Environmental Science: Water Scarcity and Conservation
Understanding why water becomes scarce and how people can conserve it
Environmental Science: Water Scarcity and Conservation
Understanding why water becomes scarce and how people can conserve it
Environmental Science - Grade 6-8
- 1
Explain the difference between physical water scarcity and economic water scarcity.
Think about the difference between not having enough water and not being able to get clean water.
Physical water scarcity happens when there is not enough water in an area to meet people’s needs. Economic water scarcity happens when water exists nearby, but people do not have the money, pipes, treatment systems, or access needed to use it safely. - 2
A shower uses 2 gallons of water per minute. If a person takes a 12-minute shower, how many gallons of water are used? How many gallons would be saved by taking an 8-minute shower instead?
A 12-minute shower uses 24 gallons of water because 2 times 12 equals 24. An 8-minute shower uses 16 gallons, so the person would save 8 gallons of water. - 3
Only a small part of Earth’s water is fresh water that humans can easily use. Explain why oceans do not solve most water scarcity problems.
Consider the difference between salt water and fresh water.
Oceans do not solve most water scarcity problems because ocean water is salty and cannot be used directly for drinking, farming, or many industries. Removing salt through desalination takes energy, money, and special equipment. - 4
A town pumps groundwater from an aquifer faster than rain and snowmelt can refill it. Describe two possible effects of this overuse.
An aquifer is like an underground water storage area.
Overusing an aquifer can lower the water table, making wells run dry or requiring deeper wells. It can also cause land to sink in some places or allow salty water to move into the aquifer near coasts. - 5
A farmer switches from flood irrigation to drip irrigation. Explain how this can help conserve water.
Drip irrigation helps conserve water by sending small amounts of water directly to plant roots. Less water is lost to evaporation, runoff, and watering areas where crops are not growing. - 6
A family finds that a leaky faucet wastes 3 gallons of water each day. How many gallons are wasted in 30 days? Explain why fixing small leaks matters.
Multiply the gallons wasted each day by the number of days.
The faucet wastes 90 gallons in 30 days because 3 times 30 equals 90. Fixing small leaks matters because small daily losses add up to a large amount of wasted treated water over time. - 7
List three household actions that can reduce water use without seriously changing quality of life.
Three household actions are fixing leaks, taking shorter showers, and running dishwashers or washing machines only with full loads. These actions save water while still allowing people to meet their daily needs. - 8
A city uses water for homes, farms, parks, and factories. During a drought, leaders limit lawn watering but keep drinking water available. Explain why this is a reasonable conservation choice.
Think about which water uses are necessary for survival and public health.
This is reasonable because drinking water and basic sanitation are essential for health and safety. Lawn watering is less necessary, so limiting it can save water for more important needs during a drought. - 9
Climate change can affect water scarcity. Describe two ways a warmer climate can make water supplies less reliable.
A warmer climate can increase evaporation from soil, lakes, and reservoirs, leaving less water available. It can also change precipitation patterns, causing longer droughts in some places and heavier storms that run off quickly instead of soaking into the ground. - 10
A water bill shows these daily uses: showering 32 gallons, toilets 24 gallons, laundry 18 gallons, dishwashing 6 gallons, and leaks 10 gallons. What is the total daily water use? Which category should the family try to reduce first, and why?
Add all categories, then compare which use is largest or easiest to eliminate.
The total daily water use is 90 gallons because 32 plus 24 plus 18 plus 6 plus 10 equals 90. The family could reduce showering first because it is the largest category, or they could fix leaks first because leaks waste water without providing any benefit. - 11
Explain what is meant by a product’s water footprint. Give one example of a product that may have a large water footprint.
Think beyond the water you see and include water used during production.
A product’s water footprint is the total amount of water used to grow, make, process, and transport it. Beef, cotton clothing, and many processed foods can have large water footprints because they require water at many stages. - 12
A coastal city is considering desalination to increase its drinking water supply. Give one benefit and one drawback of desalination.
One benefit of desalination is that it can turn abundant seawater into fresh drinking water. One drawback is that it uses a lot of energy and can produce salty waste that must be handled carefully. - 13
Study this reservoir data: January 80 percent full, March 70 percent full, May 55 percent full, July 35 percent full, and September 25 percent full. Describe the trend and explain one possible reason for it.
Look at whether the percentages are increasing or decreasing from month to month.
The reservoir level is decreasing over time, dropping from 80 percent full in January to 25 percent full in September. One possible reason is drought, increased water use in warmer months, or reduced snowmelt flowing into the reservoir. - 14
A neighborhood wants to reduce outdoor water use. Choose two of these ideas and explain why they would help: planting native plants, watering at noon, collecting rainwater, replacing grass with mulch, or using sprinklers on windy days.
Choose ideas that reduce evaporation, runoff, or the need for extra watering.
Planting native plants would help because they are adapted to the local climate and often need less watering. Collecting rainwater or replacing grass with mulch would also help because they reduce the need for treated tap water and slow evaporation from soil. - 15
Respond to this claim: Earth has plenty of water, so humans do not need to worry about water scarcity.
The claim is misleading because most of Earth’s water is salt water, frozen, polluted, or not located where people need it. Humans need to manage fresh water carefully because usable clean water is limited and unevenly distributed.