Runoff

The Southwest, Great Plains, and Southeast are particularly vulnerable to changes in water supply and demand. Changes in precipitation and runoff, combined with changes in consumption and withdrawal, have reduced surface and groundwater supplies in many areas. These trends are expected to continue, increasing the likelihood of water shortages for many uses.

The primary culprits in eutrophication appear to be excess nitrogen and phosphorus—from sources including fertilizer runoff and septic system effluent to atmospheric fallout from burning fossil fuels—which enter waterbodies and fuel the overgrowth of algae, which, in turn, reduces water quality and degrades estuarine and coastal ecosystems.

Runoff from upstream development had almost destroyed all aquatic life in the stream.

These runoff elections will decide who will gain control of the Senate.

The dead zone’s expansion is believed to be driven by pollutant runoff from farms and cities contaminating the Mississippi River, which flows into the Gulf of Mexico and stimulates oxygen-consuming algae growth.

The runoff ended up infiltrating into the permeable soil.

Algal overload is common in waterways worldwide caused by fertilizer runoff and poor sewage management.

The sprawling watershed, where the Potomac and several other great rivers merge on their way to the Atlantic Ocean, stretches over 166,000 square kilometers and encompasses six Atlantic coast states and the nation's capital. It nourishes a multitude of marine and terrestrial wildlife. It's the source of fresh drinking water, food and recreation for 17 million people. But in recent decades, rapid population growth, farm chemical runoff and industrial activity have polluted the bay and upset the watershed's delicate ecology.

Oyster reefs harbor huge amounts of life. Scores of plants and animals find food and shelter in their nooks and crannies. As the Bay's reefs wore down, that habitat was lost. Further damage came from increasing runoff from coastal farmland, deforestation and development, which silted over the flatter oyster bars, cutting off the creatures' food and dissolved oxygen. Then, in the mid-1900s came the final assault — a pair of parasites.

Although no one is predicting a total meltoff all at once, keeping an eye on ice formation, runoff amounts and how the water is moving is critical to accurately predicting sea level changes.