Water development projects can reduce the capacity of the land to deliver freshwater to estuaries and change timing and frequency of freshwater pulses, in turn affect estuarine organisms adapted to historic saline conditions.
Salinity is an important indicator of estuarine condition. Remember, when trying to determine flow standards, an indicator species can be used to determine that organism’s salinity tolerance range (Montagna et al. 2013). The biological indicator’s salinity tolerance range has the capacity translate to acceptable salinity levels within the estuary. The acceptable salinity range in the estuary could be created with freshwater inflows by determining the mixing rate, or how much freshwater is necessary to mix with the volume of saltwater within the estuary to result in the desired salinity range (TCEQ 2009).