1. Subsidence at Conaway Ranch, Yolo County Tad Bedegrew October 29, 2015 North Central Region Office - DIRWM Geology and Groundwater Investigations Section

2. Presentation Outline Background Information Construction Info Period of Record Recent Activity 2013 2014 2015 Future Plans Continuous recording/CDEC 2

3. Location 3 Davis Woodland West Sacramento Yolo County Sacramento County

4. Construction Information 4 80-90 140-150 240-280 535-545 620-638

5. Extended Period of Record 5

6. 2013 Water Transfer 6 20 Pumping Wells ~5,700 AF Pumped for Transfer July – September

7. 2013 Displacement 7

8. 2014 Water Transfer 8 22 Pumping Wells ~14,000 AF Pumped for Transfer May – early September

9. 2014 Displacement 9

10. 2014 Survey 10 Extensometer Survey showed ~6” of subsidence at Extensometer location

11. 2014 Survey Comparison 11

12. 2014 Extensometer Modifications 12 ~2” May 27, 2014

13. 2014 Extensometer Modifications 13 5/27/14 6/16/14 7/8/14 8/7/14 ~1” ~2” ~4”

14. 2014 Extensometer Modifications Round 2 14 ~4” August 12, 2014

15. 15 535-545 620-638 Slip Joint seized up? Subsidence occurring between 620’ and the surface? Combination of the two? Why?

16. 2015 Water Transfer 16 16 Pumping Wells ~5,400 AF Pumped for Transfer Late May - June

17. 2015 Displacement 17

18. Current Recording Equipment 18 23+ years old No longer continuous recording, must move pin manually Visiting Conaway Extensometer weekly since May 2014 due to activity

19. Future Plans 19 Installation of digital shaft encoder Continuous recording using CR1000 Data Logger Cellular Telemetry CDEC?

20. NASA JPL InSAR 20

21. Questions? 21