Water Quantity and Quality

HYDROLOCIC CYCLE

Hydrologic cycle with humans

Global water balance Amount is finite Uneven distribution

“Usable” Water Salt water (97%) Fresh water (3%) Ice (2%) Groundwater (0.97%) “Surface” water (0.03%) Consider which of these is usable for drinking water.

What do you use water for?

Water uses - Agriculture Huge amounts of withdrawal and consumption (70% worldwide) Various irrigation systems, but consider efficiency Dams, canals, pumps

Industrial uses About 20% worldwide withdrawal Power production is primary usage here; most is non-consumptive Degradation is big problem

Domestic water use 10% of withdrawals worldwide Toilets, teeth brushing and hand washing, drinking/cooking, laundry and dishes, bathing

Usage in typical US home

Solutions Conservation and recycling Desalination Policies including pricing

US water “policies” Riparian rights: can use water as long as doesn’t interfere with others (eastern US) Appropriation rights: first in time, first in rights….buying and selling of water rights…beneficial use….western US

Watershed management System approach surface water, land use, groundwater Area of land that supplies water to a river Examples: Mississippi, Colorado, Catawba

Watershed of Mississippi River

Colorado Watershed

NC/SC line

Watershed of the Catawba River Upper Catawba Lower Catawba

Dams Benefits: power, recreation, flood control, water supplies for some cities and towns Costs: displacement of people, sediment disruption, habitat alterations, disruption of flooding needed for healthy soils

Examples of dams and levees Mississippi River Yangtze River Colorado River Catawba River

Lakes of the Catawba North Carolina James Rhodhiss Hickory Lookout Shoals Norman Mountain Island Half of Wylie South Carolina Half of Wylie Fishing Creek Wateree

Water quality relative to population along Catawba From Duke Power data

Water pollution Water pollution: departure from purity Sources: point vs. non-point sources Problems caused and possible solutions

Examples of pollution (1) Toxic chemicals Pesticides, petroleum, synthetic chemicals Pathogens and waterborne diseases Sewage is a primary source

Examples of pollution (2) Nutrients: primarily P and N Algal blooms Oxygen-demanding wastes Effects on DO and BOD

Examples of pollution (3) Sediment Thermal pollution: too hot, too cold

Examples of pollution (4) Groundwater pollution

Water treatment Drinking water What about bottled water? Wastewater treatment Primary treatment Secondary treatment Role of buffers and wetlands

Clean Water Act Has it been successful?

Examples of ocean pollution Oil Land runoff Garbage Sewage Atmospheric deposition

Some solutions Source reduction Land management: Soil conservation helps water quality Addition or preservation of wetlands Proper sewage disposal Primary vs. secondary treatment Living machines or natural systems

Preventing overfishing Consumer choices Marine reserves Fishing methods Seafood WatchSeafood Watch: (