Credit: Kemble Park, E&LP, Inc
Photograph Credit: Kemble Park, E&LP, Inc

New Jersey’s Stormwater Rules and Requirements

Takeaway:

NJ stormwater rules and guidance are changing in ways that will impact almost every development project. Get the facts here.


The New Jersey Department of Environmental Protection (NJDEP) has adopted a revised set of stormwater regulations under N.J.A.C. 7:8 that will affect land development practices within the state. The revised rules, which take effect on March 2, 2021, require the use of decentralized green infrastructure practices and provide a more objective review process for projects.

Previous regulations required the use of nonstructural stormwater management strategies to “the maximum extent practicable.” The new rules eliminate this subjective language and instead provide a clearly articulated, mathematically-based set of standards for stormwater design compliance. The previous nonstructural strategies have been relocated within the rule to function as planning principles instead of conformance review criteria.

A second, but equally important, change relates to permitted stormwater modeling criteria. As explained in Chapters 5, 9, and 13 of the BMP Manual, infiltration of captured stormwater through best management practices (BMPs) is now permitted in engineering calculations. This change will result in smaller stormwater BMPs, thus maximizing developable area on a site.

This section covers the main takeaways from the new rule while also indicating where further reading may be desirable for both developers and engineering consultants.

In order to assist design professionals in selecting the right BMPs to meet these standards, the new rule separates BMPs into three tables:

Table 5-1 consists of green infrastructure BMPs that can be used to meet water quality, water quantity, and groundwater recharge requirements. Table 5-1 presents options for the use of local, decentralized green infrastructure in order to maximize treatment and groundwater recharge.

Table 5-2 consists of green infrastructure BMPs that can be used to meet water quantity standards. BMPs in this table provide alternatives for meeting water quantity requirements for larger sites. These BMPs cannot be used for water quality or groundwater recharge without a waiver/variance. When a development must meet all three (3) requirements, these systems can be used in conjunction with Table 5-1 BMPs.

Table 5-3 consists of structural systems and green infrastructure that may be used only with a waiver or variance.

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