Advanced Placement Environmental Science La Canada High School Dr. E

Slides:



Advertisements
Similar presentations
Water Resources Section #1: Chapter 11.
Advertisements

Water. Water distribution Water covers ¾ of the earths surface Less then 1% is available for human use 99% is found in the oceans or locked away in ice.
LT 6E: Discuss the sustainability of freshwater resources
Filtration of Water in the Recharge Zone  Water travels through soil, sand/clay to the aquifer.  What if any contaminates are removed by these layers.
Water Chapter 11, Section 2: Water Use & Management
Chapter 14 Water.
California Water Issues and Wetlands
Water.
Much of the world’s fresh water is unavailable to us because: 1.It is in deep and inaccessible aquifers 2.It exists in the form of water vapor 3.It is.
Ch 9 – Water Resources These lectures contain copyrighted images that are provided in the teacher materials for Friedland/Relyea Environmental Science.
Water Supply and Water Users Water one of the most fascinating compounds on earth necessary ingredient for all living organisms.
We Are Misusing Our Freshwater Earth’s surface is 71% saltwater Water is necessary for life, food, and shelter Global Health Issue – lack of water.
Water Sources and Pollution. Where does our water come from? It comes from 2 sources: 1.Surface water: above ground in lakes and rivers. –Most large cities.
Chapter 14 Water: A Limited Resource. Overview of Chapter 14 o Importance of Water Hydrologic Cycle Hydrologic Cycle o Water Use and Resource Problems.
CHAPTER 2.1 – WATER SUPPLY AND DEMAND. I. HOW PEOPLE USE WATER  People use water for household purposes, industry, transportation, agriculture, and recreation.
Chapter 13 Water: A Limited Resource. Overview of Chapter 13 o Importance of Water Hydrologic Cycle Hydrologic Cycle o Water Use and Resource Problems.
Water Chapters 15 Living in the Environment, 14th Edition, Miller
California’s Water Resources. California has many resources, none more important than water. The main sources of California’s freshwater supply are precipitation,
13A.2 – California’s Water Resources
Water Resources G. Tyler Miller’s Living in the Environment 13 th Edition Chapter 14 G. Tyler Miller’s Living in the Environment 13 th Edition Chapter.
Where is fresh water found? What are some California water sources?
APES Chapter 14 Water Resources. Water’s Unique Properties  Hydrogenbonding  Hydrogen bonding  Liquid over wide temperature range  Changes temperature.
13 Water. Overview of Chapter 13  Importance of Water  Water Use and Resource Problems  Water Problems in US and Canada  Global Water Problems  Water.
Chapter 9: Water Resources. Flooding- both natural and human induced. Modern floods are highly destructive because humans have: −Removed water-absorbing.
Water Resources Chapter 9. Water, water, everywhere… Most (97%) of Earth’s water is saltwater Of the 3% that is freshwater,
Water Chapter 11. Water Resources  Two types of water  Fresh (3%)  77% in icecaps and glaciers  22% ground water  1% other  Salt (97%)  Two types.
Water Resources All waterFresh water Readily accessible fresh water Oceans and saline lakes 97.4% Fresh water 2.6% Groundwater 0.592% Ice caps and glaciers.
Chapter 21 Water Supply, Use and Management. Water is Unique High heat capacity (climate) Universal solvent (dissolves compounds) High surface tension.
