Climate change is water change. Increasing global temperatures and changing weather patterns are directly impacting flood risks, and the availability and quality of source waters. While the water sector has to cope with the impacts of climate change, it also contributes up to 10 percent of carbon emissions locally from its energy consumption, as well as contributing other greenhouse gases such as nitrous oxides and methane emissions from wastewater systems.

Fortunately, there are many promising ideas and solutions to decarbonize the water sector.

The demand for energy by utilities, which already accounts for between 10 – 35 percent of operating costs, is rapidly increasing. This is driven by lower quality source waters, and more stringent regulations on treatment processes to achieve high water quality standards. Increasing energy use efficiencies to reduce energy consumption, and transforming wastewater treatment plants into resource recovery and energy production facilities, will be vital for a carbon neutral future.

Globally, approximately 80 percent of wastewater is discharged into nature untreated. The emissions from untreated sewage represent three times the emissions of average energy intensive conventional wastewater treatments. A massive expansion of wastewater treatment is needed but, equally, wisely selecting technologies for service expansion is critical to put us on the path toward carbon neutrality.

Yet, the climate agenda is not the only global agenda. The Sustainable Development Goals and the New Urban Agenda are also setting ambitious goals for our planet, and the future development of our cities. Water connects these global ambitions.It is clear that the water sector can own solutions that contribute its share of reducing emissions, and to meeting the internationally agreed target to cap the global temperature rise below 2°C.


Achieving 100 percent access to water and adequate sanitation, and reducing untreated sewage by 50 percent, can be met with low-carbon, climate resilient urban water systems, contributing to the climate agenda and building water sensitive, liveable cities for our communities. Sustainable urban water, as defined in the IWA Principles for Water Wise Cities, will be a cornerstone in meeting these goals.

Integration of the water and climate agendas presents opportunities to unleash climate financing for utilities working hand in hand with their cities. This would allow them to simultaneously adopt energy efficiency and climate-smart mitigation measures to adapt their existing assets, and to plan necessary future service expansions, integrated in urban design.

The Water and Wastewater Companies for Climate Mitigation (WaCCliM) project is developing ECAM, a carbon and energy accounting tool, to help utilities invest wisely for their combined water and climate change challenges. WaCCliM is guiding water and wastewater companies on a journey to energy and carbon neutrality, pro-actively preparing utilities for future Greenhouse Gas and environmental regulatory compliance.

Emissions from the water sector are typically assessed in a fragmented way under different urban sectors. WaCCliM provides a holistic approach, interlinking the different stages of the urban water cycle, enabling a specific carbon accounting for the water sector. By preparing now, water utilities working with WaCCliM are becoming sector leaders, and are seizing the opportunity to become more efficient and effective in an uncertain future.

Find out more about the WaCCliM project and roadmap: WaCCliM_Decarbonizing the Water Sector

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Register for the World Water Congress & Exhibition in Brisbane and join us for a workshop on climate financing and a full day training on the ECAM tool:

Unlocking financial resources to decarbonize the water sector

Tuesday 11 October 15:30-17:00
Venue: Room 6

Assessing Climate and Energy Performance of Water and Waste Water Utilities 

Sunday 08 October 08:30-15:30
Venue: Room 2

In this training, experts on water and waste water technologies will be trained to become international Water, Climate and Energy (WEC) advisors.   Via hands-on tutorials and group discussions, participants will learn to use the Energy performance and Carbon Emissions Assessment and Monitoring (ECAM) tool.

Good news for the sector: water is well represented in the newly launched Sustainable Development Goals (SDGs). This led to shared optimism during the World Water Week 2015 in Stockholm, this August. Not only is there a specific goal (SDG 6) devoted to water; but water also features prominently in four of the other SDGs.

The number of SDGs, seventeen in total, reflects well the importance and urgency of the sustainability agenda. Moreover, it indicates the interconnectedness and complexity of the issues to be tackled in the next 15 years. Not a minor task. But the question is, are these goals far-reaching enough? Which ‘smart’ measures can we practically take to achieve actual sustainable (urban) development?

Killing multiple birds with one stone

To meet all targets by 2030, and avoid focusing too much on certain aspects and neglecting others, a holistic approach is required. An integrated strategy of energy efficiency aimed at reducing energy consumption and reducing operating costs, combined with the critical aspect of reducing the discharge on untreated sewage is needed.

One example of this approach is the Water and Wastewater Companies for Climate Mitigation (WaCCLiM)* project.  This has highlighted the fact that carbon emissions from untreated wastewater represent a major source of greenhouse gas emissions from the urban water cycle. Implementing the SDG 6 goal ‘smartly’ can potentially reduce these emissions to zero, contributing to the carbon reduction goals discussed at the upcoming COP 21 in Paris. Smartly means a manner in which energy production from wastewater is implemented and efficiency increased, without compromising the service level and even reducing costs. Cost reductions from energy savings provide an opportunity for utilities to expand their service cost-effectively. In addition, if we were to find a way of “pricing” greenhouse gas emissions from untreated sewage, we would further incentivise both the extension of wastewater treatment and the reduction of greenhouse gas emissions.

