Refining previous estimates of groundwater outflows from the Medina/Diversion Lake system, San Antonio area, Texas

Fact Sheet 2017-3008
Prepared in cooperation with the San Antonio Water System
By: , and 

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Introduction

In 2016, the U.S. Geological Survey (USGS), in cooperation with the San Antonio Water System, began a study to refine previously derived estimates of groundwater outflows from Medina and Diversion Lakes in south-central Texas near San Antonio. When full, Medina and Diversion Lakes (hereinafter referred to as the Medina/Diversion Lake system) (fig. 1) impound approximately 255,000 acre-feet and 2,555 acre-feet of water, respectively.

Most recharge to the Edwards aquifer occurs as seepage from streams as they cross the outcrop (recharge zone) of the aquifer (Slattery and Miller, 2017). Groundwater outflows from the Medina/Diversion Lake system have also long been recognized as a potentially important additional source of recharge. Puente (1978) published methods for estimating monthly and annual estimates of the potential recharge to the Edwards aquifer from the Medina/Diversion Lake system. During October 1995–September 1996, the USGS conducted a study to better define short-term rates of recharge and to reduce the error and uncertainty associated with estimates of monthly recharge from the Medina/Diversion Lake system (Lambert and others, 2000). As a followup to that study, Slattery and Miller (2017) published estimates of groundwater outflows from detailed water budgets for the Medina/Diversion Lake system during 1955–1964, 1995–1996, and 2001–2002. The water budgets were compiled for selected periods during which time the water-budget components were inferred to be relatively stable and the influence of precipitation, stormwater runoff, and changes in storage were presumably minimal. Linear regression analysis techniques were used by Slattery and Miller (2017) to assess the relation between the stage in Medina Lake and groundwater outflows from the Medina/Diversion Lake system.

Suggested Citation

Slattery, R.N., Asquith, W.H., and Gordon, J.D., 2017, Refining previous estimates of groundwater outflows from the Medina/Diversion Lake system, San Antonio area, Texas: U.S. Geological Survey Fact Sheet 2017–3008, 2 p., https://doi.org/10.3133/fs20173008.

ISSN: 2327-6932 (online)

Study Area

Table of Contents

  • Introduction
  • Statistical Reanalysis
  • References Cited
Publication type Report
Publication Subtype USGS Numbered Series
Title Refining previous estimates of groundwater outflows from the Medina/Diversion Lake system, San Antonio area, Texas
Series title Fact Sheet
Series number 2017-3008
DOI 10.3133/fs20173008
Year Published 2017
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Texas Water Science Center
Description Report: 2 p.; Data Release
Country United States
State Texas
Other Geospatial Medina River Basin
Online Only (Y/N) Y
Additional Online Files (Y/N) Y
Google Analytic Metrics Metrics page
Additional publication details