Chapter 7.3 (cont.) surface water Glen Canyon Dam was completed in 1963 designed to generate hydropower and create a reservoir to supply water to Arizona,
Water: A Limited Resource
SUPPLY, RENEWAL, AND USE WATER RESOURCES. HOW MUCH IS AVAILABLE? 97.4% is salt water 2.6% is fresh water Locked in ice caps and glaciers Polluted Salty.
Water Chapter : Water Resources Water is essential to life on Earth. Humans can live for more than month without food, but we can live for only.
1 Water Use and Management. 2 Water as a Resource  Covers 71% of earth’s surface  Important properties –Polar –Moves easily –Changes temperature slowly.
Water Resources “It is not until the well runs dry, that we know the worth of water.” Benjamin Franklin.
Freshwater Resources… Going…. 71% of Earth’s surface –97% saltwater –3% freshwater 2.6% ice caps and glaciers Only 0.014% of Earth’s total water supply.
Water Resources and Water Pollution
Assessment Statements – Describe and evaluate the sustainability of freshwater resource usage with reference to a case study.
Chapter 9. Water as a Resource
Chapter 13 Water Resources. Key H 2 0 Characteristics Water is the prime constituent of all living organisms. Water is the prime constituent of all living.
Global River Basin Usage How humans use water1.
WATER USE & DISTRIBUTION Chapter 11 Environmental Science.
Ch. 13 Water Resources Our liquid planet glows like a soft blue sapphire in the hard edged darkness of space. There is nothing else like it in the solar.
15.4 Human Influences on the Hydrologic Cycle Runoff and the infiltration rate are greatly influenced by human activity. A major concern in many urban.
Unit 8 Lesson 2 Human Impact on Water Copyright © Houghton Mifflin Harcourt Publishing Company.
Water Chapters 13 and 20 Living in the Environment, 11 th Edition, Miller Advanced Placement Environmental Science La Canada High School Dr. E.
Chapter 14 Water: A Limited Resource. Overview of Chapter 14  Importance of Water  Water Use and Resource Problems  Water Problems in US and Canada.
Freshwater Resources and Water Pollution
August 2008 Water Supply and Water Users Modified by Georgia Agricultural Education Curriculum Office June, 2002.
Water Chapter 11. Water Resources Section 11.1 Water is essential to life on Earth. Humans can live for more than month without food, but we can live.
California’s Water Water Law California’s Water Projects –Los Angeles Aqueduct –Hetch-Hetchy –Salton Sea –Colorado Aqueduct –Central Valley Project.
Water Supply and Water Users Water one of the most fascinating compounds on earth necessary ingredient for all living organisms.
Chapter 13 Water: A Limited Resource
Chapter 14 Water: A Limited Resource
Unit 4 Lesson 1 Human Impact on Water
Water Supply and Water Users
Water Resources Objective: I will discuss the sustainability of freshwater resources and identify pros and cons of possible solutions.
Unit 4 Lesson 1 Human Impact on Water
Water Use and Managment
Water Pollution.
Water Unit Living in the Environment, 11th Edition, Miller
Unit 4.4: Water Resources What causes water shortages?
Water.
Living in the Environment
Water Use and Management
Water Resources.
Living in the Environment
Water Resources Q: What water can we use?
Water Use.
Water Resources Chapter 9.
Water Resources CHAPTER 15
Presentation transcript:

