Stormwater Reduction and Water Budget for a Rain Garden on Sandy Soil, Gary, Indiana, 2016–18

Scientific Investigations Report 2022-5101
Prepared in cooperation with the Great Lakes Restoration Initiative
By: , and 



Stormwater reduction measures, or green infrastructure, were implemented in the parking area at Gary City Hall, Gary, Indiana, with the intention of reducing stormwater discharge to the sewers. A study area, including a centrally located rain garden and the surrounding paved surfaces and green space, was instrumented during both a preconstruction and a postconstruction period to (1) develop water budgets to improve understanding of the rain garden hydrology and (2) determine the quantity of stormwater runoff that was diverted and retained by the green infrastructure instead of reaching the combined storm and sanitary sewer. The study was focused on warm-season precipitation and was monitored during spring, summer, and fall of 2016, 2017 and 2018.

Before construction of the rain garden in the parking lot of Gary City Hall in 2017, nearly all precipitation was conveyed away from the parking lot by underground drains, discharged to the sewer, and treated as sanitary waste at the Gary Sanitary District’s treatment plant or discharged directly to local waterways if stormflow exceeded capabilities of the sewage treatment plant. A goal of the Great Lakes Restoration Initiative is the reduction of sewer overflows to local waterways to improve the quality of water entering the Great Lakes. Cities such as Gary benefit financially and environmentally by reducing discharges of stormwater runoff to the sewer system, eliminating the need for treatment. Before implementation of green infrastructure at Gary City Hall, approximately 25 percent of precipitation (approximately 10,200 cubic feet) discharged as stormwater to the sewers through the parking lot drain. After implementation, 2 percent of precipitation discharged to the sewers. For the spring, summer, and fall seasons of 2017 and 2018, 21–24 percent (about 10,700–19,700 cubic feet) of precipitation was captured by the newly installed rain garden. Stormwater discharged to the rain garden infiltrated the sandy soil and was later evaporated from the soil surface, was transpired by plants, or recharged the underlying groundwater aquifer. The percent reduction in stormwater discharged to the storm sewer after the construction of the rain garden was 80.3 percent, equating to approximately 21,400 and 39,300 gallons of stormwater in 2017 and 2018, respectively.

Suggested Citation

Lampe, D.C., Bayless, E.R., and Follette, D.D., 2022, Stormwater reduction and water budget for a rain garden on sandy soil, Gary, Indiana, 2016–18: U.S. Geological Survey Scientific Investigations Report 2022–5101, 39 p.,

ISSN: 2328-0328 (online)

Study Area

Table of Contents

  • Acknowledgments
  • Abstract
  • Introduction
  • Methods of Investigation
  • Stormwater Reduction
  • Water Budget Analysis
  • Limitations
  • Summary and Conclusions
  • References Cited
  • Appendix 1. Monitoring Sites Used for Gary City Hall Green Infrastructure Evaluation
Publication type Report
Publication Subtype USGS Numbered Series
Title Stormwater reduction and water budget for a rain garden on sandy soil, Gary, Indiana, 2016–18
Series title Scientific Investigations Report
Series number 2022-5101
DOI 10.3133/sir20225101
Year Published 2022
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Ohio-Kentucky-Indiana Water Science Center
Description Report: viii, 39 p.; Data Release
Country United States
State Indiana
City Gary
Online Only (Y/N) Y
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page
Additional publication details