Non-Revenue Water (NRW) is defined by the International Water Association (IWA) as the difference between water distributed into the network and the water invoiced to customers. NRW results from various factors, including leaks, theft, unbilled authorised consumption, and metering inaccuracies. Reducing NRW not only addresses unsatisfied demand and increases utility revenues but also contributes to the reduction of carbon emissions associated with the energy intensive actions that accompany the production, treatment, and distribution of water.

Water utilities are essential components of the carbon footprint landscape. Every unit of water distributed by a utility carries a certain level of carbon emissions due to energy consumption in water extraction, treatment, pumping, and distribution. The reduction of NRW directly impacts the carbon footprint by lowering the amount of water lost and, consequently, the associated emissions.

MUWASA annually produces approximately 6,620,000 cubic metres of water, with an average NRW level of 43% (2,846,600 m3). The utility’s objective of NRW reduction is to align with the National goals by reducing NRW to 30% by 2024/2025.

Mitigation actions

MUWASA believes in a vital connection between reducing non-revenue water (NRW) and mitigating carbon emissions. This aligns with the  International Water Association’s LEI (Leakage Emissions Initiative) which is a forward-thinking approach that addresses the interconnected challenges of water loss and carbon emissions. It acknowledges how water utilities have the potential to become significant players in the effort to achieve carbon neutrality. The LEI encourages utilities to act by identifying and reducing leaks, as well as helps utilities to develop a program that will allow them to sell carbon credits.

With reference to this initiative, MUWASA initiated a NRW reduction project, with support from the French government focusing on three District Metered Areas (DMAs) within the utility’s service areas with of about 1,350 households.

Before the onset of the project, the NRW in these DMAs was initially at a staggering 70%, and this was reduced to 40% through a series of innovative solutions and activities with the support of CityTaps, an innovative water solution provider. Some of the interventions employed were;

• Active leak detection using collaborative leak activity reporting software.
• Detection of underground leaks using satellite image analysis.
• Replacement of all billing meters by Smart meters read automatically using an Advanced Metering Infrastructure (LoRaWAN network)
• Monitoring of Minimum Night Flow using bulk meters and GPRS loggers.
• Pressure management using a dual-set point Pressure Regulating Valve.
• Automatic calculation of the NRW balance.
• Real-time monitoring of key NRW indicators

The project contributed to a significant reduction of NRW by 30% (108,000 m3), with a correspondent decrease in greenhouse gas (GHG) emissions, i.e., 26 metric tons of CO2 equivalent per year. This was realised in a single DMA is only a small subset of the MUWASA network.

In Tanzania, the carbon intensity of electricity production is 367 grams of CO2 equivalent per kilowatt-hour (g/kWh). The electricity consumption of MUWASA is 4,273 MWH/year. With the aid of the IWAs LEI, MUWASA’s carbon intensity was calculated at 237 grams of CO2eq. per cubic meter (g/m3) of water.

Following the success of NRW reduction in the selected DMAs, MUWASA plans to extend the programme to cover the entire water distribution network. This expansion will further contribute to reducing carbon emissions to align with international sustainability goals.

Fig 1. Musoma city centre

Fig 2. Technical team

Fig 3. Leak detection activity

Fig 4. DMA inlet installation

Communication with citizens

MUWASA engages with citizens by carrying out awareness campaigns within the local community. During such programmes, special presentations on the challenges associated with water loss and the collective responsibility of everyone to detect and report leaks are shared with local schools and educational materials are also distributed to further enhance their knowledge.

Fig 5. community sensitization

Fig 6. School communication

The MUWASA story demonstrates the triple benefit of this approach. By actively reducing NRW, the utility not only addresses environmental concerns by protecting the natural resource, provides additional volume of water to the population, but also improves its financial sustainability. The reduction in carbon emissions not only aligns with global environmental goals but can also provide an additional revenue stream through carbon credit sales.

Water utilities in developed countries have regulatory obligations to reduce their carbon footprint and many have started taking actions in Europe and the USA. However, water utilities in developing countries, like MUWASA, should not be left behind. With the right support, adapted technological solutions and co-financing methodologies as the sales of Carbon Leakage Credits, these utilities can also bring their contribution and participate in the international efforts.