Latitude/Longitude:31.8521, -88.16107 Elevation:20 m Mean Annual Temperature:18C/64.4F Mean Annual Precipitation:1429 mm Dominant NLCD Classes:
USGS HUC: h03160201
Alluvial, coastal and terrace deposits. Holocene.
The surface water flow regime of the Lower Tombigbee River exhibits predictable seasonal patterns: base discharge steadily increases from December through may then decreases until late summer when, when annual lows typically ensue. The large watershed size usually ensures that few intense flood events transpire, though moderate flooding may occur at any point throughout the year.
The coastal plain aquifer is the principal aquifer in the region from which groundwater is extracted and is comprised largely of unconsolidated sediments.
The Lower Tombigbee receives large amounts of pollutant loadings via point and nonpoint sources, such as wastewater treatment, industry, forestry, urbanization, mining disposal, animal waste, and agriculture. Large amounts of impervious surface in the watershed increase the amount of pollutants delivered to the aquatic system.
Water quality is a concern in the Lower Tombigbee basin. Elevated levels of nutrients, metals (e.g., mercury), pesticides, organic toxic chemicals, and pathogens are frequently observed in the Lower Tombigbee River. Silt and sediment inputs are also high as a result of watershed activities. In addition to high nutrient concentrations leading to harmful algal blooms and decreases in oxygen, increases in organic pollutants in this region further deplete the oxygen availability, which can have large impacts on the river biology.
The Tombigbee River drainage is a hotspot of biodiversity due to long periods free of major geological change (e.g., lack of glaciation) and is among the most critical watersheds for biodiversity conservation in the country. Mettee et al. (1987) documented 121 fish species in the Tombigbee drainage. The NEON Aquatic site is located in the Lower Tombigbee River, which has been recognized by the Nature Conservancy as having 5 at-risk mussel and fish species.
The Alabama sturgeon (
Scaphirhynchus suttkusi) has been extirpated from the Lower Tombigee and is listed as historically endangered. Currently, Alabama sturgeon can only be found in the lower reaches of the Alabama River, however historically supported populations in the Tombigbee River.
Vegetation along the river corridor is largely soft woods such as pines.