Research about Upper Delaware River

USGS2015

An integrated Riverine Environmental Flow Decision Support System (REFDSS) to evaluate the ecological effects of alternative flow scenarios on river ecosystems

In regulated rivers, managers must evaluate competing flow release scenarios that attempt to balance both human and natural needs. Meeting these natural flow needs is complex due to the myriad of interacting physical and hydrological factors that affect ecosystems. Tools that synthesize the voluminous scientific data and models on these factors will facilitate management of these systems. Here, we present the Riverine Environmental Flow Decision Support System (REFDSS), a tool that enables evaluation of competing flow scenarios and other variables on instream habitat. We developed a REFDSS for the Upper Delaware River, USA, a system that is regulated by three headwater reservoirs. This version of the REFDSS has the ability to integrate any set of spatially explicit data and synthesizes modeled discharge for three competing management scenarios, flow-specific 2-D hydrodynamic modeled estimates of local hydrologic conditions (e.g., depth, velocity, shear stress, etc.) at a fine pixel-scale (1 m 2 ), and habitat suitability criteria (HSC) for a variety of taxa. It contains all individual model outputs, computationally integrates these data, and outputs the amount of potentially available habitat for a suite of species of interest under each flow release scenario. Users have the flexibility to change the time period of interest and vary the HSC. The REFDSS was developed to enable side-by-side evaluation of different flow management scenarios and their effects on potential habitat availability, allowing managers to make informed decisions on the best flow scenarios. An exercise comparing two alternative flow scenarios to a baseline scenario for several key species is presented. The Upper Delaware REFDSS was robust to minor changes in HSC (± 10 %). The general REFDSS platform was developed as a user-friendly Windows desktop application that was designed to include other potential parameters of interest (e.g., temperature) and for transferability to other riverine systems.

New Jersey, Pennsylvania↗

USGS2002

Quality of water in tributaries to the upper Delaware River, New Jersey, water years 1985-2001

Measurements of nine chemical constituents and properties indicate that median concentrations of nitrate plus nitrite and total phosphorus and levels of fecal coliform bacteria were lower, and median concentrations of dissolved oxygen were higher, in samples from streams in the Upper Delaware River watershed than in samples from randomly selected streams across New Jersey. Concentrations of nutrients and dissolved and suspended solids, levels of fecal coliform bacteria, and water temperatures were lowest, and concentrations of dissolved oxygen were highest at sites on Dunnfield Creek, Flat Brook, and Vancampens Brook. Concentrations of nutrients and dissolved and suspended solids, fecal coliform bacteria levels, pH, and water temperatures generally were highest at sites on the Musconetcong River, Pohatcong Creek, the Pequest River, and the Paulins Kill. Fecal coliform bacteria, total phosphorus concentration, and water temperature are the water-quality measures that most frequently failed to meet water-quality reference levels. Concentrations of most chemical constituents studied and levels of fecal coliform bacteria were lowest, and concentrations of dissolved oxygen were highest, in streams whose watersheds contain the most forested or most undeveloped land. No significant trend over time was found for most of the constituents and properties at most of the 10 sites for which a trend test was conducted; however, concentrations of total phosphorus and un-ionized ammonia decreased at 5 or more of these sites. Water temperature and pH decreased, but concentrations of nitrate plus nitrite, dissolved oxygen, and dissolved-solids increased, at fewer than half of these sites.

New Jersey↗