Where NJDEP or FEMA flood mapping is available, applicants would use existing mapping with the increased safety factor described above. However, if an applicant disagrees with the available flood mapping or where none is provided, "Method 6", as outlined in proposed amendment N.J.A.C. 7:13-3.6(c), provides a framework by which the design flood elevation and floodway limits can be calculated by a licensed professional engineer using the applicant's own hydrologic and hydraulic analysis.

Additionally, proposed amendments to N.J.A.C. 7:13-6.7 provide that structures authorized pursuant to "permit-by-registration," "general-permit by certification," or "general permit" are required to comply with applicable design and construction standards of the Uniform Construction Code under N.J.A.C. 5:23, and the Federal flood reduction standards under 44 CFR Part 60. These requirements mirror the NJDEP's Coastal Zone Management rules at N.J.A.C. 7:7-9.25(f) regarding activities falling under a coastal permit or flood hazard area.

Proposed amendments at N.J.A.C. 7:13-12.6 provide flexibility in compliance for public roadways and railroads used by motor vehicles or trains that are intended for public use and developed on behalf of a public transportation entity (a governmental entity or statutorily authorized public-private partnership program). The NJDEP believes this flexibility is warranted because public roadways constructed by public entities are subject to unique placement constraints that can impact the ability of such a project to comply with stormwater requirements.

Notably, the Department states in the proposal that such unique circumstances are not present in roadways constructed as part of a private development project. Thus, roadways constructed as part of a private development project by a private entity will be subject to the new elevation requirements. This will impact the location and design of access points and private roads in new developments and developments proposed for expansion.

Just as calculated flood hazard areas in fluvial locations will expand due to increased rainfall projections, Stormwater Best Management Practices ("BMPs") required under the Stormwater Management rules for major developments will be subject to design requirements to account for greater volumes of runoff and anticipated increases in runoff.Under the proposed new rules, BMPs for major developments must be designed to manage runoff based on the Cornell precipitation data for current two-, 10-, and 100-year storms as well as for storm events occurring from 2050 through 2099. More specifically, new rule N.J.A.C. 7:8-5.7(c)1 requires usage of National Oceanographic and Atmospheric Administration, National Weather Service's Atlas 14 ("NOAA Atlas 14"). An internet link is provided in the rule to locate the data. New rule N.J.A.C. 7:8-5.7(c)2 requires the modification of NOAA Atlas 14 data for precipitation depth levels of current two-, 10-, and 100-year storms to reflect the new data using county by county adjustment factors. Likewise, new rule N.J.A.C. 7:8-5.7(d) would require usage ofNOAA Atlas 14 data, but projected for storm events in the 2050-2099 timeframe.

Accordingly, use of existing methodologies for computation of hydrographs (used to show water level rates over time) as provided under the current rules would be discontinued as the NJDEP believes these methods are based on an "oversimplification" of complex hydrological processes.

Additionally, there is a certain degree of flexibility provided for major developments associated with public roadways and railroad projects conducted by public transportation entities. Under new rule at N.J.A.C. 7:8-1.6(f), projects that have determined a preferred alternative or reached an equivalent planning and design milestone before the effective date of the rule proposal will not be required to utilize the proposed precipitation change factors for purposes of demonstrating compliance with the Stormwater Management rules. Where, however, a public transportation entity selects a new preferred alternative (or equivalent) for a project after the effective date of the rule proposal, the entity must comply with the stormwater standards effective at the time the project's applicable permit is found complete for review.

Finally, note that the NJDEP stormwater amendments do not amend or supersede the amendments to the Pinelands Comprehensive Management Plan Stormwater Management Rules that took effect for compliance purposes in January 2023.

Flood Hazard Area Rule Grandfather Provisions

Pursuant to proposed new N.J.A.C. 7:13-2.1(c)1, applications for development in currently regulated areas deemed "complete for review" prior to the effective date of the new rules are exempt from the new rules.

Pursuant to proposed new N.J.A.C. 7:13-2.1(c)4, activities in areas currently outside of NJDEP jurisdiction that will be regulated under the new rules are exempted from application of the new rules but only if:

(1) The activity falls completely outside of the current Flood Hazard Areas as of the rule's effective date;

(2) Construction has actually commenced to the point that the activity could not practically be modified and the activity has received all necessary federal, state, and local approvals such that construction could have lawfully commenced prior to the effective date of the rule proposal.

Stormwater Rule Grandfather Provisions

Under proposed amendments to N.J.A.C. 7:8-1.6(2),(3) and (4)i and ii, in order to have the current stormwater rules apply, the permit applicant must have submitted a technically complete application to the NJDEP prior to the effective date of the new rules.