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Green Infrastructure Requirement

The live Sources/ corpus ties the green infrastructure requirement to two related but distinct rule layers: the definition of green infrastructure in N.J.A.C. 7:8-1.2 and the operative design standards in N.J.A.C. 7:8-5.3. The 2026 source set also adds the volumetric reduction pathway at N.J.A.C. 7:8-5.6(d).

Structured citation evidence for this page lives in the sibling claim manifest.

Regulatory Summary

In the current source-backed rule set, green infrastructure is defined as a stormwater management measure that manages stormwater close to its source by:

  • treating runoff through infiltration into subsoil
  • treating runoff through filtration by vegetation or soil
  • storing runoff for reuse

That definition matters because the operative standards in N.J.A.C. 7:8-5.3 are organized around which BMP tables may be used for each stormwater objective.

Source-backed rule snapshot

Rule lane What the live source set says
Definition N.J.A.C. 7:8-1.2 defines green infrastructure; it is not replaced by a new 2026 definition package
Recharge and runoff quality N.J.A.C. 7:8-5.3(b) points to Table 5-1 GI BMPs and approved alternatives that meet the GI definition
Runoff quantity N.J.A.C. 7:8-5.3(c) uses the Table 5-1 / Table 5-2 structure
Exception path N.J.A.C. 7:8-5.3(d) is where Table 5-3 becomes relevant after the variance or waiver path
2026 retention path N.J.A.C. 7:8-5.6(d) adds volumetric reduction as a distinct compliance subsection

How N.J.A.C. 7:8-5.3 works

For groundwater recharge and stormwater runoff quality, N.J.A.C. 7:8-5.3(b) directs the design engineer to use green infrastructure BMPs from Table 5-1 and/or an approved alternative stormwater management measure.

For stormwater runoff quantity, N.J.A.C. 7:8-5.3(c) allows BMPs from Table 5-1 or Table 5-2 and/or an approved alternative stormwater management measure.

BMPs from Table 5-3 are not the default path. Under N.J.A.C. 7:8-5.3(d), Table 5-3 BMPs enter the compliance picture only when a variance under N.J.A.C. 7:8-4.6 or a waiver from strict compliance under N.J.A.C. 7:8-5.2(e) has been granted.

What Changed in 2026

The most important 2026 addition is not a new standalone definition of "Non-GI BMP." The rule text instead adds and clarifies how different BMP tables are used and adds the volumetric reduction standard at N.J.A.C. 7:8-5.6(d).

That distinction matters:

  • "Green infrastructure" is a defined term in N.J.A.C. 7:8-1.2.
  • "Non-GI BMP" is an operational shorthand tied to the table structure in N.J.A.C. 7:8-5.3, not a standalone defined term in 7:8-1.2.
  • volumetric reduction is not a standalone N.J.A.C. 7:8-5.9 section; it is the 2026 subsection at N.J.A.C. 7:8-5.6(d).

Volumetric reduction in 2026

N.J.A.C. 7:8-5.6(d) creates a retention-focused pathway tied to the water quality design storm. In the rule text, that standard is addressed through retention using Table 5-1 and Table 5-2 BMPs, together with the alternative methods and offsite options described in the subsection.

The subsection is more specific than older GI-first shorthand. N.J.A.C. 7:8-5.6(d)1 requires stormwater management measures to achieve retention of the WQDS by incorporating green infrastructure BMPs from Table 5-1 and Table 5-2 unless the applicant demonstrates technical impracticability under N.J.A.C. 7:8-4.6(a)1 or the stormwater source is subject to N.J.A.C. 7:8-5.4(b)3.

BMP Manual Chapter 14 then explains the engineering fallback when onsite retention cannot be met by infiltration. The live source set gives examples such as tested subsoil conductivity below 1 inch per hour, a SHWT that cannot maintain the required separation, and stormwater that is barred from infiltration. In those cases, the volumetric-reduction standard can instead be met by BMPs that attenuate the post-construction WQDS peak flow and extend runoff hydrograph duration to match an undisturbed wooded area on HSG D soil. The examples listed in Chapter 14 include grass swales, underdrained bioretention, underdrained pervious paving, underdrained sand filters, vegetative filter strips, and standard constructed wetlands.

The subsection also allows offsite retention of an equivalent or greater WQDS volume. The live source set keeps that path within the same HUC-14 unless the transportation-entity exception applies, and applications using offsite retention or impervious-surface removal are incomplete without sufficient project information and property-owner permission for the offsite work.

The practical takeaway is that the 2026 rule set adds a volumetric reduction compliance layer, but that layer should not be confused with the base definition of green infrastructure or with the separate table logic in N.J.A.C. 7:8-5.3.

Engineering Interpretation

For authored guidance, the safest summary is:

  1. Determine which of the recharge, quality, quantity, and volumetric reduction standards apply.
  2. Use the BMP tables exactly as the rule assigns them.
  3. Treat Table 5-3 use as exception-based, not default.
  4. Keep the 2026 volumetric reduction analysis separate from the older shorthand descriptions of "GI-first" design.

That framing restores useful detail from the older material without carrying forward two recurring errors:

  • collapsing every BMP classification question into the definition section at 7:8-1.2
  • describing volumetric reduction as if it replaced the table logic in 7:8-5.3

This avoids two common mistakes:

  • treating every 2026 design issue as if it were a new definition change in 7:8-1.2
  • collapsing the recharge, quality, quantity, and volumetric reduction standards into a single undifferentiated GI requirement

BMP Implications

The source-backed table logic has direct implications for page-level engineering guidance:

Standard Default BMP path in the live rule set
Groundwater recharge Table 5-1 GI BMPs and/or approved alternative measures
Stormwater runoff quality Table 5-1 GI BMPs and/or approved alternative measures
Stormwater runoff quantity Table 5-1 or Table 5-2 BMPs and/or approved alternative measures
Exception path after variance or waiver Table 5-1, Table 5-2, or Table 5-3 BMPs and/or approved alternative measures
2026 volumetric reduction Table 5-1 and Table 5-2 BMPs plus the alternatives within N.J.A.C. 7:8-5.6(d)

Cross References