From Wastewater to Water Resource: Understanding Wastewater Reuse and the Circular Water Economy in Saudi Arabia

Every day, we use water at home, at work, in restaurants, hotels, hospitals and businesses. We turn on a tap, take a shower, wash clothes or clean our homes, and then the water disappears down a drain.

But where does it go?

For most people, wastewater is simply something that needs to be taken away. In reality, treated wastewater can become a useful resource when it is properly collected, treated, monitored and reused.

This is particularly relevant in Saudi Arabia. The Kingdom has limited natural freshwater resources and has invested heavily in water supply, desalination, wastewater treatment and related infrastructure. At the same time, Saudi Arabia is working to increase the reuse of treated wastewater as part of its wider approach to water security and sustainable resource management. A World Bank assessment reports that Saudi Arabia has plans to increase treated wastewater reuse to at least 70% by 2030. (World Bank)

So, what happens to wastewater after we use it, and how can it become part of a more sustainable water system?

What Happens to Wastewater in Saudi Arabia?

Wastewater comes from many parts of everyday life.

At home, it comes from toilets, showers, sinks, washing machines and kitchens. Restaurants, hotels, offices, hospitals and other facilities also produce wastewater. Industrial facilities can generate wastewater with very different characteristics depending on their activities.

Where sewer networks are available, wastewater is collected and transported to treatment plants.

At a treatment plant, wastewater goes through a number of processes to remove solids, organic matter and other pollutants. Depending on the treatment system and the intended use of the treated water, additional treatment and disinfection may also be required.

The important point is that treated wastewater is not all the same.

Water quality needs to be appropriate for the intended use. Water that has been treated for landscaping, for example, does not automatically mean it is suitable for every other application.

Once treated to the required standard, however, wastewater can potentially be reused instead of simply being discharged.

This is where wastewater starts to become a resource rather than just a waste stream.

Why Is Wastewater Reuse Important in Saudi Arabia?

Saudi Arabia’s water situation is different from countries that have abundant rainfall, rivers and freshwater lakes.

The Kingdom has limited natural freshwater resources, while its cities, industries, agricultural activities, tourism developments and communities require reliable water supplies.

Desalination is an important part of Saudi Arabia’s water system, but wastewater reuse provides another opportunity: making better use of water that has already entered the system.

The principle is quite simple.

If water has already been used once, properly treated water may be suitable for another purpose.

This does not mean that treated wastewater should be used for everything. Instead, the goal is to match the quality of treated water with the purpose for which it is required.

Saudi Arabia’s National Water Strategy 2030 includes improving water demand management, delivering effective water and wastewater services, and safeguarding and optimising the country’s water resources. (Saudi Ministry of Environment)

In this context, increasing the reuse of treated wastewater can help make better use of an existing resource.

How Can Treated Wastewater Be Reused?

One of the most visible applications is landscaping and irrigation.

Saudi cities and new developments increasingly include parks, green spaces, roadside landscaping and other planted areas. These require regular irrigation, particularly in a hot and dry climate.

Where the relevant requirements are met, treated wastewater can be used for suitable irrigation applications.

There are also opportunities in industry.

Some industrial activities require water for cooling, washing, cleaning and other purposes but do not necessarily require drinking-water quality. Properly treated reclaimed water can potentially be used for suitable applications when it meets the required standards.

Other possible non-potable uses can include certain construction activities and dust-control applications, depending on the requirements of the specific project.

The key idea is fit-for-purpose water.

Instead of asking only, “Can wastewater be reused?”, we should ask:

“What level of treatment is required for this use, and can the treated water be supplied safely and reliably?”

This approach helps ensure that water reuse supports both resource efficiency and public health.

What Exactly Is a Circular Water Economy?

The traditional way of thinking about water is often linear:

Take → Use → Treat → Discharge

A circular water economy tries to close that loop:

Use → Collect → Treat → Reuse → Recover → Use Again

The idea goes beyond simply recycling water.

Wastewater treatment can also create opportunities to recover other resources, including energy and nutrients, depending on the treatment system and local conditions.

The World Bank describes water reuse as an opportunity to create a reliable, climate-resilient source of water for cities and industries facing increasing pressure on traditional water supplies. Its 2025 report also highlights the importance of fit-for-purpose treatment, appropriate regulations and investment in scaling water reuse. (World Bank)

For Saudi Arabia, this way of thinking is particularly relevant. The question is not only how to produce more water, but also how to get more value from water that is already available.

Why Should Ordinary Residents Care?

Wastewater management may sound like an issue for governments, engineers and treatment-plant operators.

But it starts with everyday behaviors.