Advanced Placement Environmental Science La Canada High School Dr. E Water Chapters 13 and 20 Living in the Environment, 11th Edition, Miller Advanced Placement Environmental Science La Canada High School Dr. E

Key H20 Characteristics Water is the prime constituent of all living organisms. Water moves easily-from one physical state to another, and from one place to another. Water slowly absorbs and releases large quantities of energy. Water is a superior solvent. Michael D. Lee Ph.D. Geography and Environmental Studies (Source: Wright & Nebel 2002)

Importance of Water Properties Running water can quickly erode topsoil rendering farmland infertile and streams contaminated. Lack of access to clean water supplies can quickly lead to dehydration and death. Chemical spills, excess nutrients & acids dissolved in H20 can lead to massive die offs. Michael D. Lee Ph.D. Geography and Environmental Studies

Water Water Pollution Supply, Renewal and Use Too little Water Dams and Reservoirs Transferring water Groundwater and Saltwater Efficiency Too Much Water Water Pollution

Available Water Total = 326 million cubic miles                                                                                                                                                                                                                                           Available Water Total = 326 million cubic miles 97% of Earth’s water is in oceans 2.997% is locked up in ice caps and glaciers 0.003% is easily accessible Soil moisture Groundwater Water vapor Lakes Streams

Water Supply & Use http://ga.water.usgs.gov/edu/waterdistribution.html

Water Cycle www.athensclarkecounty.com/~stormwater/ SW%20Management.htm

Hydrologic Cycle Powered by solar energy and gravity Evaporation and precipitation Continuous recycling of water Runoff Infiltration Evaporation Temporary storage as snow and ice Temporary storage in lakes Temporary storage in plants (transpiration) and animals Chemical reactions with rocks and minerals Volcanism also causes melting of snow caps and mudflows as melted water mixes with ash Source of additional water? volcanism (steam)

Surface Water Surface runoff flows into streams, lakes, wetlands and reservoirs A watershed or drainage basin Region that drains into a streams, lakes, wetlands or reservoirs www.canaanvi.org/assistance/ watershed.asp

Groundwater As precipitation infiltrates and percolates through voids in soil and rock Pores, fractures, crevices, etc. Shallow rock has little moisture Zone of saturation is at a depth were ground is filled with water Top of this zone is water table Falls in dry weather Rises in wet weather

HOW RIVERS WORK: the role of groundwater www.elmhurst.edu/.../chm110/ outlines/groundwater.html

Aquifers Porous, water-saturated layers of sand, gravel or bedrock through which groundwater flows Area of land that supplies water to aquifer is called the recharge area Natural recharge is when water percolates downward, but sometimes lateral recharge occurs

Groundwater Movement Groundwater moves from recharge area through an aquifer and out a discharge area well, spring, lake, geyser, artesian well, steam, ocean Normally moves downhill at only a meter per year Some aquifers get little recharge and were formed thousands of years ago Removal from these nonrenewable resources is called water mining

Use of Fresh Water United States China 41% agriculture 87% agriculture 38% power plant cooling 11% industry 10% public China 87% agriculture 7% industry 6% public

Water Use Globally People and Planet 70 per cent of all water withdrawn for human use on an annual basis is soaked up by agriculture (mostly in the form of irrigation) Industry accounts for 23 per cent Domestic use (household, drinking water, sanitation) accounts for about 7 per cent

Water Use People and Planet The average person needs a minimum of five litres (1.3 gallons) of water per day to survive in a moderate climate at an average activity level, according to UN figures. The minimum amount of water needed for drinking and cooking, bathing and sanitation is 50 litres (13 gallons).

Water Use - (minimum 13 gallons) People and Planet The average person in the United States uses between 250 to 300 litres of water (65-78 gallons) per day for drinking, cooking bathing, and watering their yard. The average person in the Netherlands uses 104 litres per day (27 gallons). The average person in the African nation of Gambia uses 4.5 litres per day (1.2 gallons of water).

Water Use - United States In 1990, about 408,000 million gallons (Mgal/d) of water were used each day Of that, about 339,000 Mgal/d was fresh water and about 69,400 Mgal/d was saline water California used the most water, about 46,800 Mgal/d, with most of that going towards irrigation The state with the second-highest water use was Texas, with about 25,200 Mgal/d, mostly for use in the power-production industries and for irrigation

1 Mgal/d = 1.547 cubic feet per second Some conversions: 1 Mgal/d = 1.547 cubic feet per second 1 Mgal/d = 0.6944 thousand gallons per minute 1 Mgal/d = 1,121 thousand acre-feet per year 1 million gallons = 3.07 acre feet http://ga.water.usgs.gov/edu/wateruse.html

Water Water Pollution Too little Water Supply, Renewal and Use Dams and Reservoirs Transferring water Groundwater and Saltwater Efficiency Too Much Water Water Pollution

Too Little Water Causes Dry climate Drought - a period in which precipitation is much lower and evaporation is much higher Desiccation - drying of soil because of such activities as deforestation and overgrazing Water stress - low per capita availability of water caused by overpopulation

