Teacher Answer Key
Our Water
Student Comprehension Questions
1. What is a water footprint?
A water footprint is the amount of water used to manufacture an item. Water footprints
can be measured for individual people, businesses, and even cities and countries.
2. Why is it important that people in California work to manage our water resources?
It is important to manage our water resources because water is used in California for
so many different things.
3. Name two industries that depend on water and are a big part of California’s economy:
agriculture and fishing
4. What happens when rivers don’t get enough water?
When rivers don’t get enough water, their fish can’t survive. Then, the fishermen,
restaurants, and other businesses that depend on fishing, can’t earn a living. The bears
and eagles also run out of their food source, and that affects the whole balance of nature,
wildlife and people!
5. What are some municipal uses of water?
fighting fires, watering parks, cleaning city streets
6. What are some household uses of water?
doing dishes, flushing toilets, watering gardens
7. What do you think is the most important water need? Why?
(subjective answer)
San Francisco Public Utilities Commission • SFWater.org • 1155 Market Street, San Francisco, CA 94103 • (415) 551-4730
Teacher Answer Key
Hetch Hetchy
Student Comprehension Questions
1. Why is getting enough water in California always an issue?
Getting enough water in California is always an issue because California
is a dry state that often has droughts.
2. How did people in San Francisco buy water during the Gold Rush days?
People bought water from barrels that were carried in carts or on the back of a donkey.
3. How do dams and reservoirs provide people with a water supply?
Dams are barriers that stop the flow of water so that it can collect into a large area, and
reservoirs are a large container or area that keeps the water in place for future use.
4. Why was the Raker Act so important for San Francisco?
The Raker Act was a law that gave San Francisco the rights to use water from
the Tuolumne River. This meant the city could dam the river and flood the
Hetch Hetchy valley to provide San Francisco with fresh water to meet all their needs.
5. How far does water travel from the Hetch Hetchy reservoir to San Francisco, and how
many residents in the Greater Bay Area use this water?
The water travels 167 miles and provides water to 2.4 million residents.
6. Why do you think it is important to save, or conserve water?
(subjective answer)
San Francisco Public Utilities Commission • SFWater.org • 1155 Market Street, San Francisco, CA 94103 • (415) 551-4730
Teacher Answer Key
Drought
Student Comprehension Questions
1. Name the five steps of the water cycle:
evaporates, condenses, precipitates, replenishes, accumulates
2. What is a drought?
A drought is when precipitation like rain and snow, doesn’t fall in an area for a long
period of time, and when water sources don’t get replenished. Water levels drop and
water shortages can happen.
3. How does climate change affect the global water cycle?
As our normal weather patterns change, there will be less precipitation in many
areas, and therefore, more droughts.
4. What does it mean when there is a water ration?
A water ration is when the government limits the amount and sometimes even the
ways people can use water.
5. What are six ways we can conserve water?
Make sure faucets and and pipes aren’t leaking
Turn taps tightly off after use
Wear clothes more than once before throwing into the laundry
Take shorter showers
Don’t let the water run when washing hands, brushing teeth or doing dishes
Eat less beef and more plant-based foods.
6. What will you do to help conserve water?
(subjective answer)
San Francisco Public Utilities Commission • SFWater.org • 1155 Market Street, San Francisco, CA 94103 • (415) 551-4730
Teacher Answer Key
Recycled Water
Student Comprehension Questions
1. What is wastewater?
All the water that leaves our sinks, showers, bathtubs, toilets, dishwashers, washing
machines, and garden hoses is called wastewater. This water has been used and is
no longer potable or drinkable.
2. What is a Wastewater Treatment Plant?
A Wastewater Treatment Plant is where wastewater and stormwater go to get cleaned
before being discharged, or sent to the San Francisco Bay and Pacific Ocean.
3. What is recycled water?
Recycled water is highly treated wastewater that has been purified, or cleaned
through many levels of filtering and treatment.
4. What can recycled water be used for?
Recycled water can be used to irrigate parks, playgrounds, golf courses, schoolyards
and wildlife habitats; and it can also be used for decorative fountains, commercial
laundries, cooling and air conditioning in buildings and street cleaning.
5. How does using recycled water help us conserve our drinking water supply?
Using recycled water helps us conserve our drinking water supply because it means
we can use recycled water for things like watering the lawn or flushing toilets, instead
of using our drinking water for these things.
6. What is the most interesting thing you learned about recycled water?
(subjective answer)
San Francisco Public Utilities Commission • SFWater.org • 1155 Market Street, San Francisco, CA 94103 • (415) 551-4730
Teacher Answer Key
Desalination
Student Comprehension Questions
1. What is freshwater and where can it be found?
Freshwater is not salty and is found in rivers, lakes, snowy mountain ranges, glaciers,
and underground in aquifers.
2. What percentage of all the water on Earth is available as freshwater for us to use?
0.34%
3. What is desalination?
Desalination means to remove salt and other minerals from salt water or seawater, in
order to make potable water which we can use for drinking, cooking and other uses.
3. What must be considered before building a desalination plant?
The future of marine life and coastal beauty must be considered before building a
desalination plant. They need to be properly designed to protect our environment.
4. What is brine and why is it important to dilute it before returning it to the sea or ocean?
Brine is a by-product or leftover that is created from the desalination process. It is very
salty and concentrated with minerals and must be diluted so it doesn’t harm or kill
marine life.
5. Why would building a desalination plant in the San Francisco Bay Area be helpful?
Since California is a dry state that often goes through periods of drought, building a
desalination plant in the Bay Area could provide a reliable source of potable water.
6. What is the most interesting thing you have learned about desalination?
(subjective answer)
San Francisco Public Utilities Commission • SFWater.org • 1155 Market Street, San Francisco, CA 94103 • (415) 551-4730
Teacher Answer Key
Groundwater
Student Comprehension Questions
1. What is groundwater?
Groundwater is water that exists beneath the earth’s surface.
2. What is an aquifer and how do they get replenished?
When enough groundwater is held in the saturated zone, and it can be used as a source
of water, that layer is called an aquifer. Aquifers are replenished whenever it rains.
3. Why is groundwater so important to plants and animals that live in wetlands and creeks?
Plants and animals depend on groundwater to provide water to wetlands, creeks and
other water bodies in natural areas where they live.
4. What does it mean to manage local groundwater aquifers sustainably?
Managing groundwater aquifers sustainably means that the aquifer is allowed to
refill itself so that we have an ongoing supply of water for the future.
5. What are pollutants and how do they impact groundwater?
Pollutants are harmful chemicals and if they soak through the earth, they can get into
the groundwater below and make the water unsafe to drink or use in other ways.
6. What is one way you can prevent pollutants from entering our groundwater?
One way to prevent pollutants from entering our groundwater is to never dump
pollutants on the ground.
San Francisco Public Utilities Commission • SFWater.org • 1155 Market Street, San Francisco, CA 94103 • (415) 551-4730