Instream flow requirements are the amount of flows or releases necessary to maintain the health and integrity of estuarine ecosystems (TCEQ 2009). Instream flow requirements are generally set to the minimum flows necessary, but they can also include maximum flow limits for hydropower dams, seasonal releases for fish spawning, or weekend releases for recreational purposes (TCEQ 2009). There are a variety of methods used to set flow standards.
In Texas, Senate Bill 3 passed in 2007, which calls on scientists, stakeholders, and officials to address two issues: how much water is needed to keep the state’s estuarine systems healthy and how the state can protect that water (TCEQ 2009).