Precipitation Varies Greatly US cities vary in their precipitation from an average of less than 8 to 60 inches a year. Globally, the extreme is even greater – averages of less than 1 inch to more than 70 inches per year. However, this masks variations between years. Some locations may get ten times more, or less than 1/10 of their annual average from year to year. Meeting demands for water when precipitation is so highly varied creates many challenges.

whyfiles.org/131fresh_water/ 2.html www.geocities.com/seafloormapping2/ atmos.htm whyfiles.org/131fresh_water/ 2.html

Global Precipitation Patterns Wright and Nebel, 2002. Michael D. Lee Ph.D. Geography and Environmental Studies

http://www.peopleandplanet.net/graphs/Freshwateravailability.jpg

In most areas of Nevada and California, potential transpiration and evaporation is in excess of precipitation, which causes a net moisture deficit

Drought may spark food price hike Tuesday, November 12, 2002 SYDNEY, Australia -- All but one percent of Australia's most populous state, New South Wales, has been bit by the country's worst drought in a century, with retailers warning that if rain does not fall soon, the country will likely face massive food price hikes.

Water Water Pollution Dams and Reservoirs and Transferring water Supply, Renewal and Use Too little Water Dams and Reservoirs and Transferring water Groundwater and Saltwater Efficiency Too Much Water Water Pollution

Water and Civilization Many anthropologists and historians believe the need to manage water played a major role in the development of early systems of government. In Mesopotamia, the Fertile Crescent where the Tigris and Euphrates Rivers come together, water allowed the rise of irrigation-based agriculture, but this required coordination and rules to permit equitable access to water downstream. Proto-laws and governments were thus developed some 4,400 years BP Ancient communities that prospered were those that generally well managed their water supplies. Michael D. Lee Ph.D. Geography and Environmental Studies

Examples of Water Management Many civilizations built impressive water management systems – to bring water to places where people wanted to be or where crops could be grown, but where it was naturally insufficient. Egyptians built dykes, canals and water lifts to extend agricultural limits. Middle East and North African nomads built qanats (underground chain wells). Nabateans built runoff harvesting systems – cisterns and flood terraces. Incas built canals to catch snowmelt from the Andes to the coastal desert, and terraces to flood for farming. Romans built municipal aqueducts and sewers to serve burgeoning settlements. For a good, fun site on water history go here. Michael D. Lee Ph.D. Geography and Environmental Studies

Egyptians perfected the shadouf to draw water from canals and the river to the adjacent bank and into ditches. Michael D. Lee Ph.D. Geography and Environmental Studies Nomadic herders and, later, sedentary civilizations developed chains of wells – qanats, karez, foggaras, falaj – to route water across miles of desert from distant aquifers.

Water for Power In addition to its uses for municipal purposes (drinking, sanitation, etc.) and for farming, moving water also has tremendous power to do work. This too has been harnessed for millennia – first to lift water out of the river itself, then to grind grain and turn gears for machinery like looms, and then for electricity. Water wheels have been in use for more than 2,000 years and were thought to have been a major factor in the advancement of European societies in the middle ages, as labor was freed for other purposes than farming. Following the discovery of electricity and the pioneering of electric light by Edison, in the 1880s hydropower systems were built to generate electricity to send through transmission lines to homes and businesses. Michael D. Lee Ph.D. Geography and Environmental Studies

Example of noria – water driven wheels lifting water into irrigation ditches or elevated aqueducts (This is in Vietnam) Slaters Mill in Rhode Island, one of the earliest American water powered industrial systems. Artists impression of the Three Gorges Project, Yangtze River, China – world’s biggest hydropower project 19 m kW. Michael D. Lee Ph.D. Geography and Environmental Studies

Increasing Water Supplies Build dams and reservoirs to store runoff Bring in surface water from another area Withdraw groundwater Convert salt water to fresh water (desalination) Improve the efficiency of water use

