Preliminary Healthy Watersheds Assessments
The EPA Healthy Watersheds Program developed Preliminary Healthy Watersheds Assessments (PHWA) in 2017 in support of states' and other partners' efforts to identify and protect high quality waters. EPA released an update to the PHWA in 2021 and 2025.
The PHWA project is a set of 48 statewide and 85 ecoregional-scale assessments that score watershed health and vulnerability across the conterminous United States. The assessment was based on the Healthy Watersheds Assessment Framework, an analytical approach that focuses on six key attributes of watershed health: Landscape Condition, Geomorphology, Habitat, Water Quality, Hydrology, and Biological Condition. In addition to characterizing watershed health, the PHWA also includes estimates of relative watershed vulnerability, defined as the potential for future degradation of watershed processes and aquatic system health.
2025 Update to the PHWA
EPA included updated PHWA watershed health and vulnerability scores in Version 2.8 of the Restoration and Protection Screening Indicator Database, released in May 2025. Updated 2025 PHWA scores are also available in state Restoration and Protection Screening Tools.
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Click here for an overview document that describes the 2025 update to PHWA.
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Click here for an Excel data file containing 2025 PHWA indicator definitions, metadata, and lists of specific indicators used in statewide and ecoregional assessments.
Original 2017 PHWA Data Downloads
Choose a state from the map below. Find your assessment copy in your computer's downloads folder, then open it offline. Please note that there is no file associated with AS, DC, GU, MP and TT at this time.
