1. 1 Turn in fire management essays (with graded outlines attached) Tuesday 4/29 Next week – (4/29) Global change – 5/1 Review for Part III unit exam (final exam) Notes 4/24

2. 2 Today’s topic: Water in the Southwest Water stats & cycling Groundwater –Subsidence Colorado River Readings for today: Required General reading: Cadillac Desert

3. 3 Water Information at UA Water Resources Research Center (WRRC) –Campbell, just south of 6th –Free Newsletters Arroyo Arizona Water Resource –Xeriscaping

4. 4 96% of Earth’s water ------- 74% of Earth’s fresh water is ------- 99% of Earth’s fresh liquid water is -------- Water water everywhere, not a drop to drink

5. 5 Units: ------------------------------ Oceans: ----------------------------- Fresh water: surface, subsurface, or evap Water Cycle

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8. Where do we get our Water? - –------ -------- –--------- ----------- –----------- (--------------) 8

9. 9 What Is An Aquifer? Aquifer - - bedrock water table aquifer

10. 10 Depth can be ------------------------------ –----------------------------------------------------- Filled in with water –---------------------------- –-------------------------------------. Basin Fill

11. 11

12. 12 1995 Annual Groundwater Budget Tucson Active Management Area Inflow= + -------------------- - Outflow = - -------------------- - Balance (OVERDRAFT) = - ---------------- Acre-foot: water 1 foot deep covering 1 acre (43,560 ft 2 ) = 325,851 gal. SRC Pool: ~2 acre-feet

13. 13 Consequences Of Overdraft 1. - 2. - 3. - 4. - 5. -

14. 14 From over pumping of groundwater Over 15 feet in ~40 years Everything sinks (even trees) Can be general, or with fissures. Subsidence

15. 15 Subsidence Fissuring and Infrastructure -

16. 16 Extent of Subsidence Areas with 1600 ft. of sediments (gray) Areas with serious subsidence (red) –Agriculture areas –Municipalities Conclusion: Best not to deplete groundwater

17. 17

18. 18 How Much Water Left Under Tucson? So, --------------------- left,

19. 19 Well Hydrograph Pima & Swan

20. 20 Consequences Of Overdraft 1. - 2. - 3. - 4. - 5. -

21. 21 Colorado River Watershed Seems big, but actually not (m 3 /sec): –Colorado: --- –Columbia: ------ (40x) –Miss.: -------- (104x) –Amazon: ---------- (1000x) Surface Water Source: http://www.rev.net/~aloe/river/

22. 22 Lee’s Ferry flow: 13.5 maf/yr How many people would that provide for?

23. 23 Whither the Rainfall? Assume avg ppt of 12 in./yr Assume half of CRB above Lee’s ferry CRB receives over 5x more rainfall than it drains Where does 80% of rainfall go?

24. 24 Colorado River Compact, 1922 AZ: W.S. Norviel (2 nd from left) 4 th from left? (hint: It’s not Haury)

25. 25 WY, CO, UT, NM – Upper Basin AZ, NV, CA – Lower Basin –AZ: ------------ of basin, ---------- of water –Who was left out? 7.5 maf for each basin per year –75 maf to Lower Basin per decade Extra 1 maf for Lower Basin, just to be nice. Colorado River Compact

26. 26 Flow was assumed to 16.4 maf per year Past 300 years: –Average: ------------------- –Range: ---------------------- How do we know this? Reality Check

27. 27 Navajo Tribe –All within basin –Might claim > 5 maf –Can’t use it, but might sell it Mexico –1944 treaty: 1.5 maf –No flow to delta: water, silt, nutrients Other Parties

28. 28 Colorado River to Tucson? Carl Hayden legacy Begun in 1960s 300+ miles of canals Uphill –Havasu: 482 ft. –Enormous pumps Magnificent project $3.6 billion

29. 29 CAP Pump: –------------- gal./sec. –------------ up Hohokam would be so proud!!

30. 30 --- ------- ------------- –CAP water unpopular to drink “------------------ ------------- –CAP expensive to farm Only 1 profitable crop? –Maybe 2?? Arizona and CAP Water

31. 31 Importing Salts to Southern Arizona CAP water has 580 mg/L salts Where goeth the salts?

32. 32 Groundwater Pumping ---- -----

33. 33 Fix your faucets all you want … People replace cotton and lettuce, water use  Statewide Use: It’s agriculture

34. 34 Water Summary ------------ -------------- ------ –-------- SW big rivers –-------------- --------------