Chinese Dam Fish Bypass System Earthen Dam Aswan Dam, Egypt Hoover Dam www.wvic.com/res-main.htm

Large Dams - Pros Collect and store water from rain and snow Produce electricity Irrigate land below the dam Control flooding Provide water to cities, towns and rural areas Provide recreational activities such as swimming, boating, fishing

Large Dams - Cons Enormous loss of water due to evaporation Mass of water can cause earthquakes Flooded land destroys forests or cropland and displaces people Danger of Dam collapse Downstream areas deprived of nutrient-rich soil, which will eventually clog the reservoir Migration and spawning of fish disrupted Expensive to build

isis.csuhayward.edu/alss/geography/ mlee/geog4350/4350c6f01.ppt Case Study: California CSU Hayward Dept. Geography and Environmental Studies GEOG 4350 Fall 2001 Class 6 isis.csuhayward.edu/alss/geography/ mlee/geog4350/4350c6f01.ppt

Most of the land in Nevada and southern California is desert shrubland, because these areas receive little precipitation. By contrast, wetter areas of central and northern California are forested where mountainous and developed as farmland and urban areas are flatter

California’s Water Water Law California’s Water Projects Los Angeles Aqueduct Hetch-Hetchy Salton Sea Colorado Aqueduct Central Valley Project

Water Law Riparian Rights (Sharing) from English Common Law applies to surface waters owner of waterfront land to use amounts correlated with other riparian owners. Works well in areas with water surplus Prior Appropriation (1st come, first served) from Spanish law no preference given to those adjoining water course water rights based on use; earliest has rights use protected as long as it is continuous and “reasonable”

Water Law Correlative Rights The California Doctrine applies to ground water about 40% of all California water (not a sustainable withdraw) Overlying landowners entitled to “reasonable” use. Rights are correlated with other landowners overlying the aquifer The California Doctrine 1928 amendment to California Constitution “Most reasonable beneficial use” Blend of riparian and appropriation rights Problem: California water geography is unbalanced. Plenty of water in the north. Most people in the south.

California Water Code Highest priority for domestic use Second priority goes to irrigation Applications by municipalities for use of water by residents given priority over most other uses. Water Board determines allocation to serve public interest. Board must work within state water plans. Owens Valley issue highlights how contentious this process can be.

Los Angeles Aqueduct (DWP) Eastern Sierra Started in 1908 by William Mulholland appropriated water feeding Owens Valley taps surface flow from Eastern Sierra south 250 miles, cost $25,000,000 and took five years pipe and flume, tunnel, and trench gravity feed, no pumping generates hydroelectric power L.A. purchased riparian land, used appropriation rights to get away with this. Ranchers in Owens Valley fought back with dynamite and guns - California’s only range war.

LA Aqueduct is

Mono Lake In 1941, L.A. DWP started diverting Mono Basin streams to add to L.A. Aqueduct. Mono Lake’s volume halved while salinity doubled. The simple ecosystem began to fail and threatened migrating birds and nesting gulls. The state and courts now mandate raising the level of the lake 17 feet. It will take about 20 years.

Hetch Hetchy: San Francisco Water Hetch Hetchy Valley, in Yosemite National Park, damned. Completed in 1931. 175 mile aqueduct and O’Shawnasy Dam, powerhouse, provide cheap power to the city of San Francisco. 95 mile Mokelumne aqueduct, starts at Pardee Dam and reservoir. Together they provide about 1/3 of Bay Area water. Controversy helped to strengthen John Muir’s Sierra Club.

