1. Part 1: Water • Water is stored in “reservoirs” • Oceans • Lakes • Rivers • Atmosphere • biosphere

3. Cover 71% of Earth’s surface Oceans

4. SEA SEA LAND LAND + 336 Runoff from land + 398 Precipitation over sea + 434 Evaporation + 434 Evaporation – 398 Precipitation + 436 Excess to land via precipitation + 107 Precipitation – 371 Evaporation + 436 Runoff to ocean + 107 Precipitation – 336 Runoff to ocean + 471 Evaporation Precipitation 107 Evaporation 71 Evaporation 434 Precipitation 398 Surface runoff Infiltration Runoff 36 Groundwater table Groundwater flow

5. Porosity: The percentage of the volume of a rock occupied by open space between grains

6. Permeability: The capacity of a rock to allow fluids to flow through it

8. Subsurface Distribution of Water

9. Ogallala Aquifer Sand and gravel from 6 Ma-2 Ma Provides about 6 billion cubic meters water/year from 170,000 wells Irrigates 5.1 million acres of land and has water for > 1 million people Recharge area is local. Will go dry in early 21st century

10. Ogallala Aquifer

11. Central Plains Minimal rainfall “Dustbowl” in the 30’s Central pivot irrigation Extraction is 100 times greater than recharge rate.

19. Las Cruces Water Use • Where does our water come from? • Where does the water go after use? • Domestic • Agriculture

20. Las Cruces Water Use • All water comes from groundwater • In 10?-15 years: surface water (Rio Grande) • Treatment = $$$ • Farms vs. homes

21. Las Cruces Water Use • Your water bill: • 1st 5000 gallons per month are cheap • Each interval of 10,000 gallons get more expensive • El Paso/Juarez have a more critical problem • There are no limits on development (YET)

22. TUCSON WATER: CENTRAL ARIZONA PROJECT Mineral content is 325 ppm, will rise to 650 ppm by 2020. Treatment plant? Will reduce to 450 ppm Cost: $340 million OR just pipe it into your home and see what happens

23. Las Cruces WATER: Low levels of arsenic Uranium concentrations: Maximum contaminant level: 30 ppb Highest detected levels: 132 ppb “Exposure may result in toxic effects to the kidney.” “Some increase risk of cancer”

24. EROSION BY GROUNDWATER

32. Water soaks into the soil and filters down. Hot springs occur where heated groundwater is discharged at the surface. Hot springs Sinking cold water Geyser Steam and boiling water are released under pressure, resulting in intermittent eruptions. Permeable volcanic rock Fault zone Impermeable volcanic rock As the water approaches the magma, it heats up and becomes less dense. Rising hot water Magma Zone of intense heat