Water: Green Infrastructure
Cost-Benefit Resources
Green infrastructure can often provide more benefits at lesser cost than single-purpose gray infrastructure. A growing body of research and experience demonstrates the potential for green infrastructure to improve the triple bottom line at multiple scales. This section provides access to some of the most recent cost-benefit analyses, as well as several tools that developers and communities may consult to inform their own analyses.
This page provides links to non-EPA web sites that provide additional information. You will leave the EPA.gov domain and enter another page with more information. EPA cannot attest to the accuracy of information on that non-EPA page. Providing links to a non-EPA Web site is not an endorsement of the other site or the information it contains by EPA or any of its employees. Also, be aware that the privacy protection provided on the EPA.gov domain (see Privacy and Security Notice) may not be available at the external link. 
Low Impact Design vs. Conventional Development (PDF) (46 pp, 92K, About PDF) – This report compares the construction costs of conventional and low impact development (LID) approaches for nine subdivisions in the United States and Auckland, New Zealand.
Pembroke Woods: Lessons Learned in the Design and Construction of an LID Subdivision (PDF) (9 pp, 285K, About PDF) – This case study of a 43-acre residential subdivision in Frederick County, MD documents the cost savings achieved by adopting a green infrastructure approach. Cost savings were realized by eliminating the need for stormwater management ponds; reducing the extent of clearing, grubbing, and paving; and adding two additional lots.
Changing Cost Perceptions: An Analysis of Conservation Development (PDF) (98 pp, 5MB, About PDF) - This report prepared for the Illinois Conservation Foundation and Chicago Wilderness compares the stormwater management costs of conservation development with those of conventional development. The report defines conservation development as an approach that "addresses stormwater on-site by distributing water across the landscape."
Low Impact Development at the Local Level: Developers’ Experiences and City and County Support (PDF) (22 pp, 233K, About PDF) – This report by ECONorthwest focuses on two aspects of LID adoption at the local level: the experiences that developers have had with LID, and actions that local jurisdictions can take to increase LID use.
Forging the Link, Chapter 3: Economics and LID (PDF) (40 pp, 3.5MB, About PDF) – This report by the University of New Hampshire Stormwater Center includes a series of case studies demonstrating how adopting a green infrastructure approach can lead to more cost-effective site designs and stormwater management systems.
Reducing Stormwater Costs through Low Impact Development (LID) Strategies and Practices (PDF) (37 pp, 769K, About PDF) – This EPA report summarizes 17 case studies of developments that include Low Impact Development practices and compares project costs to typical costs for conventional development.
The Economics of Low Impact Stormwater Management in Practice – Glencourt Place (PDF) (15 pp, 442K, About PDF) – This paper compares the life cycle costs of a green infrastructure approach with those of a conventional approach to a retrofit of a residential subdivision.
The Economics of Low Impact Development: A Literature Review (PDF) (40 pp, 429K, About PDF) – This literature review summarizes the benefits of LID, three methodologies for assessing the economic impact of LID, and the results of more than 50 studies.
NYC Green Infrastructure Plan: A Sustainable Strategy for Clean Waterways (PDF) (16 pp, 2.7MB, About PDF) – As described in this plan released by New York City, modeling results indicate that a combined sewer overflow (CSO) reduction strategy that combines green and gray infrastructure can yield greater reductions in CSO volumes at a lesser cost than an all gray strategy while providing more community benefits.
A Triple Bottom Line Assessment of Traditional and Green Infrastructure Options for Controlling CSO Events in Philadelphia’s Watersheds (PDF) (169 pp, 812K, About PDF) - This report compares the benefits provided by a green infrastructure approach to CSO control to the benefits provided by a traditional tunnel approach. The report monetizes a range of environmental, social, and public health benefits.
Fresh Coast Green Solutions: Weaving Milwaukee's Green & Grey Infrastructure for a Sustainable Future (28 pp, 4.3MB, About PDF) - This report prepared by the Milwaukee Metropolitan Sewerage District explains Milwaukee's goal of achieving zero sewer overflows with combined green and gray systems. The report features a comparison of capital costs for green infrastructure measures, as well as a detailed summary of the multiple environmental, social, and economic benefits associated with different green infrastructure measures.
Cost Benefit Evaluations of Ecoroofs (PDF) (37 pp, 2.1MB, About PDF) - Ecoroofs are expected to be an important part of Portland’s urban strategy as the city grows and density increases in the decades to come. This report attempts to quantify the private and public costs and benefits of green roofs in Portland, Oregon.
Low Impact Development, An Economic Fact Sheet (PDF) (8 pp, 1.2MB, About PDF) - The purpose of this factsheet is to provide basic economic information on Low Impact Development. This simplified overview of a complicated topic is intended to help citizens, developers, and policy-makers have an informed discussion about the costs, benefits, and trade-offs of LID in their community.
The Value of Green Infrastructure: A Guide to Recognizing Its Economic, Environmental, and Social Benefits (PDF) (8 pp, 16.3MB, About PDF) - This guide describes the steps necessary to quantify and value many of the environmental, social, and public health benefits of green infrastructure. The guide includes simple, illustrative examples to assist the reader in performing their own calculations.
Green Values National Stormwater Management Calculator – This screening-level tool developed by the Center for Neighborhood Technology allows site designers to quickly compare the performance, costs, and benefits of green infrastructure practices to conventional stormwater practices.