The Salton Sea Man-made by accident in 1905. Irrigation in Imperial Valley had flooded an ancient overflow channel of the Colorado River. Unusually heavy spring runoff and lack of control gates caused a two-year flood into the Salton Sink. The Southern Pacific Railroad had to move its tracks five times that season to higher ground. Eventually the S.P.R.R. took control and put the river back but by then the Salton Sea was created. Hoover Dam now controls Colorado and prevents delivery of sediment to Yuma and the delta. www.westernlaw.org/fischer/ 7_6text.html

Colorado River Aqueduct Established 1928 to bring water to L.A. and rest of Southern California First delivery in 1940; serves 15 million people Lawsuit from Arizona (1953) finally began to be implemented in 1985 - amount will decrease and this amount will be replaced by State Water Project water. Five pumping stations Diversions for agriculture

The State Water Project: The California Aqueduct Constructed beginning in the 1960s. About 1/2 for irrigation, about 1/2 for domestic use. Domestic use supply helps offset that lost to Arizona in 1985 court case. Includes the huge Oroville Dam on Feather River in Sierra foothills. Pumps at Tracy lift water, then it flows by gravity to the Tehachapi Mountains.

California Aqueduct

Dams and Global River Degradation Shasta Dam, CA Aswan Dam, Egypt Lake Nasser

The Geography of Large Dams Over 39,000 large dams by 1986

World Reservoir Inundation Area submerged size California

Upstream of Dams - Negative Impact Environment Loss of terrestrial/riparian habitat and species Creation of artificial lacustrine (lakes) system exotic species introductions Reservoir/storage for contaminants Cultural / social Loss of cultural resources Displacement of families (villages, regions) Water quality hazard Economic Shift in land use / economy Water loss via evaporation Water loss via seepage Aesthetic landscape inundated

Upstream Impact of Dams Built 1956-1966. Aesthetics: Glen Canyon, Colorado River

Downstream Impacts of Dams Altered hydrology - no seasonality Altered water quality/character Modify nutrient cycling Reduce sediment supply Channel adjustments Habitat modification Species impacts River fragmentation

The ‘Dam’ Balance Some dam removal (small dams) or operational changes (larger dams) Bruce Babbit (Secretary of the Interior) oversaw the creative destruction of two California dams in 2000 Saelzer Dam on Clear Creek near Redding, for Salmon Matilija Dam in Southern California Dams continue to be built until good sites are gone, or it is not economic to build them. Global numbers? We do not know

Three Gorges Dam World's largest hydroelectric dam, Three Gorges, Yangtze River. 1.2 - 1.9 million people will be displaced. The entire project is to be completed in 2009.

Summary of California Water Systems Very complicated. Politically controversial - Owens Valley, Dams, Habitat changes, reduced flushing of SF Bay Delta. California has the most advanced and expensive water delivery system in the world. Most of the water (about 80%) is used by agriculture; essential to California’s huge farm industry. Michael D. Lee Ph.D. Geography and Environmental Studies

New Alaskan Pipeline A coastal, subsea pipeline has been proposed 2000 mile long from one or more rivers in Alaska to Shasta lake where it would join present system $110 billion estimate in 1990 no leakage or loss due to evaporation from 14-foot diameter pipeline 4 million acre-feet of water transported per year 36 million acre-feet of water needed per year in 2010

Water Water Pollution Groundwater and Saltwater Supply, Renewal and Use Too little Water Dams and Reservoirs Transferring water Groundwater and Saltwater Efficiency Too Much Water Water Pollution

Tapping Groundwater About half of the drinking water in the United States is pumped from aquifers Roughly 40% of the water in streams/river is from groundwater The number one removal of water from aquifers is for irrigation for farming

Groundwater Problems Aquifer depletion Aquifer subsidence more water is removed than is naturally refreshed Aquifer subsidence land sinks due to withdrawal of groundwater (Mexico City) Intrusion of salt water into aquifers Contamination from multiple sources

Groundwater Depletion Aquifer Depletion 95% of water removed from Ogallala Aquifer is for irrigation and the removal rate is greater than the refreshing rate Saudi Arabia, China, northern Africa, southern Europe, Middle East, Thailand, India www.npwd.org/Ogallala.htm

Aquifer Subsidence Well casing projecting from the ground (40 years) Mexico City’s aquifer has shrunk enough that land has dropped up to 7.5 m http://www.geotimes.org/july01/sinking_titanic_city.html http://www.science.uwaterloo.ca/earth/waton/mexfig2.html

