Documentation of a Soil-Water-Balance Model to Estimate Recharge to Blue Ridge, Piedmont, and Mesozoic Basin Fractured-Rock Aquifers, Fauquier County, Virginia, 1996 through 2015

Scientific Investigations Report 2019-5056
Prepared in cooperation with the Fauquier County Department of Community Development
By:  and 



This report documents a Soil-Water-Balance (SWB) model that was developed for an area covering the Blue Ridge, Piedmont, and Mesozoic basin fractured-rock aquifers in Fauquier County, Virginia, for the calendar years 1996–2015. The SWB model includes an area of 1,498 square miles, divided into 1,076-square-foot (100-square-meter) grid cells on which daily groundwater recharge was estimated using existing elevation, meteorological, land-use, and soil property datasets.

Daily groundwater recharge estimates obtained from the model were summarized annually, and annual model output was compared to the results of the hydrograph separation method, PART, on streamflow data from two streamgages in Fauquier County with periods of continuous record overlapping those of the SWB model period (01643700 Goose Creek near Middleburg, Virginia, and 01656000 Cedar Run near Catlett, Virginia). Spatially distributed groundwater recharge results from the SWB model represent annual conditions and the 20-year average values for the years 1996–2015, including estimated recharge during a previously defined drought in 2001. The 20-year average recharge in Fauquier County from the SWB model ranged from 8.1 inches per year (in/yr) in Blue Ridge aquifers to 5.3 in/yr in Mesozoic basin aquifers. Although mean annual precipitation volumes vary slightly across the County, the contrast in recharge among the Blue Ridge and western Piedmont aquifers with that of the Mesozoic basin aquifers is largely a result of differences in soil infiltration capacity. Precipitation totals 20 percent below mean annual precipitation from 1996–2015 produced drought recharge rates that were less than 50 percent of mean annual recharge.

The SWB model and model output, including spatially distributed annual estimates of groundwater recharge, evapotranspiration, and gross precipitation for the 1996 through 2015 model period, are publicly available as a U.S. Geological Survey data release.

Suggested Citation

McCoy, K.J., and Ladd, D.E., 2019, Documentation of a Soil-Water-Balance model to estimate recharge to Blue Ridge, Piedmont, and Mesozoic Basin fractured-rock aquifers, Fauquier County, Virginia, 1996 through 2015: U.S. Geological Survey Scientific Investigations Report 2019–5056, 22 p.,

ISSN: 2328-0328 (online)

Study Area

Table of Contents

  • Abstract
  • Introduction
  • Methods
  • Recharge Results
  • Summary
  • References Cited
Publication type Report
Publication Subtype USGS Numbered Series
Title Documentation of a Soil-Water-Balance Model to estimate recharge to Blue Ridge, Piedmont, and Mesozoic Basin fractured-rock aquifers, Fauquier County, Virginia, 1996 through 2015
Series title Scientific Investigations Report
Series number 2019-5056
DOI 10.3133/sir20195056
Year Published 2019
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Tennessee Water Science Center, Virginia Water Science Center, VA/WV Water Science Center
Description Report: v, 22 p.; Data Release
Country United States
State Virginia
County Fauquier County
Online Only (Y/N) Y
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page
Additional publication details