Aaron Porter and John Jastram
U.S. Geological Survey, Virginia and West Virginia Water Science Center
The USGS Virginia and West Virginia Water Science Center (VA-WV WSC) has developed an urban water-quality monitoring program that includes long-term networks in Fairfax County, Hampton Roads, Roanoke, Salem, Reston, and Ashland, each uniquely designed to meet specific cooperator needs. An overview and key findings from two of those networks, Fairfax County and Hampton Roads, will be included in this presentation.
In 2007, the USGS VA-WV WSC partnered with Fairfax County (VA) to develop and maintain a water-quality monitoring network. In recent decades, Fairfax County has made substantial investments (>$100 million) into the implementation of best management practices (BMPs) aimed at restoring and protecting the county’s watersheds. Measurements of streamflow, water-chemistry, and benthic-macroinvertebrate communities are collected from the 20-station monitoring network to determine the effectiveness of management practices designed to reduce the delivery of nitrogen, phosphorus, and sediment to Fairfax County streams. Key highlights from data collected over the first ten years of the study include patterns and trends in streamflow, specific conductance, nitrogen, and phosphorus, as well as trends in benthic-macroinvertebrate community composition and richness metrics. The results included in this presentation have been synthesized in a USGS scientific investigations report (https://doi.org/ 10.3133/ sir20205061). Additionally, this presentation will include an overview of, and some initial findings from, a companion report (currently in progress) focused on linking these patterns and trends to BMP implementations, changes in land-use/land-cover, stormwater infrastructure, and other important drivers of stream condition.
Meanwhile, in 2015 the USGS VA-WV WSC partnered with the Hampton Roads Planning District Commission (HRPDC), the Hampton Roads Sanitation District (HRSD), and 6 Phase I MS4 localities (Chesapeake, Hampton, Newport News, Norfolk, Portsmouth, and Virginia Beach) to develop and maintain a 12-station long-term regional stormwater monitoring network. This program was initiated because detailed information regarding urban stormwater suspended solids and nutrient loading rates within the Coastal Plain were lacking and a basic understanding of how these loads vary by land-use had yet to be developed. The lack of locally relevant land-use specific loading rates for urban areas in the Virginia Coastal Plain represents a potential limitation for the calibration of the Chesapeake Bay Watershed Model in these areas. The development of locally accurate loading rates and general characterization of water-quality dynamics in the Coastal Plain, specifically the urbanized Hampton Roads region, is essential to informed decision making regarding stormwater management, implementation of BMPs, and compliance with assigned nutrient and suspended solids reduction targets for the Chesapeake Bay Total Maximum Daily Load. This presentation will present an overview of the objectives, approach, and key findings from the first 5-years of monitoring (2016-2020), and comparisons of sediment, nitrogen, and phosphorus loading rates between Hampton Roads (urban Coastal Plain), Fairfax County (urban-Piedmont), Roanoke (urban-Valley and Ridge), and Chesapeake Bay Non-tidal Network stations.