Salt Water Intrusion “One-third of the water supply for coastal areas of Greater Los Angeles comes from local ground-water sources. Saltwater has penetrated a part of the supply, and a significant part of the remaining supply is at risk.” U.S. Geological Survey Fact Sheet 030–02

Desalination Removal of salts from ocean water distillation first land-based desalination plant was established in 1928 in the Netherlands www.oas.org/usde/publications/ Unit/oea59e/ch21.htm

Desalination Removal of salts from ocean water reverse osmosis using high pressure The Santa Barbara facility began operation in March 1992 http://www.tampabaywater.org/MWP/MWP_Projects/Desal/Desal.htm http://urila.tripod.com/

Water Water Pollution Efficiency Supply, Renewal and Use Too little Water Dams and Reservoirs Transferring water Groundwater and Saltwater Efficiency Too Much Water Water Pollution

Reducing Water Waste Up 70% of water is lost through evaporation & leaks repair leaky pipes/canals recycling use of gray water (i.e. from shower) for irrigation etc. water conservation efficient toilets, faucets, & shower heads irrigation efficiency (only 40% reaches crops) drip irrigation, central–pivot, computer monitoring

Types of Benefits Possible benefits of canal replacement with pipeline: reduction in seepage losses improvement of head and on-farm water delivery better operation of distribution network reduction in maintenance costs

Direct Potable Water Reuse Drinking Water Wastewater Treatment

Direct Potable Water Reuse Case Studies: Windhoek, Namibia Denver, Colorado Health concerns Public perception

Windhoek, Namibia Population: 220,000 Severe water shortage First and only city using direct potable water reuse (Since 1968)

Windhoek, Namibia 40% of water demand returned as wastewater 2,000 m3/day of reclaimed water Basic public acceptance No significant epidemiological trends Data consistent with WHO health trends

Denver, Colorado Direct Potable Reuse demonstration project (1985-1992) Drinking water influent is secondary treated wastewater Several barriers of treatment Standard Drinking Water Treatment Carbon Adsorption Ultraviolet Irradiation Reverse Osmosis/Ultrafiltration Air Stripping Disinfection (ozonation and chlorination)

Denver, Colorado High water quality (meets all EPA standards) No adverse health effects Tested on animals Carcinogenic and reproductive tests Public awareness and education programs Majority of acceptance if sufficient need exists

Specific Uses for Recycled Water Toilet flushing Subsurface drip irrigation Safer Non-aerosolizing of water and pathogens More prone to clogging Requires more maintenance More efficient Less evaporative water loss Feeds roots of plants/grass directly

Water Water Pollution Too Much Water Supply, Renewal and Use Too little Water Dams and Reservoirs Transferring water Groundwater and Saltwater Efficiency Too Much Water Water Pollution

Too Much Water: Floods Natural flooding is caused primarily by heavy rain or rapid melting snow. This causes water in a stream to overflow it normal channel & flood the adjacent area, called a floodplain. Floodplains, which include highly productive wetlands, help to: Provide natural flood & erosion control Maintain high water quality Recharge groundwater When the floodwater recede, deposits of silt are left behind, creating a nutrient-rich soil.

Too Much Water: Floods People have been settling in floodplains for several reasons: Fertile soil Sufficient water for irrigation Flat land suitable for agriculture Use of nearby rivers for transportations However, each year floods (“natural disasters”) kill thousands of people & cause tens of billons of dollar in property damage. Human activities have contributed to the sharp rice in flood frequencies which dramatically increased flood deaths & damages.

Flooding Human activities that increase flooding: removing vegetation logging overgrazing forest fires mining destruction of wetlands building on floodplains urbanization © Brooks/Cole Publishing Company / ITP

Too Much Water: Floods Natural phenomena Aggravated by human activities Renew and replenish Floodplain Levee Flood wall Dam Reservoir