Green infrastructure isn’t rocket science, but proper design, construction, and maintenance – all essential to long-term success – require a different approach.
View new development and retrofit demonstration project examples.
A number of innovative green infrastructure installations can be found in new development and redevelopment in New Jersey. Here are some examples.
Sustainable Jersey awards points for a pilot green infrastructure project and, separately, for implementing green infrastructure projects that satisfy the short-term and, later, long-term goals identified in the companion planning action.
The American Society of Landscape Architects features 40 case studies illustrating the transformative effects of sustainable landscape design and the use of green infrastructure practices across the country.
Green infrastructure best management practices (GI BMPs) are exceptionally adaptable and can be used in a variety of environmental and land development settings, whether urban, suburban or rural. They also work to control, treat and manage runoff generated from new development and can be integrated easily into existing conventional stormwater collection systems to take pressure off of undersized and aging gray infrastructure, and improve management of stormwater generated from existing development.
Many GI BMPs are designed to work with relatively small catchment areas (drainage areas) to manage the water quality event (1.25 inches of rainfall in two hours) completely, as well as the first flush of larger storms. This is why utilizing GI BMPs in a decentralized stormwater management setting is desirable. This means utilizing a number of small GI BMPs to collect and manage runoff as close to the point of generation as possible. Routing too much runoff through certain types of GI BMPs can compromise the performance of the system and result in scour and erosion impacts to the BMP.
This does not mean that GI BMPs can’t be used for large developments. It only means that they need to be sized and sited properly in order to be effective. The more commonly utilized GI BMPs are highly scalable, meaning that they can be utilized to control, treat and manage runoff generated from both small and large catchment areas. This applies to bioretention basins, infiltration basins, constructed wetlands, and bioswales.
The New Jersey Department of Environmental Protection’s Stormwater Best Management Practices Manual provides detailed guidance on the design and construction of green infrastructure BMPs. Design and construction guidance is also available through Rutgers Cooperative Extension Service. In fact, there are numerous excellent resources detailing how to design, construct, and maintain GI BMPs.
This bears repeating: As is the case with conventional gray infrastructure, it is possible to design, size and construct GI BMPs for a wide variety of applications: big or small catchment areas, new development or redevelopment. In every application, it is imperative that correct site data be collected in advance of implementing a particular GI BMP. This includes but is not limited to:
In every case, all of a site’s characteristics must be accounted for and sound hydrologic and hydraulic data must be developed before selecting a specific GI BMP.
The following should be considered a general guideline to the selection and application of GI BMPs.
Redevelopment or Retrofit
Need To Reduce Nutrients
High Contaminant Area (e.g., gasoline filling station)
Need To Maximize Recharge
Green infrastructure features should become integral to your capital project designs (roads, parks, schools, libraries), and should be reflected in contract specifications and the capital budget. GI doesn’t always cost more, but sources of grants and low-interest loans abound.Find Grants & Loans
Resources & Strategies:Grant Writing Module
Stormwater utilities may become a viable option for New Jersey communities to fund public green infrastructure. Similar to other utilities like energy and water, a stormwater utility provides stormwater management services to its customers for a fee, which are collected to maintain and improve public stormwater systems including green infrastructure. Thirty-nine states have one or more stormwater utilities. New Jersey does not have any. As of September 2018, state legislation to authorize local or regional stormwater utility authorities is pending. To learn more about the current state of stormwater utilities in New Jersey, read the opinion article by Daniel Van Abs, Ph.D., associate professor of practice for water, society, and environment at the Rutgers School of Environment and Biological Sciences: Few Municipalities in NJ Will Create Stormwater Utilities, But Some Should.
The New Jersey Stormwater Best Management Practices Manual (BMP Manual) is developed to provide guidance to address the standards in the state’s Stormwater Management Rules, N.J.A.C. 7:8.
The BMP Manual provides examples of ways to meet the standards contained in the rule and includes structural stormwater management measures such as green infrastructure practice. The methods referenced in the BMP Manual are one way of achieving the standards. An applicant is welcome to demonstrate that other proposed management practices will also achieve the standards established in the rules. The BMP Manual is developed by the New Jersey Department of Environmental Protection, in coordination with the New Jersey Department of Agriculture, the New Jersey Department of Community Affairs, the New Jersey Department of Transportation, municipal engineers, county engineers, consulting firms, contractors, and environmental organizations.
