Urban Waters Federal Partnership - Suspended Sediment and Nutrient Delivery to the Gulf of Mexico

Science Center Objects

Suspended sediment and nutrients from greater San Antonio can affect instream ecological health of the San Antonio River and ultimately impact Gulf of Mexico bays and estuaries. Real-time monitoring in urban and rural parts of the river basin may provide a glimpse into the importance of urban sediment and nutrient sources. Real-time sensors provide a tool to better understand and manage water resources.

The City of San Antonio, Texas, and surrounding area is growing rapidly—one million people are predicted to move there in the next one to two decades. Urbanization can increase runoff, flash flooding, erosion, and contaminants in streams.

The San Antonio River is a jewel in the middle of the burgeoning city of San Antonio, Texas, and is the city’s most popular tourist attraction. The rural Medina River flows into the San Antonio River south of the city, and the San Antonio River is joined by the Guadalupe River just before it flows into San Antonio Bay, part of the Gulf of Mexico. How do activities within the City of San Antonio contribute to the ultimate load of sediment and nutrients, including nitrate, that is delivered to the Gulf?  The USGS, as part of the Urban Waters Federal Partnership, is solving that puzzle.

Many urban activities contribute sediment and nutrients to urban streams: home and commercial construction, demolition, road construction, stormwater, and wastewater all are potential sources. The EPA lists sediment as one of the most common pollutants in rivers, with nearly 70 percent of sediment pollution from human-accelerated erosion.

The USGS has upgraded a critical streamflow gaging station to a “Super Station” that measures streamflow, turbidity, nitrate, and other properties of water in real time. This site integrates the upstream urban tributaries, and data collected here can be compared to data from a gaging station that captures the rural component of the watershed. Participation in the Urban Waters Federal Partnership has been an important part of building the urban water hydrology program in the San Antonio area.

The project is being carried out in cooperation with San Antonio Water Systems (SAWS), San Antonio River Authority (SARA), and the City of San Antonio (COSA). Resources from the USGS Cooperative Funding program are being leveraged with local agencies to form a broad partnership. The USGS National Water Quality Assessment (NAWQA) Project has contributed to previous Urban Water activities. Funding from the EPA is being used to support an intern to work on the project.


More about other Urban Waters Federal Partnership projects