Intermittent water supply systems and their resilience to COVID-19: IWA IWS SG survey

There is limited information about the current state of intermittent water supply (IWS) systems at the global level. A survey was carried out by the Intermittent Water Supply Specialist Group of the International Water Association (IWA IWS SG) to better understand the current state of these systems and challenges that water companies may have faced under COVID-19 pandemic and to capture successful management strategies applied by water utilities. The survey consisted of three parts: (1) general information about IWS systems, (2) current state of IWS and (3) resilience of IWS under COVID-19 conditions, as well as some questions about potential interventions in order to improve system performance in general and under future uncertain conditions. The survey responses were evaluated based on the Safe & SuRe resilience framework, assessing measures of mitigation, adaptation, coping and learning, and exploring organisational and operational responses of IWS utilities. Infrastructure capacity and water resources availability were identi ﬁ ed as the main causes of intermittency in most water distribution systems, while intermittent electricity was considered as the main external cause. Participants indicated that some risk assessment process was in place; however, COVID-19 has surpassed any provisions made to address the risks. Lessons learnt highlighted the importance of ﬁ nancial resources, e-infrastructure for ef ﬁ cient system operation and communication with consumers, and the critical role of international knowledge transfer and the sharing of best practice guidelines for improving resilience and transitioning towards continuous water supply.


INTRODUCTION
About 2.2 billion people worldwide lack access to safely managed drinking water (WHO/UNICEF ). This includes 1.3 billion with intermittent access (Charalambous & Laspidou ). In Target  occasional. The supply schedule varies a great deal in different locations; consumers could be without water for several hours in a day or several days in a week. The pattern of supply could be fixed, variable or unreliable. Operating water systems intermittently have a great deal of negative consequences for utilities, consumers and society at large including: rapid asset deterioration, more leaks and bursts (Klingel ), water quality issues (Kumpel & Nelson ), loss of income for utilities, inequity (Gullotta et al. ), financial burden for consumers (Burt et al. ) and public health (Ercumen et al. ; Bivins et al. ).
In the Sustainable Development Goals (SDGs), there is a requirement of a paradigm shift with a focus on sustainable service delivery. Intermittent water systems are very complex, and their efficient operation and management in order to deliver equitable supply to all the consumers remains a major challenge. The technical, social, financial and institutional challenges are exacerbated when multiple stressors affect the water systems simultaneously. Outbreaks of disease magnify these challenges of IWS systems. Previous to the COVID-19 pandemic, other outbreaks have demonstrated the importance of access to safe drinking water in strengthening resilience, promoting economic stabilisation and recovery of communities (ILO ). The full impact of COVID-19 on the water sector remains unclear. However, constraints such as water resources (Abolnga ), infrastructure capacity, social distancing and financial burdens could negatively impact the ability of water infrastructure to function successfully (Simukonda et al. b). Delivery of safely managed water services has significant health, environmental and economic benefits. Cotterill et al. () highlighted that the resilience of the economy and wider society to the COVID-19 pandemic largely depends on key workers and organisations to respond to, and adapt, in order to maintain performance of key services such as water systems.
A recent report by UN shows that countries that had made more progress in achieving the SDG6 (access to clean water) had more success in mitigating the COVID-19 risk (UN a). It is widely acknowledged that without progress on SDG6to ensure availability and sustainable management of water and sanitation for all by 2030the other SDG goals and targets cannot be achieved, due to high interdependencies between different goals (UN-Water ). The UN (b) has launched the SDG6 Global Acceleration Framework to improve progress on SDG6; as at the current rate, the targets will not be achieved by 2030. The framework has a number of pillars including that of 'Accelerate'. The five accelerators include optimised financing, improved data and information, capacity development, innovation and governance. The practitioners and utilities have the ability to impact millions of residents by improving water supply provision, which in turn can deliver multiple benefits across several SDGs.
The COVID-19 pandemic has emphasised that ensuring safe and reliable water services is critical. COVID-19 presents an opportunity to strategically rethink the way IWS systems are managed to enhance the effectiveness of resilience strategies -Resistance, Reliability, Redundancy and Responsein the water sector (UK Cabinet Office ), to react to and absorb the short-and medium-term impacts of COVID-19. This could be done by assessing water utilities' experiences before and during the COVID-19 pandemic to understand their technical, financial and social challenges, and provide learnings to minimise the impacts of similar events in the future, without jeopardising achievement of long-term environmental (natural resources) and economic (sustainable capital investment) goals. The focus will be on efficient operation and management of water systems, ensuring contribution to improved water availability, accessibility and affordability, while supporting long-term sustainable and resilient water systems by transition to continuous supply of water. Such systems will be able to bounce back after disaster (SDG9), improve the level of service for all users and enhance social equity (SDG10), and alleviate public health-related issues (SDG3) associated with lack of water or poor water quality.
The survey was carried out to understand key challenges and to capture successful strategic, tactical and operational management practices applied by water utilites operating under IWS conditions in the context of the COVID-19 pandemic. Based on the needs of different local settings, the challenges and knowledge gaps (understanding the dynamics of water demand, water quality, tariff systems, availability of alternative resources and supply systems, supply chain issues, shortage of skilled personnel and opportunities for digitalisation, and technical capabilities) were identified.

