1. Instream Flow Resources Project Hydrologic Foundation Committee Webinar Meeting #3 July 16, 2013 Presented in cooperation with Gulf Coast Prairie Landscape Conservation Cooperative

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

7. Reference period: 1940-1960 or first 20 years of record * Altered period: 20 years prior to most recent fish sample date * Preliminary Criteria for Selecting “Reference” and “Altered” Periods * 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 1.Gage data (not so limited?) 2.Statistical approaches 3.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