ELEVATION IN FEET

1. AN EVALUATION OF THE COMPATIBILITY BETWEEN NAVIGATION AND ENVIRONMENTAL RELEASES FROM THE ACF RESERVOIR SYSTEM

3. PROFILE APALACHICOLA AND CHATTAHOOCHEE RIVERS Head of Navigation ELEVATION IN FEET 1200 1000 800 600 400 200 0 BUFORD DAM (Lake Sidney Lanier) 400 200 0 Atlanta, GA WEST POINT LAKE WALTER F. GEORGE L&D GEORGE W. ANDREWS L&D JIM WOODRUFF L&D Columbus, GA APALACHICOLA RIVER CHATTAHOOCHEE RIVER A big river system with limited reservoir control MILES

4. State of the SystemMay 2011 • Compacts expired 2004 • IOP 2007 – ESA • Drought of 2007-2008 • RIOP 2008 • Magnuson decisions 2010 • 11th circuit appeal 2011 • Draft basin manuals - 2011 • On/off state negotiations • ACF Stakeholders groups

5. State of the RiverMay 2011 • Navigation dead in the water • while • Water use continues to grow despite legal uncertainty • Lack of flow targets in the mid-Chattahoochee • Angst of both lake users and oyster men

6. Frustrated ? How do we get out of this?

7. RELATIONSHIP BETWEEN FLOW AND CHANNEL AVAILABILITY

8. Outflow at Jim Woodruff varying water flow levels with and without navigation releases 25 Exceeded Median 75 Exceeded 90 Exceeded

9. HEC RASChannel Model

10. New Soundings

11. Mile 39

12. Conversion from HEC2

15. Channel Description No Dredging Reference Dredging 250,000 yards 7’ – 10,000 cfs 9’ – 14,000 cfs • 7’ – 17,000 cfs • 9’ – 21,000 cfs With about 250,000 cubic yards of dredging a 9-foot channel could be provided with 14,000 cfs flow and a 7-foot channel with 10,000 cfs flow.

16. Flow Augmentation Plan • In our re-coding of the RIOP release logic in the models we included a provision of where a release is made when the 7-day basin inflow was a specified amount (x) below the required flow to provide a navigation channel. • To evaluate augmentation levels multiple model runs were done at varying levels of augmentation and for varying navigation scenarios depending on the level of dredging needed to provide the channel.

17. How It Works 7 day basin inflow Flow for a given channel depth Levels of augmentation Threshold flow

18. RIOP The RIOP operations were designed to provide for the flow needs of federally listed species (sturgeon and mussels)

19. RIOP

20. ResSim and Stella Calibration • Flows and elevations throughout the basin

21. Sensitivity Analyses • Demands (current to 50% increase) • Augmentation Thresholds (1,000 to 10,000 cfs) • Navigation flows for different channels (9-FOOT FLOW 14,000 – 21,000 cfs) • Columbus target (active vs. inactive) Used Stella for making large number of runs required for ranges of alternatives because of its quick run-time.

22. Navigation Patterns • Navigation Season January – May • Low flow period June to November • Much lower availability • Regularity of shipping service a major concern

23. Navigation Performance Measures • Percentage availability by month • Consecutive days with a channel • Consecutive days without a channel • 7 and 9 foot channels • Dredging and without dredging

24. Availability of a 9-foot channel

25. Availability of a 7-foot channel

26. Mid – Chattahoochee Minimum Flows • Columbus • Continuous 850 • Daily 1,350 • Weekly 1,850 • Columbia • 2,000 • Woodruff • 5,000

27. Mid-Chatt. Flow • No set augmentation in the RIOP mode • Set daily target

29. Lake Lanier RIOP – No Withdrawals RIOP - + Navigation RIOP - + 50% Increase Demands

30. Just the Highlights Report to follow