the Ipswich River in Essex County, Massachusetts, upstream to downstream: South Middleton at Boston Street Bridge, and Ipswich at Willowdale Mills Dam, Ipswich Mills Dam, and Choate Bridge. Bivariate USGS hydrographs of the Boston Street Bridge sub-watershed and the Choate Bridge watershed show no discrepancies in volume. The Boston Street Bridge sub-watershed displays a steeper recharge curve than Choate Bridge’s gentler recharge curve. For all locations pH and specific conductance rates were within expected ranges for healthy river water. However, dissolved oxygen saturation was lower than the desired 80% at both dam sites. Hydrographs show a steeper curve for Boston Street Bridge, likely due to an increased percentage of urbanized surface area. This ground is impenetrable; runoff flows directly to lower elevations sans soil percolation. A lower percentage of urbanized surface area is recorded for the Choate Bridge watershed; water percolates into lowlands more slowly. Dissolved oxygen levels at the dam sites are low, although this is likely not due to eutrophy. Presently this study doesn’t support eutrophic zones within the Ipswich River; it points to likely zones of low dissolved due to restriction of water and sediment flow. On a municipal scale this research presents important information regarding deterioration of surface water quality due to dams.