Texas Bays and Estuaries: A Freshwater Destination

Full use of freshwater resources authorized for withdrawal could result in severe problems for estuaries.

The coastal wetlands and estuaries along the Texas coast provide rich habitat for numerous bird species and are nurseries for saltwater fish, crabs, shrimp and shellfish. The success of these wetlands depends upon having the right amount of freshwater mixing with the Gulf of Mexico's saltwater in the estuary. Most major Texas rivers flow to coastal estuaries, and it is through these rivers and streams that the flow of freshwater helps maintain a fragile balance of water chemistry that sustains many specially-adapted plants and animals (TPWD, 2009).

Unfortunately, the right amount of freshwater does not always flow to these estuaries. To meet inland water demands for communities, irrigation and industry, water is withdrawn from rivers upstream, leaving less water for the coast. As the Texas population continues to grow, so does the demand for fresh water. It is anticipated that in the near future, the water authorized for withdrawal will be in full use.

The chart below presents results from a study by the National Wildlife Federation that forecasts the condition of seven major estuaries where freshwater input is critical. The Bays in Peril Report found that of seven estuaries studied, five are expected to experience severe health problems if freshwater needs are not met.

Forecasted condition of 7 major estuaries in Texas View Larger Image. Forecasted condition of seven major estuaries in Texas. In the Bays in Peril Report, the National Wildlife Federation forecasts what would happen to the inflows to Texas' seven major bays and estuaries if existing water permits were in full use and wastewater resuse increased.

Aransas

White ibis in the Aransas National Wildlife Refuge, Texas. Credit: U.S. Fish and Wildlife Service.


For more information:

Texas, the State of Flowing Water Documentary Series

NOAA's National Estuarine Research Reserve System

Diving Deeper: Estuaries Podcast

Closer Look

Relevant Links

U.S. Geological Survey Water Use in the United States
http://water.usgs.gov/watuse/