Assimilative Capacity of Lake Livingston

Science Center Objects

The nutrient and sediment data collected by this study provides insight into assimilative capacity of reservoirs and impacts to inflows for coastal Texas.

The 2012 Texas State Water Plan calls for 26 new reservoirs to increase water supplies by 1,500,000 acre-feet/year in 2060 for meeting the States future water needs. Reservoirs are costly to build, and have ecologic and hydrologic impacts downstream by affecting freshwater inflow and the supply of sediment and nutrients to Texas coastal ecosystems.

More than half of inflows into Galveston Bay come from the Trinity River. The USGS, in cooperation with the Texas Water Development Board, has evaluated the variability of nutrient and sediment concentrations entering Texas bays and estuaries during a variety of flow conditions (including a number of high flow events on the Trinity River).  Initial results  indicate that releases in the Lake Livingston reservoir may play an important role in controlling sediment and nutrient load variability to the coastal ecosystem. The effect Lake Livingston has in sequestering sediment and nutrients is not well understood; quantifying the assimilative capacity of Lake Livingston is critical in understanding the impacts of reservoirs on the health of the Galveston Bay ecosystem.

This study measures the assimilative capacity of Lake Livingston.  Inflows into Lake Livingston and the outflows are sampled to obtain before and after numbers for nutrients and sediments. Assimilative capacity changes depending on flows; the study will obtain samples during a variety of flow conditions.

The surface water data sampled during the proposed project will be analyzed to determine the assimilative capacity of the reservoir for nutrients and sediments supply to the Galveston Bay ecosystem. This information would benefit a number of different researchers and provide insight into assimilative capacity of reservoirs and impacts to inflows for coastal Texas.