Permeable resin-bound surfacing can help a Princeton project manage stormwater, but under the municipality's land use code it will not shrink your impervious cover. Princeton's stormwater ordinance lists porous asphalt and porous concrete among impervious surfaces, so a permeable pavement still counts toward the 400-square-foot and 5,000-square-foot thresholds. Where it earns its place is as a storage and treatment practice, built over an open-graded stone reservoir with infiltration or an underdrain.
That distinction matters in a town where modest additions and driveway expansions trigger review. An overlay on an existing slab is neither: it changes the finish, not the hydrology, because the water still leaves over the concrete below.
Princeton's thresholds are tighter than the state's
Princeton's stormwater ordinance, in sections T10B-227 to 227.13 of the land use chapter, was adopted in 2020 and amended by Ord. 2023-33. It defines a major development as disturbing half an acre or more, or increasing impervious surface by 5,000 square feet or more, measured cumulatively since February 2, 2004. A minor development is any increase of 400 square feet or more of impervious surface that is not major, and minor developments follow the small-project standards in Article XI. Projects of that size that need no site plan review are small projects, counted since June 12, 2017, and follow the same standards. The ordinance covers residential and nonresidential applications, except aspects preempted by the Residential Site Improvement Standards.
Major developments must use low impact design and green infrastructure to meet the state recharge, quality and quantity standards. The state lists the pervious paving system as green infrastructure, but the BMP Manual's named surface courses are porous asphalt, pervious concrete and pavers, so resin-bound would be reviewed as an alternative measure under N.J.A.C. 7:8-5.2(g). Major site plan and major subdivision applications also include the municipality's Green Development Information Statement and Checklist.
Soils, streams and frost: notes for the project engineer
Infiltration varies widely across Princeton, from better-drained ground to tighter, clay-rich soils over shale, and the Stony Brook and Millstone River corridors carry floodplain and high-groundwater constraints. The state rules require 2 feet of separation from the seasonal high water table or bedrock for an infiltrating pervious system, 1 foot where it is underdrained. Expect the reviewer to want soil testing at the actual footprint, and a slower native soil usually means an underdrain.
The BMP Manual caps the surface slope at 5 percent, requires the stone bed to empty within 72 hours and limits run-on to three times the system's area. It also prohibits stockpiling sanded or salted snow on the surface. Whether the base above it is Rock Crete or open-graded stone, the reservoir depth should come from the engineer's storage and frost calculations, not a standard detail.
Where Princeton projects use it
Because porous surfaces still count as impervious here, the best uses are places where the stone reservoir does real storage work:
- Residential additions and driveway widenings that cross 400 square feet and need on-site management under the small-project standards.
- Courtyards, walks and plazas on academic, research and private school campuses, where a natural stone look suits older buildings.
- Rear courts and service areas behind the Nassau Street and Witherspoon Street commercial blocks.
- Parking areas at churches, clubs and nonprofit sites in the former township, where redevelopment may cross the 5,000-square-foot line.
Review in Princeton and how Resin Rock supports it
The Planning Board or Zoning Board of Adjustment is the board of jurisdiction for site plans, with the municipal engineer reviewing the stormwater design; minor projects that need no board approval are reviewed through the engineering and zoning permit process. Ask early how the engineer will treat a resin-bound surface course, since the code's impervious definition and the BMP Manual's named surfaces both point to an alternative-measure review.
Resin Rock supplies the resin binder, stone blends, trims and Rock Crete base, along with technical data sheets for the submission. We do not install. We match owners with an approved installer, usually within a day, and train New Jersey crews through installer training. Approval and any stormwater credit rest with the reviewer.
Before you specify permeable resin-bound in Princeton
- Add up new impervious surface, counting porous paving, against the 400 and 5,000 square foot lines, and ask whether your count starts in 2004 or June 2017.
- Test infiltration and seasonal high water table where the system will sit.
- Keep the finished surface at or below a 5 percent slope.
- Ask the municipal engineer how a resin-bound surface course will be reviewed.
- For site plan or subdivision applications, complete the Green Development Information Statement and Checklist.
- Plan maintenance and snow storage off the permeable area.
Common questions about permeable resin-bound in Princeton
Will a permeable resin-bound driveway reduce my impervious coverage in Princeton?
Not under the stormwater ordinance's definitions, which list porous asphalt and porous concrete as impervious surfaces. A permeable resin-bound section is likely to be treated the same way. What it can do is store and treat runoff in its stone base, which may help meet the stormwater standards that the added coverage triggers. Confirm treatment with the municipal engineer.
My addition adds 450 square feet of roof and patio. Do I need stormwater management?
Probably. Princeton applies its small-project stormwater standards to any increase of 400 square feet or more of impervious surface, counted since June 12, 2017 for projects without site plan review and since February 2, 2004 for those with it. The usual route is a permeable patio over a stone bed, a rain garden or another listed green infrastructure practice. Princeton allows a dry well only when those cannot meet the requirement.
Does Princeton charge a stormwater fee with credits?
We did not find a Princeton stormwater utility fee in this research. New Jersey law allows towns to create one, and any utility must offer credits for maintained green infrastructure. Until a fee is adopted there is nothing to credit, so judge the project on meeting the ordinance and on drainage performance.
Official sources for Princeton
- Princeton Code T10B-227.1 Stormwater management definitions and applicability
- Princeton Code Chapter T10B Land Use (attachments include the Green Development checklist)
- N.J.A.C. 7:8 Stormwater Management Rules (NJDEP courtesy copy)
- NJ Stormwater BMP Manual, Chapter 9.6 Pervious Paving Systems (January 2026)
Local rules change. We last checked these sources in October 2026. Confirm current requirements with the reviewing agency before you design, and treat this page as a starting point, not engineering or permitting advice.