Hampton Roads Regional Water-Quality Monitoring Program

How much nitrogen, phosphorus and suspended solids do the heavily urban areas of Hampton Roads, Virginia, deliver to Chesapeake Bay? The answer matters for policy, funding and the effort to restore clean water to the bay and its tributaries.

To measure it, the U.S. Geological Survey (USGS) and the Hampton Roads Sanitation District (HRSD), with the Hampton Roads Planning District Commission (HRPDC), run a regional water-quality monitoring program.

A water-quality sonde and flow meter measure a storm at an outfall in Newport News, Va. USGS.

Why this region needs its own program

Hampton Roads lies on the Atlantic Coastal Plain — low and flat — and its urban development makes for an unusual ecological and hydrological setting. Recent estimates and regulations for sediment and nutrients reaching the bay have rested mostly on monitoring outside the Coastal Plain, and no one knows whether those results fit urban Hampton Roads.

How urban stormwater affects the bay

• In theory, a buffer: flat land makes meandering streams that flow into tidal estuaries. Left undisturbed, their slow water lacks the energy to carry much sediment, and holds water long enough for organisms to consume nutrients washed from uplands.
• Urbanization changes that: roads, sidewalks, parking lots, rooftops and compacted soil keep rain from soaking in. Water gathers fast and runs off, with the energy to move more particles and less time for nutrients to be removed. Flat ground plus fast runoff also means flooding.
• Storm sewers: an extensive network carries stormwater away efficiently — and carries contaminants straight to receiving waters.
• The damage: suspended solids cut habitat and light for aquatic life; excess nutrients feed algae that, as they decay, use up the oxygen aquatic life needs.

A monitoring station: data logger, telemetry and refrigerated sampler. USGS.

How the monitoring works

• Network: 12 long-term stations, 2 in each of Newport News, Hampton, Portsmouth, Chesapeake, Norfolk and Virginia Beach.
• Small watersheds: each drains 30 to 300 acres, mostly of one land use — single-family residential, high-density residential, or commercial/light industrial.
• Equipment: a data logger, satellite transmitter and refrigerated automatic sampler in a rugged enclosure beside or above the stormwater conveyance.
• Continuous data: flow rate, water temperature, specific conductance and turbidity, uploaded automatically to the USGS online database.
• Storm samples: the sampler collects water during stormflow; HRSD lab staff analyze it for total suspended solids and nutrients.
• Open data: near real time, posted hourly, on the program's website.

During storms in May 2016, total suspended solids (red, mg/L) and turbidity (black, FNU) rise with flow (blue, ft³/s). USGS.

The station network and land use. Land use from the 2006 National Land Cover Database (Fry and others, 2011); base from the U.S. Census Bureau. USGS.

What the data are for

The program will compute monthly and annual loads of nutrients and total suspended solids. The aim is better local stormwater management, through a clearer understanding of how — and how much — nutrients and sediment travel from these urban landscapes to Chesapeake Bay.

Sources

Based on Hampton Roads Regional Water-Quality Monitoring Program, by Aaron J. Porter and John D. Jastram, U.S. Geological Survey Fact Sheet 2016–3095 (DOI; publication page), USGS Virginia and West Virginia Water Science Center. Photographs, graph and map are restored from the fact sheet's PDF. A work of the United States government in the public domain.