Hydrologists study all aspects of water and its relation to geography, geology, biology, and chemistry. Of greatest interest currently is how to keep our streams, lakes, reservoirs, and subsurface water supplies from being polluted, and how to clean up the water that has already been contaminated with a variety of inorganic and organic chemicals. As scientists, hydrologists are always interested in how water moves through the hydrologic cycle and where in the cycle water is most vulnerable to degradation. Hydrologists use many tools to do their work, from shovels to mass spectrometers, and new tools are being developed every day.
Computers undoubtedly are the most used tool.
Most States also employ hydrologists in their Department of Natural Resources or Department of Environmental Quality, and more and more counties are employing hydrologists to keep track of water distribution and water use in their districts. The annual salary of hydrologists depends upon experience and academic training. Today, many universities and colleges offer undergraduate and graduate degrees in hydrology or environmental science. The role of the USGS has grown along with the changing needs of the country, and the USGS has diversified to include not only a Geologic Division and a National Mapping Division, but also a Water Resources Division and a Biologic Resources Division. Of course there is some overlap among the divisions, which is why we all work together and are collectively known as the U.S. Geological Survey.