From your tap to the world around it

Water connects
everything.

Explore the waters around a place. Move across the map, follow a stream, and discover the records behind a shoreline.

The water atlasUnited States · EPA assessments

A wider perspective

Follow the water.

Explore rivers, lakes and coastlines across the United States.

Reported impairedOther assessment statusNot assessed / unknown

Shading follows assessment boundaries, which may include land. The zoomed-out overview is a national snapshot rendered on 2026-09-16; zoom in for current records. These are not live readings or swimming advisories. Unmarked does not mean clean. About the data

The atlas needs JavaScript. You can explore the same official source in EPA How’s My Waterway or browse drinking-water records by state.

A more recent reading

Find monitoring stations
around a place.

County pages now check USGS for available observations from the last 48 hours. Explore temperature, dissolved oxygen, pH, turbidity, conductivity, streamflow or water level where stations report them. The time and unit stay with every reading.

These station measurements and the EPA assessment map describe different things. Neither determines the safety of your tap or a swimming spot.

Search a city or county, then open Recent station readings on its overview.

Cecil County, MD Anne Arundel County, MD Fairfax County, VA

Read the landscape. Understand the record.

A map with context.

The atlas brings EPA’s published waterbody assessments into a geographic view. Select a region and zoom in to load records for that area.

Looking for drinking-water records?

What the colors mean

Ochre marks a waterbody reported as impaired. Teal means another reported assessment status; it is not a “safe” rating. Gray means not assessed or unknown. Shaded areas are reported assessment boundaries and may extend beyond the physical water. An assessment can cover more than one waterbody type.

Rivers, lakes, and coastal waters

Coverage includes waterbodies that states, tribes and territories have reported to EPA. Bays, estuaries, lagoons and some ocean shorelines can be included. This is not a global survey of the open ocean, and unmarked waters may have no published assessment in this source.

Assessment cycles, not live alerts

States report conditions over assessment cycles. Those records can be older than current conditions. Use local agencies for current swimming, fish-consumption or emergency advisories.

Follow the original source

Assessments: EPA ATTAINS. Detailed reports: How’s My Waterway. Map geography: Esri World Light Gray Canvas by Esri. Geography and assessment coverage are different layers.

Water connectseverything.