Water Science School

Surface Water

The world's surface-water resources—the water in rivers, lakes, and ice and snow—are vitally important to the everyday life of not only people, but to all life on, in, and above the Earth. And, of course, surface water is an intricate part of the water cycle, on which all life depends.

All Surface Water Science Topics

All Surface Water Science Topics

View a list of all of our science topics about surface water.

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Surface Water and the Water Cycle

Surface Water and the Water Cycle

The various forms of surface water are integral parts of the natural water cycle.

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Filter Total Items: 42
Date published: June 8, 2018
Status: Completed

Uses of Streamflow Information

The U.S. Geological Survey (USGS) has been measuring the amount of water flowing in rivers since the 19th century. Having reliable past and present streamflow information is vital for many reasons, both at the personal and national level. 

Contacts: Ask USGS
Date published: June 8, 2018
Status: Completed

How Wet is Your State? The Water Area of Each State

What percent of your state do you think is water covered? Which state has the highest percentage of water area? Is the West really "drier" than the rest of the country?

Contacts: Ask USGS
Date published: June 8, 2018
Status: Completed

Floods: Things to Know

The following topics provide background on some of the scientific issues regarding floods.

Contacts: Ask USGS
Date published: June 8, 2018
Status: Completed

Droughts: Things to Know

The following topics provide background on some of the scientific issues regarding droughts.

Contacts: Ask USGS
Date published: June 8, 2018
Status: Completed

Glaciers: Things to Know

The following topics provide background on some of the scientific issues regarding glaciers.

Contacts: Ask USGS
Date published: June 7, 2018
Status: Completed

The 100-Year Flood

A 100-year flood happened last year so it won't happen for another 99 years, right? Not exactly. Misinterpretation of terminology often leads to confusion about flood recurrence intervals. Read on to learn more.

Contacts: Ask USGS
Date published: June 6, 2018
Status: Completed

How Much Water Flows During a Storm?

If a low-lying area near a river near you usually gets about 50 inches of rain a year, you might think "Well, that is about 1 inch per week, so that won't cause any flooding". But, nature doesn't think the same way, and often a large percentage of a year's precipitation can fall in a major storm, in a single day. Your river might not react much to a 1 inch rain, but things might be much...

Contacts: Ask USGS
Date published: June 6, 2018
Status: Completed

Runoff: Surface and Overland Water Runoff

When rain falls onto the landscape, it doesn't just sit there and wait to be evaporated by the sun or lapped up by the local wildlife—it begins to move (due to gravity). Some of it seeps into the ground to refresh groundwater, but most of it flows down gradient as surface runoff. Runoff is an intricate part of the natural water cycle.

Contacts: Ask USGS
Date published: June 6, 2018
Status: Completed

Rivers Contain Groundwater

Naturally, the water running in rivers comes from precipitation that runs off the landscape into the river. But since precipitation also seeps into (and moves) into the ground, you don't often consider that a significant amount of the water flowing in rivers comes from water in the ground seeping back "up" into the river from below. 

Contacts: Ask USGS
Attribution: Water Resources
Date published: June 6, 2018
Status: Completed

Rivers and the Landscape

Creeks and streams begin their lives as smaller water bodies that run downhill until they merge to form bigger rivers. Rivers are a mighty factor when it comes to shaping the physical landscape — just ask the Grand Canyon. Find out more here.

Contacts: Ask USGS
Date published: June 6, 2018
Status: Completed

Lakes and Reservoirs

A lake really is just another component of Earth's surface water. A lake is where surface-water runoff and groundwater seepage have accumulated in a low spot, relative to the surrounding countryside.

Contacts: Ask USGS
Date published: June 6, 2018
Status: Completed

Crest Gage: A Quick Way to Measure River Stage

The maximum height rivers reach during storms and floods is an important "data point" to document. In places where there are not dedicated monitoring equipment, the U.S. Geological Survey (USGS) often uses "crest stage gages" to record a one-time measurement of the flood peak.

Contacts: Ask USGS
Attribution: Water Resources