Technical description

Rapid diagnostic assessment of the distribution systems based on recently developed component based software.

Details

Halcrow was appointed by the Water and Sanitation Programme – South Asia of the World Bank to assist three Indian cities in their attempts to implement continuous supplies and carry out rapid diagnostic assessments, utilising Burst and Background Estimate (BABE) software.

This model identified areas of high non-revenue water in the distribution system. From this our distribution specialist was able to advise the local engineering staff as to the most appropriate course of action to reduce NRW and increase the likelihood of continuous supplies.

Discontinuous supply gives rise to difficulties in the service and it's management, including serious risk to health from ingress of contaminating groundwater and inability to practice efficient supply/demand management. The cities of Indore, Nashik and Ramagundam have taken steps to introduce continuous water supplies.

The city of Indore has some unique issues regarding water resources. Indore is resource deficient with it's main supply pumped from 70km against a static head of 550m. The unit cost for water in Indore is, therefore, very high.

With few exceptions, users of piped water distribution systems in Indian cities receive water on an intermittent basis. This practice has developed as a response to a combination of circumstances, including rapid population growth, inadequate levels of water changes, insufficient utility revenues to repair, maintain and replace pipelines, property connections and related devices, intermittent and poor electrical supply and lack of experienced personnel.

When intermittent supply starts being practiced, the quality of service progressively deteriorates in a downward spiral as customers withhold payments for the poor services. Reducing revenues makes it increasingly difficult for the provider to reverse the situation.

As intermittent supplies become the common practice, service providers and customers adapt their systems and connections to the situation. This means that operating staff are fully engaged rotationally switching supplies. Customers act to maximise individual supply and system improvements do not cover continuous supply. Engineers also lack suitable experience of continuous supply, erratic electricity supply contributes to supply problems and there is insufficient incentive to moderate change.