Transformative Measures for Sustainable Stormwater Management In NYC
About 60% of New York City operates on a combined sewer system, channeling both stormwater runoff and sewage from buildings through a single pipeline. When heavy rainfall occurs, the system activates combined sewer overflows (CSOs), directing untreated sewage into rivers and water bodies to prevent building flooding. Environmental concerns arise, especially as rising greenhouse gas emissions increase extreme weather events, contributing to water pollution issues.
DEP's Commitment to Climate Resilience:
Evolution of Stormwater Management Rules
As part of New York City’s broader climate change mitigation efforts, the Department of Environmental Protection (DEP) is actively engaged in stormwater resiliency planning. This commitment involves strategic investments, policy changes, a focus on green infrastructure, and on-site stormwater management to address the challenges posed by climate change.
Unveiling the 2022 Unified Stormwater Rule:
How it Affects Building in NYC
The Unified Stormwater Rule (USWR), effective since February 15th, 2022, introduces pivotal amendments to Chapter 31 and Chapter 19.1 of NYC’s Rules. These changes significantly impact citywide stormwater management requirements for both new construction and redevelopment projects. The revisions in Chapter 31 address updated stormwater quantity and flow requirements, integrating technical specifications for Site and House Connection Proposals. Meanwhile, Chapter 19.1 expands the Stormwater Construction Permitting Program, emphasizing on-site stormwater detention, release rate requirements, and a retention-first approach in post-construction stormwater management practices (SMPs). The rule promotes sustainable green infrastructure, influencing re-development projects exceeding 20,000 sq ft.
Owners seeking to connect to a City sewer, private sewer, private drain, or an approved outlet for an existing or proposed development are still required to submit a sewer certification application. Sewer availability certification applications now necessitate the inclusion of specific components. These include:
These details must align with the NYC Stormwater Manual and Chapter 31 requirements. Site plans submitted with the certification applications must outline the proposed stormwater management facilities essential for on-site retention and/or detention of stormwater runoff, ensuring adherence to the Unified States Water Resources (USWR) and Chapter 19.1 standards. The NYC Stormwater Manual serves as a comprehensive guide, specifying the requirements for implementing effective stormwater management practices as mandated by Chapter 31.
Navigating the Changes:
The Role of the New NYC Stormwater Manual (SWM)
In parallel with the amendments to Chapter 19.1, the introduction of the NYC Stormwater Manual (SWM) stands as a critical guide for industry professionals. Tailored for developers, designers, and engineers collaborating with the DEP on stormwater permits, the SWM provides a comprehensive overview of essential practices aligned with the evolving stormwater management regulations. This guide not only aids in compliance but also serves as a catalyst for innovation, encouraging the implementation of sustainable stormwater solutions in a rapidly changing regulatory landscape.
NYC Civil Engineers
Civil engineers are essential contributors to the successful implementation of NYC’s USWR, playing a pivotal role in fostering resilient and sustainable stormwater management practices. From ensuring that proposed developments comply with the updated stormwater quantity and flow requirements to the technical specifications for Site and House Connection Proposals, we support the integration of sustainable and innovative stormwater management practices. This includes aligning with the retention-first approach emphasized in post-construction stormwater management practices (SMPs) under Chapter 19.1.
