Spread over 58 square km, Vijayawada is the third-largest city in Andhra Pradesh, with a population of over 1 million. The Vijayawada Municipal Corporation (VMC) is responsible for the provision of water services, construction and maintenance of roads as well as the underground drainage system, solid waste management, etc. It supplies over 45 million gallons per day (mgd) of treated water to its citizens at an average per capita of 150 litres per day.
The municipal corporation introduced a supervisory control and data acquisition (SCADA) system in 2010 to improve the operations and management efficiency of the water supply network. Although the project was successfully implemented, it ran into technical issues and has not been operational since 2014, leading to difficulties in managing the supply channel.
In light of these difficulties, VMC has decided to revive the SCADA system. It has awarded the project to Efftronics Systems and will involve a cost of around Rs 95 million. The project will entail improving and maintaining the existing system.
Background
While the corporation has been successful in providing treated water to all, it has not been able to achieve 100 per cent metering of all house service connections. At present, of the 80,000 house service connections, only 7,143 are metered, which constitutes 9 per cent of the total service connections.
In addition, VMC faces the issue of unaccounted-for water. The corporation supplies nearly 45 mgd of water through 60 reservoirs. However, about 30 per cent of the total supply is wasted due to overflow and leakages.
The water distribution network has other issues such as an obsolete and faulty pipeline network, resulting in high operating costs, intermittent water supply, low pressure leading to back siphoning and contamination, high physical losses ranging from 25 per cent to 50 per cent, inadequate personnel training, insufficient data availability, and lack of performance evaluation and monitoring.
VMC has taken a number of IT initiatives to plug the problems related to water supply in the city. These include several e-governance initiatives, and the adoption of an online grievance redressal system, management information system and SCADA system.
SCADA system
VMC adopted a SCADA system in 2010 under the Jawaharlal Nehru National Urban Renewable Mission of the Ministry of Urban Development. The total cost of the project was about Rs 540 million and the execution period was four years – one year for implementation and three years for maintenance.
The focus of the project was database management. The adoption of the SCADA system established a comprehensive online data and information base with tested software and equipment. This initiative helped the corporation in dealing with leakages in distribution pipelines, the high proportion of unaccounted-for water, irregular supply of water and overflows of treated water from service reservoirs.
The system involved data acquisition at various stages of procurement, treatment and distribution. The various field parameters assessed were flow level, water level and chlorine level. These parameters helped in monitoring the quality and quantity of water supplied in the distribution network. This ensured better control over field operations and systematic documentation of maintenance works.
The parameters were measured using a flow meter, a level meter and a chlorine analyser. This equipment served the following purposes:
- Flow meter: It worked on the magnetic field principle and collected information on the outlet flow rate at the plant, as well as the inlet and outlet flow rate at the reservoir. In addition, it measured flow rates at junction points to locate unaccounted-for water sources.
- Level meters: These worked on the ultrasonic principle and gathered information on the depth of the water in the reservoirs as well as in the sump.
- Chlorine analyser: Using the DPD method, the analyser monitored the amount of free chlorine residual at the plant outlet, the reservoir inlet and the reservoir outlet.
Moreover, an intelligent electronic device (IED) was installed at each plant and given a unique identification number. This device worked with the help of a GSM modem. After the information was collected separately by the flow meter, the level meter and the chlorine analyser, the IED assembled the information at one place. This assembled information was then transmitted to the front end processor (FEP) that provided control through digital outputs.
The FEP had as many modems as the number of plants and these modems had the same number as that given to the mode of an IED. This equipped the FEPs with information regarding the water position across all plants. A full handshaking mechanism was implemented between the IED at the reservoir and the FEP at the central monitoring unit (CMU) to avoid data losses under any circumstances.
The FEP provided the information to the central monitoring unit for processing the data and generating the output.
The CMU helped in sequencing the data and stored a large amount of data for historical trends. Apart from this, it generated various reports and graphs, and provided centralised monitoring, which assisted in supervisory control from a central place.
The data so collected was sent to the associated circle offices to ensure better control over water treatment and distribution. For example, the information provided by the CMU helped the water engineer determine whether sufficient water had been supplied to a reservoir. This aided in rationalising the water supply by changing the supply plans. In addition, this system helped undertake a complete analysis of the water supply network across the city. By monitoring the quantity and quality of water, VMC could enhance its service delivery and reduce losses in supply.
This system functioned efficiently until 2014, after which it started facing various technical problems. Due to the lack of funds, the corporation could not undertake maintenance work and thus, the system was abandoned. However, of late, the corporation has started receiving complaints regarding irregular, polluted and insufficient water supply. Moreover, water is wasted due to overflows while it is pumped from the head water work to the elevated surface reservoirs and boosters in the city. To address these issues, VMC has decided to improve and maintain the existing SCADA system, and resolve all the technical problems.
Moreover, VMC has initiated measures for the installation of water meters at all the 60 reservoirs in the city to plug leakages in the distribution pipelines and analyse the quantitative parameters associated with the supply from each reservoir.
Conclusion
The adoption of the SCADA system was a prudent decision by VMC, which enhanced its service delivery and enabled it to achieve universal coverage in water supply. By targeting the efficient utilisation of the existing capacity, regular and treated water supply was provided to the city for a long time. VMC’s initiatives were recognised by many agencies. It won the National Urban Water Award for 2009 and the CRISIL Best Practices Award for the Siti e-Governance Project. It was also the first corporation in the state to receive ISO 9001 certification for quality management system.
Unfortunately, the system’s operations could not be continued after 2014 due to technical failures and financial constraints. This led to a deterioration in service delivery.
VMC’s decision to restore the existing system will serve the dual purpose of enhancing service delivery and introducing further efficiency in the operations and management of the water supply network.