Althea A. Archer, PhD

Vintage-style poster of the Delaware River near the Delaware Water Gap with a USGS gage on the bridge in the foreground. Poster created for WMA Great American Waterways Campaign.

Illustration by Althea A. Archer, USGS

Vintage-style poster of Chesapeake Bay with a USGS gage and blue crab on the shoreline in the foreground and estuaries feeding the bay the background. Illustration by Althea A. Archer, USGS  Poster created for WMA Great American Waterways Campaign.

Illustration by Althea A. Archer, USGS

Vintage-style poster of St. Anthony Falls on the Mississippi River showing a streamgage in the foreground. Illustration by Althea A. Archer, USGS. Poster created for WMA Great American Waterways Campaign.

Illustration by Althea A. Archer, USGS

Vintage-style poster of a Great Lake during sunset with a USGS streamgage in the foreground on the shore. Poster created for WMA Great American Waterways Campaign.

Illustration by Althea A. Archer, USGS

Vintage-style poster of the Colorado River with a USGS water quality monitor portrayed on pulleys across the canyon. Poster created for WMA Great American Waterways Campaign. 

Illustration by Althea A. Archer, USGS 

Vintage-style poster of the Columbia River flowing alongside Mount Hood with a USGS streamgage featured in the foreground. Poster created for WMA Great American Waterways Campaign. Illustration by Althea A. Archer, USGS

Diagram of a typical streamgage installation with equipment used to measure stream stage

Diagram of how USGS water data are transferred from streamgage to the internet 

Illustration of Drippy, USGS Water's unofficial mascot, splashing out of a drain pipe into a sewer with a lollipop in his hand. This illustration was used to represent the USGS study of artificial sweeteners as they enter the water cycle.

Map of the Upper Colorado River Basin —referred to as an Integrated Water Science (IWS) basins—are intensively monitored study basins representing a wide range of environmental, hydrologic, and landscape settings and human stressors of water resources to improve our understanding of water availability across the Nation.

The U.S. Geological Survey uses a depiction and classification scheme for hydrologic units known as hydrologic unit codes (HUCs). HUCs generally represent catchments, and river basins are represented by a unique series of numbers with successively smaller hydrologic units nested inside of larger ones.

Around 90% of daily water use in the lower 48 United States goes toward crop irrigation, thermoelectric power plants, where freshwater is used in the process of creating energy, and public supply, where water is withdrawn or purchased by a water supplier and delivered to many users. These three uses add up to 224,000 million gallons of freshwater per day.

Water limitation across the lower 48. Water limitation is measured as the Supply and Use Index (SUI) which represents the imbalance between water supply and demand. A higher SUI indicates a greater proportion of supply being used. 

Diagram of the process of water use from source (surface water, groundwater, reuse water) through transmission, utility reservoir, water treatment, distribution, and withdrawal for industry, residential, and commercial.

A cross-sectional view of a hypothetical coastline showing one possible arrangement of the three Federal Flood Risk Management Standard (FFRMS) floodplain elevations (Climate-Informed Science Approach, the Freeboard Value Approach, and the 0.2% Annual-Chance Flood Approach) above the current Base Flood Elevation, i.e., the 1% annual-chance flood elevation.

A cross-sectional view of a hypothetical river showing one possible arrangement of the three Federal Flood Risk Management Standard (FFRMS) floodplain elevations (Climate-Informed Science Approach, the Freeboard Value Approach, and the 0.2% Annual-Chance Flood Approach) above the current Base Flood Elevation, i.e., the 1% annual-chance flood elevation.

A cross-sectional view of a hypothetical river showing one possible arrangement of the three Federal Flood Risk Management Standard (FFRMS) floodplain elevations (Climate-Informed Science Approach, the Freeboard Value Approach, and the 0.2% Annual-Chance Flood Approach) above the current Base Flood Elevation, i.e., the 1% annual-chance flood elevation.

A cross-sectional view of a hypothetical coastline showing one possible arrangement of the three Federal Flood Risk Management Standard (FFRMS) floodplain elevations (Climate-Informed Science Approach, the Freeboard Value Approach, and the 0.2% Annual-Chance Flood Approach) above the current Base Flood Elevation, i.e., the 1% annual-chance flood elevation.

A timeseries of monthly Oceanic Niño Index values from 1950 to 2023. The y-axis is mirrored at 0, with positive teal values indicating el Niño periods and negative lavender values corresponding to la Niña periods. The chart sits over a watercolor wash that has a gradient from teal at the top to lavender at the bottom.

Animation showing changes in stream temperature relative to air temperature over the course of a day. The animation begins at midnight, adding a point at each half-hour interval. After dawn, as air temperature starts warming, the stream warms more slowly than air, and water temperature lags behind air temperature.

A scatter plot of water temperature versus air temperature on April 27, 2019, for the Paine Run stream in Shenandoah National Park. Points are plotted for each 30-minute interval. Daytime points are hollow, while nighttime points are solid.