Contaminant Transport Modeling

Centennial Streamgages are USGS streamgages that have been in operation for more than 100 years.

From the second half of the 19th century, land reclamation has transformed the Sacramento-San Joaquin Delta (Delta). The landscape of the Delta has gone from a network of shifting waterways and tidal marshland to channels and islands fixed in position by hardened levees.

In 2019, the USGS began a water-quality monitoring program in Lake Koocanusa (also known as Koocanusa Reservoir) and at a site on the Kootenai River downstream of Libby Dam to provide high-frequency water-quality data for Federal, State, Provincial, and Tribal entities in the United States and Canada.

MODFLOW is the USGS's modular hydrologic model. MODFLOW is considered an international standard for simulating and predicting groundwater conditions and groundwater/surface-water interactions. MODFLOW 6 is presently the core MODFLOW version distributed by the USGS. The previous core version, MODFLOW-2005, is actively maintained and supported as well.

The U.S. Geological Survey is integrating its water science programs to better address the Nation’s greatest water resource challenges. At the heart of this effort are plans to intensively study at least 10 Integrated Water Science (IWS) basins — medium-sized watersheds (10,000-20,000 square miles) and underlying aquifers — over the next decade. The IWS basins will represent a wide range of...

The USGS Groundwater and Streamflow Information Program supports the collection and (or) delivery of both streamflow and water-level information at approximately 8,500 sites and water-level information alone for more than 1,700 additional sites. The data are served online—most in near realtime—to meet many diverse needs.

The Next Generation Water Observing System provides high-fidelity, real-time data on water quantity, quality, and use to support modern water prediction and decision-support systems that are necessary for informing water operations on a daily basis and decision-making during water emergencies. The Illinois River Basin provides an opportunity to implement the NGWOS in a system challenged by an...

Our surface water, groundwater, and aquatic ecosystems are priceless resources, used by people across the Nation for drinking, irrigation, industry, and recreation. The National Water-Quality Assessment (NAWQA) Project is a leading source of scientific data and knowledge for development of science-based policies and management strategies to improve and protect our water resources.

The enhanced probability of catastrophic wildfires has increased our need to understand the risk of floods, erosion, and debris and contaminant transport in burned watersheds. This project investigates the relation between rainfall intensity and peak discharge; erosion and deposition processes; and water-quality impacts to minimize the loss of life and property resulting from post-wildfire floods.

The USGS has been at the forefront of studying the impacts of acid rain for decades. How does acid rain form? What does it do to the landscape? Can it burn you like battery acid? Keep reading to find out more...

Oil spills, such as the 2010 Deepwater Horizon Oil Spill, are impactful environmental disasters that have long lasting effects to the landscape, native species, and inhabitants who depend on the area. The USGS explores the adverse effect that large-scale oil spills have on the environment and helps responders prepare for environmental recovery and rehabilitation.

Sealcoat is the black, viscous liquid applied to many asphalt parking lots, driveways, and playgrounds in North America to protect and enhance the appearance of the underlying asphalt. Coal-tar-based pavement sealcoat is a potent source of polycyclic aromatic hydrocarbon (PAH) contamination in urban and suburban areas and a potential concern for human health and aquatic life.