New York State Waterbody Quality Classifications

New York State's Department of Environmental Conservation provides official water quality classifications for lakes, rivers, streams, and ponds across the state. The dataset assigns legal classifications based on existing or expected best usage, determining protection levels under state law. It is published by data.ny.gov and was last updated in early April 2026.

Use Cases

• Mapping protected streams by filtering for waterbodies with a 'Water Quality Class' of C (T) or higher.
• Analyzing waterbody distribution by 'Basin' and 'Waterbody Type' for regional resource assessments.
• Linking specific waterbody segments via 'Segment ID' or 'Waterbody Index Number (WIN)' to other environmental datasets.
• Calculating total protected stream mileage within a basin using the 'Segment Miles' column for regulatory reporting.

Strengths

• Includes a specific legal reference ('6NYCRR Chapter X Part') for each classification, enabling precise regulatory tracing.
• Provides unique identifiers ('Segment ID', 'Waterbody Index Number (WIN)') for unambiguous record linkage across systems.
• Covers all classified waterbodies in New York State, offering a complete inventory for regulatory purposes.

Limitations

• Key metrics like total row count and dataset size are unreported across all sources, obscuring its scale.
• The 'last updated' date conflicts between sources (2026-04-04 vs 2026-04-03), casting doubt on update frequency.

Provenance

Source

New York State Department of Environmental Conservation (via data.ny.gov).

Collection Method

Official administrative classification under New York State's Environmental Conservation Law.

Freshness

2026-04-04

Geography

All waterbodies within New York State.