Hydrographic and Impairment Statistics Database: NPS Water Quality Tracking

Hydrographic and Impairment Statistics (HIS) is a National Park Service project tracking Clean Water Act compliance goals. It inventories impaired waters and hydrographic features using GIS, based on USGS National Hydrography Dataset and state GIS layers. The data was last updated on 2026-03-04.

Use Cases

• Tracking compliance with Clean Water Act water quality standards based on impairment status.
• Analyzing hydrographic statistics for managed surface waters based on the National Hydrography Dataset.
• Mapping impaired waters and their causes for environmental management based on GIS inventory.
• Evaluating waterbody condition for Section 303(d) of the Clean Water Act based on impairment data.

Strengths

• Data is based on the authoritative USGS National Hydrography Dataset.
• Project is established to track specific Government Performance and Results Act goals.
• Analysis combines 1:24,000 scale NHD data with finer-scale state GIS layers.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• Freshness should be verified as the last update date is 2026-03-04.

Provenance

Source

National Park Service Water Resources Division, Department of the Interior

Collection Method

Inventory and monitoring in a geographic information system.

Freshness

Last updated 2026-03-04 01:32:44.149501

Geography

United States (National Park Service managed lands)