Water Level Monitoring

Groundwater is measured by measugin the static water level in the well. By measuring the depth from the top of the well (Top of Casing) to the standing water level, we know the elevation, or conversely, the depth to water.

The key to underastandsing groundwater fklow is to know the changes within the well over time and the relative water level in nearby wells. As water flows from high to low elevation, we can measure the relative difference in a sreies of wells and infer the direction of groundwater flow.

While groundwater flow is generally horizontal, there are smaller components of vertical flow. When pairs of nearby wells are monitorined for water level, we can use the difference in water level of the two wells and calculate the potential for vertical flow, upward or downward.

Water Level Groundwater Monitoring Well (arcgis.com)

The USGS monitors 4 wells in or nearby Loudoun County

49Y 1 SOW 022 - U.S. Geological Survey - National Ground Water Monitoring Network (usgs.gov)

49Y 1 Sow 022 - USGS Water Data for the Nation

50W 4C - U.S. Geological Survey - National Ground Water Monitoring Network (usgs.gov)

50W 4C - USGS Water Data for the Nation

49V 1 - U.S. Geological Survey - National Ground Water Monitoring Network (usgs.gov)

49V 1 - USGS Water Data for the Nation

48X 20 - U.S. Geological Survey - National Ground Water Monitoring Network (usgs.gov)

48X 20 - USGS Water Data for the Nation

Note the 5 ft upward shift in the Leesburg well was caused by nearby development resultinghg in changes to groundwater recharge

All USGS data are available from the USGS Dashboard.