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<Proceedings of the International Symposium on Efficient Water Use in Urban Areas - Innovative Ways of Finding Water for Cities -> Session 5: Leakage Control and the Reduction of Unaccounted-for Water Advantages of Leakage Control
and the Reduction José A. Hueb Introduction The provision of adequate and safe drinking water supplies and the availability of appropriate wastewater facilities form a basis to improve the health and the standards of living of the developing world populations. These benefits will be accrued when the installed systems operate continuously and reliably, to the extent of their capacity and in agreement with acceptable levels of services quality. In a number of cities of the developing world, more than 25% of the water produced is lost before reaching the consumers, with some drinking-water supply networks losing more than 50% of the total water produced. Water supply networks in several developing countries are constructed predominantly with poor quality asbestos-cement, plastic (PVC, HDP), concrete or steel. Most industries have metered water consumption whereas this is generally not the case for domestic consumption. The technological features of water and wastewater treatment plants in developing nations do not differ substantively from those in industrialized cities. However, there are still serious difficulties with regard to the lack of spare parts and technical assistance and local skills vis-à-vis imported equipment or installations, specially electronic instrumentation. The water supply systems frequently function intermittently because of deficient operation, neglected maintenance and high levels of leakage. It is not unusual that the water distributed by leaking pipelines of the distribution network is contaminated through wastewater from defective sewers. Although many factors contribute to the situation described above, the greatest impact stems from a lack of effective management and lack of clearly defined objectives and policies and where institutional, managerial and operational adjustments would be particularly crucial to making the most of existing facilities. Such adjustments, aimed particularly at reducing the unaccounted-for water to acceptable levels, should be viewed as a pre-condition for implementing new projects dealing with rehabilitation, replacement or expansion of services. Efforts are being made by various international institutions, including the World Health Organization (WHO) to promote better management practices and improved operation and maintenance as a strategy to make the most of existing water supply and sanitation systems and to reduce unaccounted-for water. In order to make these efforts more effective, a working group on Operation and Maintenance was established by WHO, under the framework of the Water Supply and Sanitation Collaborative Council, whose major aim is to promote and support action on this important issue. This Group has produced various useful tools (guidelines, manuals, training packages and other information materials) dealing with most of the issues affecting sector performance and unaccounted-for water. The approach for reducing unaccounted for water includes a set of programmes and activities aimed at the optimization of water supply and sanitation facilities through improved operation and maintenance and sound management practices. These programmes are not confined to the technology aspects of the problem (leak detection, etc). They also tackle priority factors related to the causes of unaccounted-for water including institutional and organizational aspects, financial constraints, supplies, transport, information systems, human resources, etc. The establishment of a process conducive to improved efficiency and effectiveness and adequate institutional and managerial adjustments aimed at the proper carrying out of water supply and sanitation services and reduction of unaccounted-for water, requires substantial changes in the managerial culture of the water agencies. The required action should be tackled in an integrated way with a view to orienting the formulation and implementation of multidisciplinary programmes intended for overcoming the identified problems and constraints. Such programmes and activities should be prioritized, scheduled and implemented as a conjunct of interrelated and interdependent action in which cost-effectiveness should be a major concern. For instance, where the water and sewerage tariffs are not realistic and the consumers' registering system is not effective, a programme to overcome the latter constraints should receive priority because this would be an important factor contributing to the feasibility of the overall programme. Sector Constraints Many reasons have been identified as contributing to, or causing poor services and high levels of unaccounted-for water. These range from poor organizational structures in the responsible agency, lack of spare parts, inappropriate technology, lack of trained staff, tied aid, absence of career opportunities, insufficient funds, inadequate legal framework problems, lack of motivation by sector personnel, non-involvement of the users, the low profile of actions addressing optimization of services including leakage control, inadequate tariff and collection systems and negative political interference. These causes tend to be interrelated and intertwined. The Operation and Maintenance Working Group of Water Supply and Sanitation Systems (OMWG) identified the following key issues contributing to poor performance of water supply facilities: Inadequate Data There is an overall lack of data regarding the performance of the water supply and sanitation agencies. Precise, accurate data on the systems which are not performing properly are needed, together with information on the main reasons why. Detailed figures are also necessary to determine how much it costs to undertake an adequate unaccounted-for water programme for different types of facilities. Data are also required on