METHODS
The main aim of the survey was to understand the resilience of water utilities before and during the COVID-19 pandemic. The focus was on in-depth understanding of the issues, key challenges/barriers, capabilities and needs at each local context considering data/tool availability and technological, and financial and policy constraints. This information is a prerequisite to propose interventions to improve their performance and assess progress towards

Survey responses
In all, 63 responses were received. Only 25 responses were considered in the analysis of the survey as other responses were incomplete. The main observation from the incomplete responses was that a majority of them stopped at the beginning of part 2 of the questionnaire. This indicates that the willingness to contribute was there; however, a probable lack of quantitative information about these systems prevented the completion of the survey. Twenty-five responses are not large enough to be able to generalise the findings of this survey. However, the participants have suggested that knowledge transfer and learning from best practice is a requirement in order to make progress in improving or converting these systems from intermittent to continuous supply. This makes the survey even more relevant and highlights why such surveys and data collection are important for IWS systems.

Analysis of responses in part 1general information
Geographical distribution of participants Figure 3 shows the geographical location of participants. • Latin America (Brazil (1), Mexico (2)) • Middle East and North Africa (Iran (1), Iraq (1), Jordan

The distribution of participation and number of participants
(1), Lebanon (2), Palestine (1)) • Sub-Saharan Africa (Kenya (1), Zambia (2), Zimbabwe (2)) • China and Central Asia (Nepal (1)) • Indian subcontinent (India (4)) • Asia Pacific (Philippines (1), Malaysia (1)) There was one response from a participant working in utility in Romania. One response was from France (research institute) and one from Portugal in which the participant was from a technology supplier organisation. Finally, one response was from an academic who did not disclose in which location they work. The incomplete responses were from countries including Argentina, Bolivia, Croatia, India, Kenya, Myanmar, Peru and Senegal.