This document provides guidance to combined sewer overflow (CSO) permittees within the State of New Jersey – that is, the 21 cities that have combined stormwater and wastewater systems – to evaluate green infrastructure as part of their required Long Term Control Plans (LTCPs).
In 2015, the NJDEP issued New Jersey Pollutant Discharge Elimination System (NJPDES) CSO permits to 25 permittees that require, among other things, the development of an LTCP to address periodic sewer overflows. As part of the LTCP, the permittee must evaluate alternatives that will reduce or eliminate the CSO discharges, and develop a plan and implementation schedule. Green infrastructure is one of the seven specific CSO control alternatives that must be evaluated for the purposes of the LTCP.
Chapter 3 (titled Green Infrastructure Implementation and Performance Monitoring) discusses the importance of performance monitoring with respect to green infrastructure implementation. While not specifically required by the CSO permit, performance monitoring is integral to assessing whether or not green infrastructure practices are performing as designed and understanding how information gained can be applied on a larger scale. The chapter outlines the development of performance criteria, performance monitoring at the site scale, monitoring and adjustments to hydraulic models, pilot projects, and adaptive management. Finally, the chapter describes community engagement and education for performance monitoring and provides case studies.
The manual, created by the Rutgers Cooperative Extension (RCE) Water Resources Program, provides a wealth of information for planning and design professionals, municipal engineers and officials, community groups, and inspired residents who are interested in installing green infrastructure practices to reduce the negative effects of stormwater runoff.
This manual provides users with information on the function and benefits of green infrastructure practices and technical design standards and describes the design process for a green infrastructure practice, guiding the user through the process from site identification to implementation. Using the details in this manual, stakeholders as well as design professionals that are planning to implement green infrastructure practices into existing development will understand the process from start to finish.
The Urban Street Stormwater Guide provides cities with national best practices for sustainable stormwater management in the public right-of-way, including core principles about the purpose of streets, strategies for building inter-departmental partnerships around sustainable infrastructure, technical design details for siting and building bioretention facilities, and a visual language for communicating the benefits of such projects.
There are a number of quantitative tools that engineers and other design professionals can use to document the pollutant load reduction benefits of green infrastructure BMPs. The choice of which tool to use is largely a function of a project’s goals.
There are a variety of hydrologic/hydraulic computer programs commonly used by engineers, environmental scientists and hydrologists to design and size green infrastructure BMPs correctly. Most of these programs are based on modeling methodologies developed by the NRCS and USDA; specifically, Technical Release 20 (TR-20, 1965) and Technical Release 55 (TR-55, 1975). Public-domain software such as the NRCS WinTR-20 or NRCS WinTR-55 provides basic modeling functionality and can be downloaded for free. Commercially available software including HydroCAD from HydroCAD Software Solutions or Pondpack from Bentley Systems include NRCS unit hydrograph methodology along with robust design and analysis features. When necessary or desirable, there are also more sophisticated approaches readily available, including:
Each of these techniques can be used to quantify the pollutant reduction, expressed either as a load (lbs/yr) or concentration (mg/L) expected as a result of the implementation of one or multiple green infrastructure BMPs used independently, in combination or in series at a specific site or over an entire watershed. Of the six identified techniques, MapShed and SWMM are the most robust. These modeling techniques enable one to compute a pre-development load and a post-development load with and without BMPs. They are also capable of computing pathogen (fecal coliform) levels and include parameters that account for loading from waterfowl, farm animals, domestic pets, and eroding stream banks, which often are a major contributor to suspended solids and nutrient levels in urban and suburban settings.
On 12/3/18, NJDEP announced it is proposing significant changes to the state’s stormwater management rules (NJAC 7:8), which will replace the current requirement that major developments incorporate non-structural stormwater management strategies to the “maximum extent practicable” to meet stormwater management standards for water quality, recharge and volume control, with a requirement that green infrastructure must be utilized to meet these standards.