Do-It-Yourself for utilities

A great challenge for utilities lies in finding and implementing suitable measures to realise such ‘win-win’ situations. The WaCCliM project specifically aims to facilitate this process. Its objective is to support utilities on the path towards climate neutrality. Pilot projects in Peru, Mexico and Thailand show high potential for successful implementation of ‘energy efficient’ and low carbon measures. These measures include biogas co-generation, increased pump efficiency, a reduction of leakages and sending treated effluent to crops. All of which can contribute to reduce operational costs, improve utilities’ service to the public and protect the environment.

Identifying such practical opportunities requires the correct interpretation of sufficient ‘reliable  data’. This is why the Energy and Carbon Emissions Assessment and Monitoring (ECAM) tool has been developed to assist utilities to make the most of available resources and monitor their progress. Motivating utilities to implement a low energy – low carbon approach can be a stepping stone to inspire a change of mindset when planning replacements or extensions, and eventually a stepping stone to carbon neutral cities.

Although this ‘DIY’ tool for utilities can be an impactful starting point, an enabling environment, in which all stakeholders are involved is also critical. Engaging with national governments and the international water and climate community is essential.

The adoption of this smart water-energy-carbon ‘nexus’ approach by water and wastewater utilities around the world won’t happen by chance. It needs multiple stakeholders to commit to the post-2015 sustainability and development agenda to ensure a sustainable urban water cycle. Only then can the journey towards regenerative cities make real progress.


*The Water and Wastewater Companies for Climate Mitigation (WaCCliM) project is implemented by the International Water Association (IWA) and GIZ (Deutsche Gesellschaft für Internationale Zusammenarbeit), on behalf of the German Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB).


If you missed the Stockholm World Water Week, you can access the presentations delivered at the seminar “Water-energy-carbon nexus – its relevance for water and wastewater utilities” below:

Introduction to WaCCliM

Water-Energy-Carbon in Water and Wastewater Utilities Today and Tomorrow

How can energy and carbon balances be analysed and monitored in water and wastewater systems? The WaCCliM assessment tool applied to cases in Mexico, Peru, Thailand

Understanding that data collection and management is essential to making sound decisions on energy and carbon investments The WaCCliM experience from Thailand

Political and institutional framework conditions to facilitate energy efficiency and climate mitigation in Mexico’s water sector

The need to act on curbing greenhouse gas emissions to avoid a dangerous rise in global temperature is well known. While national governments are working their way to reach a global carbon accord in Paris later this year, much can be done at local level to turn the tide. Cities and their citizens can make a lasting contribution by changing their habits and practices. Largely unknown outside the water sector, is the opportunity that exists to change the energy and carbon footprints of the urban water cycle: the way we manage and discard our water and used waters.

The energy used to supply water to cities and clean used water is responsible for 3 – 8% of global greenhouse gas emissions. This is roughly similar to all global air traffic emissions. Increasing energy efficiency and producing energy from the urban water cycle can result in ‘urban water’ becoming a net energy producer and can even achieve carbon neutrality. This would not only help to curb a good chunk of greenhouse gas emissions, it would also reduce the energy bills of consumers, utilities and industries alike.

Ruhrverband, a German water utility, for example, has worked for more than a decade on reducing their energy and carbon footprint. They now manage to deliver water and to clean used water, in a close to energy and carbon neutral fashion. Efficiency gains have been integrated with producing green energy. The efficiency gains have come from painstakingly fixing leaks and installing energy efficient appliances such as pumps and aeration systems. The green energy production is derived from generating (hydro) power from the water supply stored in the reservoir, and producing biogas from used water and other organic solid waste.

Around the world, other utilities are now following this example. Recent studies carried out by the IWA show that utilities in Mexico, Peru and Thailand can reduce their carbon emissions by between 20 – 35% in a relatively easy way: fixing leakages and producing hydropower from water running in pipes.

While utilities can contribute significantly, an even more astounding contribution to reduce the energy and carbon footprint of water use can be made by citizens. About 60% of household level energy is used to heat water for cooking, showering and washing. Over the last decade we have already seen a significant increase in efficiency at household level of water use. For example, in Europe, the introduction of water efficient appliances such as washing machines and shower heads has made s ignigicant difference.

As a result total water consumption is falling year by year. New technologies are now appearing on the market to capture the heat that is put in water and re-using rather than leaking it away in drains and sewers. Highly efficient water boilers, heat exchange appliances in showers and ever more efficient washing machines.

Utilities and their leaders have a major role to play in the transition of the energy footprint of the urban water cycle. Well within their reach is the development and implementation of energy savings and production plans that reduce costs and make their operation far less affected by fluctuating energy prices. Through informing their household clients, they can be pro-active and help consumers change behavior and reduce energy and water consumption. In connecting to industry they can be pivotal in transforming the total urban water cycle and its energy footprint. Yet, they can’t do it alone.

To enable the required transformation we need the powerful combination of entrepreneurship and regulation to be aligned. Creating a market for more efficient appliances needs regulation to allow market entry of new technologies and incentives to end wasteful usage. Allowing and stimulating pilot schemes to demonstrate proof of concept and practice is critical as a stepping stone to wide-scale adoption. Reviewing water and energy tarifs while water and energy saving technology become widespread can be a further stimulus in the transition.

