USGS Science in Albemarle and North Landing River watersheds

Mark Bennett, USGS April 19, 2018

Land Subsidence 1940-1970 (mm/yr) Published by National Geodetic Survey

Holdahl and Morrison, 1974

Groundwater Drawdown (1939-1974)

Extends beyond state boundaries

Subsidence across

watersheds NC-VA Groundwater

Subcommittee (1975)

HRSD Nansemond Extensometer Construction

• August 15 to December 16, 2016 • Total boreholes drilled: 8 • Total footage drilled: 6,860 ft • Number of observation wells: 5

HRPDC Benchmark Monitoring

23 Class B or greater benchmarks

Calibration points for InSAR analysis at ODU

Land surface motion at fixed points

OPUS solutions to millimeter accuracy

Collaborators: NASA Langley, NGS, and NOAA CO-OPS

5-years of GNSS surveying

U.S. Department of the Interior U.S. Geological Survey

Hampton Roads Regional Water Quality Monitoring Program:

Assessing urban nutrient and sediment yields in the Coastal Plain

Problem

Data describing urban stormwater sediment and nutrient loading rates within the Coastal Plain are lacking

Objectives

1. Collect high quality nutrient and sediment data representative of the Coastal Plain

2. Compute loads that can be compared to those developed for the Chesapeake Bay TMDL

Stormwater Monitoring Approach 12 station network

Newport News Hampton Norfolk Portsmouth Virginia Beach Chesapeake

Primary land-use types High-density residential Single-family residential Commercial & Industrial

Intensive Monitoring Continuous data collection (5 minute)

Flow (level, velocity) Turbidity SC Water temperature

Nutrient and Sediment Sampling Storm event sampling w/ autosamplers 40-60 per site per year

Load Computation Nutrients and sediment Surrogate computations using continuous data

Tidal Monitoring Network

Beggars Bridge

Pungo Ferry

Northwest River

Real-time data

6-min interval upload

TMDLs/Rising GW

Virginia Beach GW Monitoring Network

VA Tech/USGS Collaboration 1. Shallow groundwater tables –

Johnson, Sample, and McCoy (in press- JIDE)

USGS 2013-2017 Sampling

1. 10 QW samples/yr

1. Ecoli – Rapid transport of nutrients and coliphage in rural areas near onsite waste water infrastructure

1. Focus on <40 ft deep wells -

Locally elevated nutrients in urban areas

HRPDC Stormwater Network

Rising Groundwater Levels – Water Quality Limitations and Groundwater Inundation

sUAS multispectral and natural color imaging to document current conditions and map areas of stressed vegetation along coastal wetland/upland boundaries Extended periods of inundation have contributed to vegetation stress and changes in wetland plant communities

Back Bay NWR Coastal Wetland Study