How NYC DEP Updates Will Impact the City’s Construction Industry

24 May, 2022
  • New New York City Department of Environmental Protection (NYC DEP) regulations address the volume of water and contaminants entering its aging sewer system.
  • Under the new Unified Stormwater Rule (USWR), developers are likely to incur greater costs for larger detention basins and/or green initiatives like rain gardens and green roofs.
  • Developments reaching a 20,000-SF disturbance threshold or increasing impervious coverage by 5,000 SF or more are now required to design and permit a Stormwater Pollution Prevention Plan (SWPPP) – a substantial change from previous regulations.
  • Engaging a site civil engineering consultant early in the project lifecycle can help developers understand their options and make more informed decisions.

Struggling City Infrastructure

Much of New York City’s underground sewer system was built in the 1920s and 30s. In general, the system is combined, with both sewer water and stormwater flowing together into treatment plants across the City. Rising population density throughout the five boroughs and increased rainfall is stretching the existing infrastructure beyond its limits.

To alleviate the burden on the aging infrastructure, the City’s Department of Environmental Protection (NYC DEP) is restricting the amount of stormwater an individual property can discharge into the system and mandating certain pollution mitigation efforts.

On February 15, 2022, the agency issued the Unified Stormwater Rule (USWR), which introduced new regulations regarding storm sewer connections, wastewater treatment, and Stormwater Pollution Prevention Plans (SWPPP). The updated requirements impact all outstanding NYC DEP applications as of February 15.

For developers, these changes mean that one of the nation’s most expensive places to build could be even costlier. Here’s how recent regulation changes are impacting development decisions and budgets.

Reducing the Burden

To reduce the volume of water entering the system, properties are now required to store more stormwater on site for longer. Additionally, there must be a more gradual release of the stormwater to the public system. In general, developers and design teams can accomplish this in one of two ways:

Option 1: Larger Detention Tanks

Most urban developments rely on underground storage tanks to satisfy stormwater management requirements. Under the new regulations, these tanks will need greater capacity to hold more stormwater. While larger detention tanks cost more and require structural coordination so the building can support a larger tank, this option is often the easiest to implement.

Option 2: Green Initiatives Like Rain Gardens, Bioswales, and Green Roofs

NYC DEP joins many regulatory agencies across the nation in encouraging owners and developers to incorporate sustainable features to hold and treat stormwater naturally. Rain gardens, bioswales, and green roofs often require a higher upfront cost as well as significant long-term maintenance to ensure they continue working properly. While the city is not currently offering any substantial development or financial incentives to implement these solutions, sustainable design features can bring long-term value to the site. Over time, these features can reduce energy costs for cooling, add aesthetic value, and incentivize prospective tenants that value green energy practices.

Mitigating Pollution

The second part of NYC DEP’s strategy is to better mitigate pollution before stormwater reaches treatment plants. The agency is doing this by requiring a greater number of land development projects to have a Stormwater Pollution Prevention Plan (SWPPP).

Under the new regulations, a NYC DEP-approved SWPPP is required for any project disturbing more than 20,000 SF of land or increasing impervious coverage by 5,000 SF. In addition to the disturbance on site, developments that require right-of-way improvements will need to factor in street work to the total area disturbed, according to the update.


A Stormwater Pollution Prevention Plan (SWPPP) is a site-specific plan developed by a site civil engineer to address stormwater management and contamination during construction. The plan must be reviewed and approved by NYC DEP. During construction, a certified professional must visit the site regularly to inspect and record that the management practices are working properly.

Previously, only projects disturbing one acre (43,560 SF) or more were required to have such plans. The NYC DEP’s regulation change will make more projects subject to the SWPPP requirement.


What This Means for Development Teams

If a project meets the new disturbance threshold, developers will need to engage a site civil engineer to prepare a SWPPP plan and report for NYC DEP to review and approve. These documents illustrate how stormwater will be managed on site during construction to limit pollution, as well as permanent measures that will be taken post-construction. The process also includes:

  • Weekly inspections during construction by a certified professional. Large sites could require inspections twice per week. The site is subject to NYC DEP inspection at any time throughout construction, so adherence to the SWPPP is essential to avoid fines, penalties, or orders to stop construction.
  • Permanent water quality devices must be incorporated into the site’s stormwater management design to treat the water prior to release into the public system.

New guidelines for post-construction maintenance, inspections, and SWPPP permit renewal have also been released in the regulation update. The owner or property manager will be responsible for

  • Annual inspections and reporting to the NYC DEP,
  • Post-construction permit renewal every five years, and
  • Long-term maintenance to ensure filtration devices are working properly.

Maintaining Momentum With NYC DEP Approvals

Since the regulations are environmentally related, fines for failing to comply will be hefty. Additionally, sewer connections will not be approved without proof of SWPPP approvals. Construction will be shut down if your contractor attempts to pull a tap permit without the proper documentation.

While SWPPP permitting can be done concurrently with standard site plan submissions, Bohler’s team is monitoring how the NYC DEP will manage the influx of applications. Engage an experienced site design and permitting team that can streamline and strategize entitlements and keep your project on track.

Questions about NYC DEP or SWPPP plans and permitting?

Contact Jared

How NYC DEP Updates Will Impact the City’s Construction Industry

24 May, 2022

About Jared Jones, PE

Jared is an Associate in Bohler’s Manhattan, NY office. He leads a team of site civil engineering professionals who help owners and developers leverage industry change and tackle site challenges to accomplish their land development goals. Throughout his 15-year career, Jared has guided a variety of clients through New York City’s complex design and permitting processes, identifying cost and time-saving opportunities to help offset rising construction costs. Jared drives the land development process and is focused on bringing quality projects to life as quickly as possible.

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