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

Oceans Cover 71% of Earth’s surface

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

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

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

Subsurface Distribution of Water

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

Ogallala Aquifer

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

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

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

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)

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

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”

EROSION BY GROUNDWATER

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