Integrating Green Stormwater Infrastructure into the Built Environment
Creators: name: Livengood, Avery
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2015

description: Cities are increasingly looking to green stormwater infrastructure (GSI) to attain Clean
Water Act compliance. GSI practices are seen as a sustainable and vital approach to effectively
mitigate water quality impairment associated with wet weather flows. GSI systems may also
provide a wide range of additional ecosystem services and public and private benefits. While
the U.S. Environmental Protection Agency (EPA) has effectively driven widespread adoption of
stormwater management regulations requiring the control of stormwater runoff on-site, these
regulations typically only apply to new development and redevelopment on large sites. In older
cities and neighborhoods, these regulations do not address a significant portion of developed
land that falls below the regulatory size threshold.
EPA, state governments, and non-profit organizations have developed an abundance of
guidance materials, case studies, and handbooks to help municipalities incentivize the
implementation of GSI practices on such properties. Much of the guidance is focused on
incentives that directly impact local finances, including grants, tax credits, stormwater billing
credits, and rebates. Financial incentives are typically outside the control of local planning
departments. However, stormwater management is closely linked to local land use decisions.
Land use decisions affect both the need for better stormwater management, as well as property
owners’ ability to finance, construct and maintain stormwater infrastructure.
Incentive zoning has been proposed as a relatively low-cost tool that can be
implemented by local planning departments to facilitate GSI adoption (Carter & Fowler, 2008).
While there has been little discussion in the peer-reviewed literature on the effectiveness of this
tool for GSI implementation, a simple survey of its prevalence among communities engaged in
stormwater management might inform whether local governments view incentive zoning as a
useful way to manage stormwater on developed sites. This project identifies examples of zoning
incentives for green stormwater infrastructure from a sample of 15 U.S. cities, through review of
local zoning codes, land development ordinances, and subdivision regulations. The variety of
zoning incentives used for GSI were compared to those utilized for other public amenities, in
order to determine whether general incentive zoning practices can inform strategies for
incentivizing GSI.
This project also constructed a model zoning ordinance to provide municipalities
interested in incorporating incentive zoning approaches into their suite of GSI implementation
tools. Development standards for each type of GSI zoning incentive are identified in the sample
ordinances and provided in the model ordinance as examples. Commentary is provided to
assist municipalities with customizing generic ordinance language to fit local circumstances.
Though much of both zoning and GSI implementation is context-specific, the model ordinance
provides a baseline from which municipalities can build, to better integrate GSI into their local
codes.