Rincon Bayou long-term sampling of water and sediment quality 28-October-1994 to 23-April-2019

The Nueces River is the primary source of freshwater inflow to Corpus Christi Bay and virtually the only source of freshwater inflow in the Nueces Delta. Construction of two dams in the Nueces Basin reduced environmental flow and increased salt concentrations in the soil and water have compromised the function of the Nueces Delta Marsh as a viable component of the estuarine ecosystem. This dataset is sediment and water quality monitoring of two major hydrological restoration projects. In 1993, the U.S. Bureau of Reclamation began a 5-yr diversion project to increase the opportunity for freshwater flow into the delta by excavating two overflow channels, thus lowering the minimum flooding threshold for the upper delta to promote more frequent diversions of freshwater from the Nueces River to the marsh. In 2009, a pipeline was built to enhance flows and restore hydrological connections between the river and marsh. Pumping from the Calallen Pool into Rincon Bayou occurs only when there is also natural inflow because that is the only time when passthrough is required. Nutrients are high when salinity is low. The diversity of macroinfauna and meiofauna is low. There are very high fluctuations of abundance and biomass related to fluctuations in inflow. The low diversity and population fluctuations indicate the ecosystem is disturbed.