Every time we use water, we create wastewater. What we put down our drains and how much water we use can affect the wider system.

There are simple things individuals can do.

We can fix leaking taps and toilets, avoid leaving water running unnecessarily, and use water carefully when washing cars, cleaning homes or watering plants.

We should also avoid putting oils, paints, chemicals and unsuitable materials into drains. These substances can interfere with wastewater treatment and create additional environmental and operational problems.

Businesses have an important role as well.

Restaurants, hotels, offices, commercial buildings and industrial facilities can monitor their water consumption, reduce unnecessary use and identify opportunities for water reuse where appropriate.

Communities can contribute by treating water as a valuable resource rather than something that is available without limits.

These actions may seem small when considered individually. But across a city or a country, responsible water use can make a meaningful difference.

What Practical Challenges Does Saudi Arabia Face?

Increasing wastewater reuse is not simply a matter of building more treatment plants.

One major challenge is infrastructure.

Wastewater needs collection networks, treatment facilities, storage and distribution systems. If treated water is available but there is no suitable network to deliver it to users, its reuse potential is limited.

Another challenge is water quality.

Different uses require different treatment levels. Continuous monitoring and appropriate controls are therefore essential to ensure that reclaimed water remains suitable for its intended purpose.

There are also economic considerations.

Treatment, pumping, storage and distribution all require investment. In some locations, transporting treated water over long distances may not be practical or economical. Reuse planning therefore needs to consider both where wastewater is generated and where treated water can be used.

Public understanding and confidence are also important.

The word “wastewater” can naturally make people uncomfortable. Clear communication is therefore needed to explain that treated wastewater intended for reuse must meet the applicable requirements for its intended use.

Finally, wastewater reuse involves many stakeholders, including regulators, municipalities, utilities, developers, industries, treatment-plant operators and the public.

Successful reuse requires coordination between all of them.

What Could the Future Look Like?

Saudi Arabia’s continued development provides an opportunity to include water reuse in the planning of new cities, tourism destinations, industrial areas and other major developments.

Instead of considering wastewater only after a project has been developed, planners can think from the beginning about where wastewater will be generated, how it will be treated and where reclaimed water could be used.

Technology can also support this process.

Modern sensors, online monitoring, automation and data systems can help operators monitor treatment performance and water quality more effectively.

The wider global water sector is also moving towards greater use of treated wastewater for municipal and industrial purposes. The World Bank’s 2025 water-reuse report describes treated wastewater as a potentially reliable and sustainable source of “new water” for cities and industries, particularly where water stress is increasing. (World Bank)

For Saudi Arabia, this means wastewater management can increasingly be viewed not only as an environmental responsibility but also as part of long-term water planning.

What Can We Do Today?

A circular water economy does not have to happen at all at once.

It can develop through practical steps.

For individuals, that means using water responsibly and avoiding unnecessary wastage.

For businesses, it means looking for ways to reduce consumption and reuse water where appropriate.

For developers and communities, it means considering water reuse when planning infrastructure and landscaping.

For treatment-plant operators, it means maintaining reliable treatment, monitoring and quality control.

And for decision-makers, it means continuing to develop the infrastructure, regulations and investment needed to make water reuse practical at a larger scale.

The goal is not to reuse every drop of wastewater regardless of circumstances. The goal is to recover and reuse water safely and economically wherever it makes sense.

From Wastewater to Water Resource

Saudi Arabia’s water story is not only about producing more water. It is also about making better use of the water that is already available.

Treated wastewater can support landscaping, irrigation, industrial activities and other suitable non-potable applications. At the same time, effective wastewater management can reduce pollution and create opportunities to recover additional resources.

There is no single solution that will work everywhere. The right approach depends on local infrastructure, water quality, regulations, economics and the needs of each community or project.

But the underlying idea is simple:

Wastewater does not necessarily have to be the end of the water cycle.

For people living in Saudi Arabia, the circular water economy may sound like a technical concept. In reality, it starts with something very familiar: the water we use every day.

The more efficiently we use water, the more carefully we manage wastewater, and the more opportunities we create to safely reuse treated water, the closer we move towards a more resilient and sustainable water system.

Water may be used once, but with the right approach, it does not always have to be used only once.

Sources

• Ministry of Environment, Water and Agriculture (MEWA), National Water Strategy 2030. (Saudi Ministry of Environment)
• Ministry of Environment, Water and Agriculture, information on treated wastewater reuse and national reuse targets. (Saudi Ministry of Environment)
• World Bank, Scaling Water Reuse: A Tipping Point for Municipal and Industrial Use, 2025. (World Bank)
• World Bank, Saudi Arabia wastewater reuse sector assessment.  (World Bank)