NCWR - Non Conventional Water Resources

In a nutshell

In this activity we ‘explore’ the urban water cycle and we learn what sustainable water management within a city is all about.

1 class hour

12-13 years old

In the field

Our objectives

In this activity you will:

Find out how the human activities impact the water cycle.
Discover how the water cycle works in an urban environment.
Be informed about the practices of sustainable water management.
Be motivated to consume water responsibly.

Things to use

Notebooks and pens, photo camera (or a cell phone to take photos)

Water-readings

Three water systems in a city

Cities are big consumers of water! In most cases its water is transferred from far away. This way its water “inflow” relies not only on precipitation in the surrounding areas but also in others from where the water is transported to the city. After being collected, water is treated and distributed through an underground pipeline network, the water supply system. Apart from river dams, lakes and reservoirs, precipitation and groundwater the water supply system may rely on seawater through desalination hat is the case of many arid areas, such as the Mediterranean islands.

On the other hand, the city returns water (after its use by houses, offices, shops, hotels, etc.) as wastewater. Wastewater is progressively recognized as an alternative (non-conventional) water resource after its treatment and under controlled conditions.

In a city, when rainwater is not absorbed by the soil usually drains into the rainwater drainage system. This is a network of channels and pipelines ending either into a river or the sea. This drainage system needs to be properly designed and maintained so that the city does not flood. The large amount of sealed surfaces (e.g. streets, highways, pavements, buildings, etc.) block the rainwater from being absorbed, reducing and enrichment of the groundwaters.

In this context, there are three systems that are crucial in how the urban water cycle operates: water supply, wastewater and rainwater drainage system.

Stop and wonder

Discuss in class:

How should a city’s well-designed and well-maintained rainwater system look like?
Who is responsible for the system’s design and maintenance?
What role can the citizens play?

Play & learn

Observe the pictures and choose the system they belong to (supply, sewage or rainwater drainage).

Water Supply system

Sewage system

Rainwater drainage system

city_rain01

Water supply system

Sewage system

Rainwater drainage system

city_wastewater_01

Water supply system

Sewage system

Rainwater drainage system

city_watersystem01

Water supply system

Sewage system

Rainwater drainage system

city_rain02_Jim.henderson _wiki_CC

Water supply system

Sewage system

Rainwater drainage system

city_wastewater03

Water supply system

Sewage system

Rainwater drainage system

city_rain03_greywateraction.org

Water supply system

Sewage system

Rainwater drainage system

Play & learn

The urban water cycle

Drag and drop the labels that refer to processes of the water cycle as well as to activities related to water management.

1 1 precipitation
2 2 reservoir of the water supply system
3 3 wastewater treatment plan
4 4 water collection in a dam
5 5 desalination plant
6 6 evaporation
7 7 condensation
8 8 surface run-off
9 9 water for irrigation
10 10 greywater recycling

Water-readings

Water management in a city

In cities, population and water demand is concentrated to a relatively small, dense area. This concentration increases the pressure on the water resources. Water management in a city should assess the supply and demand relation and to reduce the impacts of urbanization to the natural water cycle. The study of water supply and demand relation, the promotion of water recycling, the handling of leakages, the maintenance of water infrastructures are among the tasks of a Water Services Company.

So in a city, sound water management means:

To ensure enough water of good quality for all.
To maintain the water supply network in order to avoid leakages.
To monitor the water quality.
To monitor the amount of available water for the city.
To conserve the quality of the water resources.
To properly design green spaces in and around the city (parks, streams, greenbelts, etc.).
To maintain the storm/rainwater system so as to avoid flooding.
To harvest and use rainwater achieving water saving and reducing the risk of flooding.
To use the recovered water and the sludge from the sewage treatment plant.
To raise awareness of the citizens in order to save and use water properly.

Play & Learn

According to what you have read so far, which of the following corresponds to a sound water management in a city?

A broken pipe leaks for hours.

A 24-hour hotline to report problems (leakages, damages, etc.)

Sealed surfaces in parks.

Distribution of a brochure to consumers with water saving tips.

Overflowing grids when it rains.

Rewarding consumers who reduce water consumption (e.g. with reduced bills).

Green roofs and terraces

Water shares

Water meter

Way forward

Dive in…

Do you know about grey water? if you want to remember what greywater is

Wastewater treatment if you want to remember what black water is

Go back to the homepage!

Water in the city

In a nutshell

Our objectives

Things to use

Water-readings

Three water systems in a city

Stop and wonder

Discuss in class:

Play & learn

Play & learn

The urban water cycle

Water-readings

Water management in a city

Play & Learn

Water shares

Water meter

Way forward

Dive in…

Water works through time

Water in the city

The water basins

Desalination

Greywater recycling in practice

Do you know about grey water?

Wastewater treatment

Rainwater Harvesting Systems in practice

Rainwater harvesting

Reduce-Reuse-Recycle

Acting for Climate

Climate change: Why should I care?

Water resources

The water cycle

Where do I begin?