Type of IWS systems
The types of supply pattern of IWS systems in 23 participants' countries (two participants did not disclose this information) can be categorised as: • Fixed (9 cases)the supply time and volume of water are known • Variable (9 cases)the supply time is not known, but the volume of water is known This shows that even the limited access to water is not guaranteed in more than 50% of cases.
Factors contributing to intermittency of supply  Issues with operation of IWS systems prior to COVID-19 Figure 6 shows the issues that participants were dealing with prior to the COVID-19 pandemic. The figure shows that leakage and insufficient pressure in the systems were the main issues that the majority of participants were dealing with.
Transition to the continuous supply system  The Safe & SuRe framework was used to analyse responses on the state of IWS during the COVID-19 pandemic.
Interventions identified and implemented with the aim of increasing system resilience have been mapped onto the framework with results displayed in Figure 8.
The framework has been applied using the top-down approach with the threat of COVID-19 initially identified.  Only four participants mentioned that COVID-19 has caused some changes in the intermittency of supply, while seven mentioned no changes, and the remaining participants were not sure. There were contrasting impacts observed in different settings. For example, in one case, electricity load shedding by other users resulted in the water company having access to electricity 24/7. This resulted in the company increasing supply hours from 4 to 6 hours per day to 12 hours per day. The increased supply of water resulted in customers, who were typically reluctant to pay their bills, to pay. In another case, due to an increase in electricity price during the peak season (summer) and a reduction in the water company's revenues, the intermittency of supply worsened.
Unanticipated challenges identified included three participants noting that consumers not paying their bills resulted in a reduction in revenue. Others observed increases in residential demand, in one case by 40%, and also changes in hourly consumption patterns. One other case noted an increase of 10% in system input, identifying more illegal connections as maintenance work continued during lockdown. Walton () highlighted that, based on data from IBNet, the global average urban water use is typically 70% residential and 30% commercial, this split during COVID-19 is 82% residential and 18% commercial. This can be problematic as commercial users are more metered and are one of the main sources of revenue for utilities and in some places, they subsidise residential users. An increase in demand due to COVID-19 and a dry summer, along with having limited capacity to replace the elder workforce while they were shielding, pressure deficiency in urban water systems and in some cases water quality issues were also all noted as unanticipated challenges. The COVID-19 pandemic acted as a threat multiplier (Neal ), as interaction with weather events, or degree of intermittency in electricity in some cases, resulted in cascading failures.
Water demand increases due to COVID-19 and a dry season, in combination with an increase in electricity prices, resulted in a reduction of duration of water supply.
While in other cases reduced impacts and subsequent consequences improved the adaptability and coping level of the system, as a reduction in electricity demand resulted in an increase in the duration of water supply. Interventions or actions taken by water companies to reduce the impacts and consequences on the system are highlighted in Figure 8 and outlined below. Regarding the future operation of IWS, more digital utilities was suggested along with a perceived need for more risk assessments to be carried out, along with an increase in the need for preparedness.

Intervention measures implemented
It was suggested that a loss of income could force utilities to adapt to pre-paid metering, as a lack of income may result in poor operation. An increase in the maintenance and assessment of service was also suggested as a requirement to increase resilience, along with further exploration of alternative financial options. 50% of participants agreed that the COVID-19 pandemic will change investment priorities in resilience, while 23% suggested that it will not happen due to financial constraints.
The majority of the participants (70%) indicated that utilities will need support through this crisis and beyond.
Suggestions on the types of support required differed and included: • National level: Financial and human resources, strategic organisational guidelines, specific standards for planning and management of these systems as well as vulnerability assessments.
• Changes in intermittent energy supply had cascading positive and negative impacts on IWS; improved energy supply led to improved water supply and revenue; reduced energy supply and revenue increased IWS, thus illustrating the fine line between a virtual and vicious water supply cycle.
Leakage and insufficient pressure were identified as main issues in operation of IWS systems, followed by infrastructure and water quality issues. Increasing treatment plant capacity, rehabilitation of mains, metering and pressure management were mentioned as some of the measures that are being implemented by 50% of the utilities, in order to facilitate transition towards continuous supply systems.
Financial support and participatory decision-making were proposed as solutions to speed up the rate of implementation, to keep up with population growth (hence demand increase) and guarantee the success of transition plans.
The Safe & SuRe intervention framework was used to assess resilience of the IWS systems during COVID-19.
Some participants indicated that a risk-based assessment of the system was carried out. Remote NRW measurement, pressure management, electronic billing and communications with users were mentioned among mitigation measures that were considered to improve operation efficiency, in preparation to respond to COVID-19 impacts.
Some participants suggested that plans were adequate, however indicated that if the COVID-19 pandemic was