1. Capay Diversion Dam Modernizing for Sustained Irrigation Demand George V. Sabol, PhD, PE Principal, Stantec Consulting Tim O’Halloran, PE General Manager, Yolo County Flood Control & Water Conservation District Michael Horgan, PE Engineer, Yolo County Flood Control & Water Conservation District 2009 SAME California Water Conference Sacramento, California October 27-28, 2009

3. Davis, CA Woodland, CA

4. Photo from Helicopter 470-foot long Capay Dam Grade Control Structure Winters Canal West Adams Canal Cache Creek Apron Replacement

5. Capay Dam – Bladder Deflated, Winter Low-Flow

6. 2005 Inspection of Dam

7. Reproduction of 1914 design drawing with 2003 observations in red.

8. 2003 Partial Failure of Apron

9. Local Scour at Toe of Apron & Streamed Degradation of Cache Creek

10. Sediment Deposition above Dam

11. Sediment Abrasion of Concrete Since 1993

12. Sediment Damage to Concrete Piers Since 1993

13. Placing Drill Rig on Apron in 2005

14. Non-Destructive Testing of Concrete in 2005

15. Cracking & Distress of Concrete Abutment Wall

20. Periodic Inspections are Necessary for Dams & Levees. Modern Testing Methods are Cost Effective in Assessing Structural Integrity of Dams. Conclusions