Historic HOLC Redlining in Indianapolis and the Legacy of Environmental Impacts

Abstract

Redline mapping was adopted by the Home Owner’s Loan Corporation (HOLC) in the 1930s to help assess its lending risk based on observable characteristics in urban neighborhoods across the United States, but the practice has been criticized for evident racial discrimination in addition to financial risk assessment. Researchers have demonstrated that modern urban tree canopy cover is lower in the historically redlined zones of four US cities. This article focuses on Indianapolis, Indiana, where a HOLC map was developed in 1937. Analysis using a geographic information system (GIS) was conducted in order to detect evidence of ecological legacies of redlining. Using this method, evidence of relatively high-intensity development, low greenspace and forest cover, and disproportionately high incidences of brownfield sites, Superfund sites, industrial waste sites, and Interstate highways were detected in historically redlined zones in Indianapolis. While opportunities for further and more detailed research are considered, the method employed here should be developed such that it is replicable for other cities with redlining histories in Indiana and other surrounding states with comparable spatial datasets. This example protocol can be adopted and refined by various stakeholders to establish where the need may exist for programmatic solutions and to better inform policy recommendations.