SW

Stormwater Directory

New York

New York State Department of Environmental Conservation

Quick Summary

For most New York projects disturbing 1 acre or more, you need a SPDES Construction General Permit filed online through the state eNOI system. Sites 5 acres or larger require a licensed PE to sign the SWPPP. The flat permit fee of $2,250 is the highest in the country.

State-DelegatedVerified 2026-03

Construction Permit

Permit Document
Permit Name
SPDES General Permit for Stormwater Discharges from Construction Activity (GP-0-25-001)
Threshold
≥ 1 acre of land disturbance (or < 1 acre if part of a larger common plan). NYC East of Hudson watershed: ≥ 5,000 sq ft. City of New York municipal boundaries: ≥ 20,000 sq ft.
NOI Lead Time
Electronic NOI (eNOI) required; NYSDEC issues a Letter of Authorization (LOA) specifying the authorized construction start date
Application Method
Online via NYSDEC's eDEC system — electronic eNOI submission now mandatory (paper no longer accepted)
Fee
$2,250 flat fee for most projects (one of the higher fees nationally)
Permit Expires
January 28, 2030

SWPPP Requirements

Permit Document
SWPPP Required
Yes
PE Cert Required
Yes
Template Available
Yes
New York requires a licensed Professional Engineer (PE) or Registered Landscape Architect (RLA) to prepare and certify the SWPPP for sites ≥ 5 acres. Sites < 5 acres may use a Qualified Inspector for preparation but must have a PE/RLA certify it if required by the local municipality.

Inspection Requirements

Permit Document
Frequency
Every 7 days and within 24 hours of a storm event producing ≥ 0.5 inches of rainfall (or ≥ 0.25 inches if site is near a 303(d) listed water body)
Rain Trigger
Within 24 hours of a storm event producing ≥ 0.5 inches of rainfall (≥ 0.25 inches if site drains to a 303(d) impaired water body)
Inspector Qualification
Trained Contractor (TC) for routine inspections; Qualified Inspector (QI) for sites ≥ 5 acres or near sensitive water bodies. QI certification required through NYSDEC-approved training.
Accepted Certifications
NYS DEC-approved erosion and sediment control training REQUIRED; CPESC, CESSWI explicitly listed as qualifying credentials in the SPDES CGP

Discharge Standards

Permit Document
Turbidity Limit
Not specified as a numeric standard; discharges must not cause or contribute to violations of water quality standards. Turbidity benchmarks apply for sites near 303(d)-listed waters.
Sites near 303(d)-listed water bodies or within a phosphorus-sensitive watershed trigger additional requirements including soil disturbance limits and more stringent BMPs.

Post-Construction

NYSDEC
Required
Yes
Projects that create ≥ 1 acre of impervious surface must implement post-construction stormwater management practices per the New York State Stormwater Management Design Manual. A long-term Operation and Maintenance Agreement may be required.

Impaired Waterbody / TMDL Requirements

Elevated Risk

New York's SPDES Construction Activity Permit (GP-0-20-001) includes specific provisions for projects near water bodies listed on the CWA 303(d) impaired waters list. Projects that discharge to impaired waters must implement additional BMPs consistent with any applicable TMDL wasteload allocations. Projects within New York City's primary watershed (Catskill/Delaware) face the most stringent requirements in the state. Check DEC's Waterbody Inventory/Priority Waterbodies List before permitting.

Program Contact

Contact Page

State-Specific Notes

New York's SPDES permit is state-specific (not NPDES) but federally equivalent. GP-0-25-001 took effect January 29, 2025, replacing GP-0-20-001. Key changes under the new permit: electronic eNOI submission via eDEC is now mandatory (paper no longer accepted); NYSDEC issues a Letter of Authorization (LOA) specifying the authorized construction start date; lower disturbance thresholds apply within the NYC East of Hudson watershed (≥ 5,000 sq ft) and within NYC municipal boundaries (≥ 20,000 sq ft). The $2,250 flat fee is among the highest in the country. NYC and surrounding counties may have additional local stormwater requirements. Operators who had coverage under GP-0-20-001 must obtain new authorization under GP-0-25-001 — coverage does not automatically transfer.

Disclaimer: This information is provided for general reference only and may not reflect the most current regulatory requirements. Always consult the NYSDEC website and applicable regulations before beginning any construction activity.