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Bays in Peril: A Natural Inflow Approach for Texas Estuaries. Norman D. Johns, PhD, National Wildlife Federation Warren Pulich, PhD, Texas State University. general.
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Bays in Peril:A Natural Inflow Approach for Texas Estuaries Norman D. Johns, PhD, National Wildlife FederationWarren Pulich, PhD, Texas State University
general “managing an ecosystem within its range of natural variability is an appropriate path to maintaining diverse, resilient, productive, and healthy systems” (Swanson et al. 1993) flows Maintain “full natural range of variation of hydrologic regimes...”measured by – timing, frequency, duration, and rate of change of key biologically significant hydro events (Richter et al. 1997) The Natural Flow Paradigm
Galveston Bay Measured Freshwater Inflows High Variability is Inherent
productivity maintenance-4 month spring/early summer freshwater inflow pulse (a.k.a. “Freshete”) 1. NWF’s Ecologically Relevant Inflow Criteria
productivity maintenance-4 month spring/early summer freshwater inflow pulse (a.k.a. “Freshete”) 1. 2. droughtanalysis – 6 consecutive months very low-inflows, between Mar. – Oct. NWF’s Ecologically Relevant Inflow Criteria
WAM = Hydrology Tool - predict inflows - differing scenarios: Natural ConditionsCurrent UseFull Water RightsLevels of reuse - monthly results
National Wildlife Federation Analysis of Estuary Inflows productivity maintenance- spring Freshete droughtanalysis - population survival
NWF’s Low Flow Assessment [ MinQsal ]
Next Steps Application to Regional Planning Process Refinement of Criteria (time window, benchmark volumes based on natural stats.) Further examine ecological relevance ofcriteria