Here you will find information about the quality of Montana's rivers, streams, and lakes in relation to Montana's Water Quality assessments. These assessments are derived from available statewide water monitoring data and information. The Clean Water Act Information Center also provides access to Montana's Water Quality Reports and List of Impaired Surface Waters, as well as online search and mapping tools.

Search Water Quality Data

View information about the quality of Montana's rivers, streams, and lakes in relation to water quality standards.

Montana Water Quality Reports

View Montana's Water Quality Integrated Report, list of impaired waters, waters in need of Total Maximum Daily Load (TMDL) studies, and beneficial use support changes.