Introduction

Water losses from municipal reticulation systems are becoming a serious problem throughout the world and particularly in developing countries where lack of funds often results in poor maintenance of the water infrastructure. In some areas, the water losses are now estimated to be higher than the actual legitimate water use and the situation is gradually deteriorating to such an extent that intermittent supply is now the norm rather than the exception in some parts of the world.

The International Water Association has identified water loss from municipal systems as one of the most important issues facing a world where the ever increasing population is placing additional strain on systems which are already failing to meet the current demands. In response to these problems, the Water Losses Specialist Group was formed and has emerged as one of the most active and significant groups within the IWA. Its key function is to share the knowledge from specialists throughout the world to assist water suppliers to manage and reduce their water losses. Through the efforts of the group, many new and innovative techniques have been developed to measure, monitor and analyse water losses from municipal water supply systems. A standard water balance has been developed which is now widely accepted worldwide and enables water suppliers to quantify the magnitude of their water losses in a standard and pragmatic approach after which they can select the most appropriate interventions for a specific area. No "one-size fits all" solution is appropriate when trying to deal with water losses and it is important to understand that each area has its own set of problems, some of which may be common to other areas and some of which may be unique to a specific region. It is therefore necessary to identify the key problems and to implement the appropriate interventions.

This book provides a basic overview of the key issues frequently experienced by water supply managers in both developing and developed countries. It is designed to assist water supply managers to understand the problems experienced in their own systems and provides advice on how the problems can be addressed through examples and practical case studies. The book is non-academic and is aimed at providing information and advice in a practical and easy to understand manner. The book is basically a collection of case studies and practical experience from numerous water loss specialists who have worked around the world and have experienced both 'best practice' and the opposite extreme. It is hoped that by providing such examples and case studies, water supply managers and those employed to assist them, can benefit from both the successes and failures discussed in the book.

1.1 THE TECHNOLOGY MATRICES

The choice of a particular leak detection/location technique and technology depends on the operating conditions and construction material of the pipeline in question. To assist in making this determination, four different matrices have been developed.

(1) Mains fittings only – high pressure

• For leakage detection on mains fittings only (no house connections) with pressures greater than 10 m head or 15 psi. Fittings are at a minimum distance of 200 m apart and maximum 500 m

(2) Mains fittings only – low pressure

• For leakage detection on mains fittings only (no house connections) with pressures less than 10 m head or 15 psi. Fittings are at a minimum distance of 200 m apart and maximum 500 m

(3) Domestic and mains fittings – high pressure

• For leakage detection on all property and mains fittings with pressures greater than 10 m head or 15 psi. Fittings are at a minimum distance of 10 m apart and maximum 50 m

(4) Domestic and mains fittings – low pressure

• For leakage detection on all property and mains fittings with pressures less than 10 m head or 15 psi. Fittings are at a minimum distance of 10 m apart and maximum 50 m

The matrices consider the following pipeline materials:

• Metallic

* Includes steel, ductile iron and other ferrous materials

• Concrete

* Includes reinforced concrete, pre-stressed concrete pipe (PCP)

• Asbestos cement

• Glass-reinforced plastic (GRP)

• Polyvinyl chloride (PVC)

• Polyethylene

* MDPE medium density poly ethylene

* HDPE high density poly ethylene

The technologies available are discussed in more detail later in this document. The equipment has been placed in the selected categories where it is reliably successful. The equipment may sometimes be successful in other categories but not reliably so.

Note that new equipment is continuously being developed: these matrices only take into account equipment that was available during the preparation of the matrices (up to December 2012).

1.1.1 Main pipelines only – high pressure

This matrix is for leakage detection on mains fittings only (no house connections) with pressures greater than 10 m head or 15 psi. Fittings are at a minimum distance of 200 m apart and maximum 500 m.

1.1.2 Main pipelines only – low pressure

This matrix is for leakage detection on mains fittings only (no house connections) with pressures less than 10 m head or 15 psi. Fittings are at a minimum distance of 200 m apart and maximum 500 m.

1.1.3 Domestic and mains fittings – high pressure

This matrix is for leakage detection on all property and mains fittings with pressures greater than 10 m head or 15 psi. Fittings are at a minimum distance of 10 m apart and maximum 50 m.

1.1.4 Domestic and mains fittings – low pressure

This matrix is for leakage detection on all property and mains fittings with pressures less than 10 m head or 15 psi. Fittings are at a minimum distance of 10 m apart and maximum 50...