Instream Flow Resources Project Hydrologic Foundation Committee

1. Gulf Coast Prairie Landscape Conservation Cooperative Instream Flow ResourcesProjectHydrologic FoundationCommittee Webinar Meeting #3 July 16, 2013 Presented in cooperation with

2. Meeting Objectives • Review the status of the Flow-Ecology Hypotheses and selected USGS gages for testing the hypotheses • Solicit feedback on • Approach • Periods of analyses • Metrics • Other? • Next steps for this committee

3. Flow-Ecology Hypotheses Tests Update • Fish-Gage paired data • Ecological metrics • Hydrologic metrics • Reference and Altered periods for analyses • Statistical analyses • Flow-Ecology • Hydrologic

4. F-E Hypothesis F.1.a: Altered timing of high flow pulses during Alligator gar spawning season (April-June) alters the availability of spawning habitat. Timing of high flow pulses diminishes habitat accessibility by shortening the time fish can access floodplains.

5. Locations of paired Fish-Gage data N=52

6. Determination of “Reference” and “Altered” Hydrologic Conditions for Quantification of “Degree of Alteration” * dam * Degree of Alteration = (alt – ref)/ref Fish sample dates

7. Preliminary Criteria for Selecting “Reference” and “Altered” Periods Altered period: 20 years prior to most recent fish sample date * Reference period: 1940-1960 or first 20 years of record * * Adjusting to avoid dam construction years

8. Preliminary IHA metrics for testing GCPLCC Regional Flow-Ecology Hypotheses:

9. Sources of Hydrographs for the GCPLCC Hydrologic Foundation • Gage data (not so limited?) • Statistical approaches • Hydrologic models • Multiple local models (very limited use in GCPLCC region) • Regional model (most commonly used in other areas)

10. Meeting Objectives • Review the status of the Flow-Ecology Hypotheses and selected USGS gages for testing the hypotheses • Solicit feedback on • Approach • Periods of analyses • Metrics • Other? • Next steps for this committee