However, impact and progress will only happen by bringing along consumers and citizens. To alter the energy footprint of the urban water cycle, citizens and consumer organizations can play a key role. Bringing citizens’ groups together to develop collective action, for example at neighborhood level, can become emblematic to change paradigms and practices. Engaging citizens in the urban water cycle energy transition is a fantastic way to connect many more people to the needed action to curb greenhouse gas emissions. Let’s act together and act responsibly and swiftly as we have little time to loose.

As the COP20 climate talks enter their second week, they still represent the greatest opportunity to pave the way for a binding global deal that recognizes and prioritizes the links between climate adaptation, mitigation and resilience. However, focusing on water resources as a common denominator between the strategies could provide critical momentum to driving change.

Water is the primary medium through which climate change impacts humans, society and the environment. Water resources management that builds on ecosystem-based approaches is essential for securing resilience and a key component in disaster risk reduction. Water is also critical for successful climate change mitigation, as many efforts to reduce carbon emissions depend on reliable access to water resources.

The impact of water related hazards may exacerbate inequalities and are disproportionately borne by poor and vulnerable communities. More than 1.6 billion people live in areas suffering water scarcity, a number expected to rise to 2.8 billion over the next decade. Gradual sea-level rise poses an additional threat to coastal communities and economic activities.

Water wise strategies supporting resilience and disaster risk reduction are fundamental for the provision of safe water, livelihoods and sustainable energy sources. Supporting the sustenance, preservation and restoration of healthy ecosystems will increase resilience to water related disasters. Including key water resources management functions in adaptation planning processes will help in coping with both increasing climate variability and long-term shifts in climate conditions.

Water and wastewater companies are typically energy intensive. Between 10% and 35% of operational costs are on energy consumption, and the water sector contributes between 2-5% of global carbon emissions, as well as contributing towards other greenhouse gas emissions such as nitrogen oxides and methane, which drive climate change and extreme weather events such as floods and droughts. Addressing the challenge of greenhouse gas reduction and improved energy efficiency within the water cycle must become central to water management strategies globally.

This can also be done when applying adaptation strategies such as reducing freshwater consumption, recycling, or rainwater management, as these strategies also contribute to avoiding energy consumption and are therefore linking adaptation and mitigation approaches.

This indicates clear opportunities for improving energy efficiency and greatly reducing greenhouse gas emissions through more energy-efficient systems, as well as recovering energy, nutrients and other materials from wastewater. Energy efficiency, energy production and resource recovery in the water sector can make a significant contribution to reducing energy demand and diminishing carbon emissions. Yes, more innovation and new technologies are required, but this is not a pipe dream for the future: these technologies are available to us today.

The water sector can become more energy efficient by 2030 through major efficiency gains and by producing energy from wastewater treatment. Investment in these technologies can reduce water management costs. Recovering energy, and other resources, from the water and wastewater cycle provide further opportunities to establish a cyclical economy and make a major contribution to sustainability.

Viewed from this perspective, water will determine how economic development, human well-being and environmental sustainability will be achieved, as well as being critical to climate change adaptation and mitigation strategies. Developing sustainable solutions for optimizing the water – energy – climate linkages will require technological innovation and close cooperation between sectors. The water – energy – climate linkages are at the heart of creating the sustainable economy of tomorrow.

Together with Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ), and acting on behalf of the German Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB), the International Water Association is working with water utilities in three countries on the Water and Wastewater Companies for Climate Mitigation project. The project works across local, national and international levels, and engages with national stakeholders in three pilot companies in Mexico, Peru and Thailand. The objective is to use greenhouse gas emission-reducing technologies to improve the carbon balance of water and wastewater companies while maintaining or even improving service levels and improving these companies cost effectiveness.

The Water and Wastewater Companies for Climate Mitigation project shows how the water sector can reduce its greenhouse gas emissions and contribute to climate change mitigation.

In Lima, we will co-organise a side event with partners from around the world to build recognition of the links between climate adaptation, mitigation and resilience, with water resources as the common denominator between the strategies. The side event will showcase experiences and lessons learned in areas related to water management, energy efficiency, sustainable drainage systems, catchment protection and management and the promotion of policies which improves adaptive capacity and builds resilience, while aiming at stabilising or reducing greenhouse gas emissions.

GIZ recently signed a Memorandum of Understanding (MoU) with the Wastewater Management Authority (WMA) at Thailand’s Ministry of Natural Resources and Environment for the Thai-German cooperation on ‘Water and Wastewater Companies for Climate Mitigation (WaCCliM-Thailand)’.

The project is part of the global WaCCliM project that includes Thailand, Mexico and Peru and aims atimproving the carbon balance of water and wastewater utilities through the introduction of greenhouse gas reduction technologies. WaCCliM is a joint initiative between GIZ and the International Water Association (IWA), acting on behalf of the German Federal Ministry for the Environment, Nature Conservation, Building and Nuclear Safety (BMUB). It runs from January 2014 to January 2019.