Focused Flows to Maintain Natural Nursery Habitats
Cover photo: Llano River with fisherman. ©2018 Ray Uherek.


Environmental flow
Freshwater inflow
Focused flows
Nursery habitats

How to Cite

“Focused Flows to Maintain Natural Nursery Habitats”. 2021. Texas Water Journal 12 (1): 129-39.


Regulatory standards for environmental flows to estuaries are not common, but they are required in Texas. This has led to adoption of complex freshwater inflow regimes that reflect seasonal and yearly fluctuations that vary geographically throughout the state. The flow regimes are based on dilution of saline water with fresh water in whole systems. Because the estuaries are large lagoons, large volumes of fresh water are required to meet standards. However, this volume of water is not available during dry periods. We present a new concept, focused flows, for lower flow volumes that would maintain the ecological health of the upper reaches of estuaries during droughts. The concept is based on maintaining ecological integrity of nursery habitats, which is an important ecological function of estuaries. These focused flows would protect nursery habitats during droughts and allow estuaries to recover more quickly when the hydrology returns to average or higher flow periods. This approach could be applied globally where increasing water infrastructure and deficits are a concern or increasing aridity due to climate change is reducing river flows to coasts.



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Copyright (c) 2021 Paul A. Montagna, Larry McKinney, David Yoskowitz