the rates of breakdown of different systems such as pumping stations, pipelines in distribution networks, treatment plants, etc. Crucial indicators such as unaccounted-for water and its distinct elements are frequently unavailable or are inaccurate. Until this information is forthcoming it will not be possible to accurately assess the performance of the water systems and compute the financial losses due to poor operation and maintenance. These exact financial data are urgently needed to demonstrate to decision makers the advisability of implementing good programmes addressing the reduction of unaccounted-for water and leakage to acceptable levels. Insufficient and Inefficient Use of Funds Insufficient funding has been identified as a major contributor to poor operation and maintenance performance and high levels of unaccounted-for water. This lack of funds hampers the operating and maintaining of water supply facilities as money is not available to buy spare parts, properly train staff and provide competitive salaries to attract high calibre personnel. External support agencies have traditionally been reluctant to finance operation and maintenance activities while national governments have often given it a low priority. National governments are frequently stressed for cash, especially hard currency which is needed to pay for spare parts and the water supply agencies usually lose out to other, judged more important higher profile sectors. The users are a potential source of finance for water supply systems. They are often unable or unwilling to pay. Usually it is that they are unwilling to pay rather than unable to. Evidence is mounting that even in the poorest and most underprivileged segments of the community people are willing to pay for a reliable, adequate supply of clean water but unwilling to be charged for an unreliable and unsatisfactory service. It is a vicious cycle. As the service level drops due to high unaccounted-for water and high leakage levels the users withhold support and become less willing to pay which further constrains operation and maintenance activities. Sometimes it is the inefficient use of funds rather than a lack of money which contributes to poor performance. The poor management of facilities results in the squandering of resources which then reduces the viability of the water supply system. Those responsible for managing water supply facilities need to look carefully at their operations to ensure that they are operating efficiently. Too often many unskilled staff and poor logistical and organizational structures are common problems. Losses of revenue from unaccounted-for water are a problem for most systems. It is difficult to define what is an acceptable level for unaccounted for water. A figure of 25% may be appropriate as a first target for an agency working at unaccounted for water levels of 50%, but significantly lower levels can and should be achieved. What is an acceptable level of unaccounted for water has to be determined on the basis of local conditions, but true wastage should not be significantly above 10% once illegal connections, free supplies, and leakage are reduced to acceptable levels and adequate metering, billing and collection procedures are maintained. High rates of unaccounted-for water, whether they are caused by illegal connections, leakage, free water supply, or the result of inadequate commercial operations, result in significant financial losses and poor service performance. Management of Water Supply Systems The water supply and sanitation systems will perform poorly if they are not managed efficiently and well. Typical management-problems include:
The inefficient organization of many water supply agencies is a serious
deficiency. If the organizational structure does not promote and allow
efficient use of existing resources then the overall management will
function poorly. The absence of transparent management and accountability to the users is another major issue. Often the users are not involved in the water supply agency and there is no feedback from the consumers to the management of the agency. This is particularly acute in government owned and operated agencies which tend to be bureaucratic. This non-involvement of the users in the management of the agency results in stress and in some cases the development of a confrontational relationship between the agency and the consumers. Studies of well run water supply agencies have shown that good customer relations and a sense of management responsibility to the users are common denominations in these organizations, contributing to their overall success. Inappropriate System Design No matter how good the management of a water supply facility is, if it is not well designed technically, it will operate inefficiently. Many water supply facilities have been badly designed, poorly constructed and use technologies which are inappropriate. When a facility is improperly designed and constructed it cannot perform satisfactorily. There are many reasons for poor systems design. In some instances consultants are chosen by ESAs who are not familiar with suitable technologies for use in the developing world and specify equipment and/or designs which are inappropriate. In other cases, there may be political interference to promote one particular pipe material or supplier and they may not represent the optimum choice for that particular situation. A lack of communication between the system designer and the operators of the system is a further drawback. The operators of the system need to be familiar with, approve of and be comfortable with the technology. In addition there needs to be a continuous feedback of information from the operators to the designers to pinpoint problems with the design and suggest remedial measures. Poor quality pipes and valves used in distribution systems or pipes installed without the appropriate technical requirements will result in serious leakage problems during the whole life span of the project.
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