Prepaid Water Metering System

Utility Systems developed the first commercially available, STS approved, proven prepaid water metering system. The Utility Systems prepaid water metering system is not proprietary token or card-based but is an open architecture system complying with IEC standards (IEC 62055-41 and 62055-51) used in over 90 countries worldwide. Having an open architecture system means that water service providers that acquire such a system are not locked into and dependent on one supplier. They can also purchase metering products and implement vending systems from any other supplier whose products conform to the same standards. This ensures that prices remain competitive, and that suppliers are constantly challenged to provide the best and most cost-effective technology. The STS approach adopted by Utility Systems allows for multiple vending options through a wide variety of STS compliant vendors. The Utility Systems prepayment water metering system also incorporates a radio frequency and global system for mobile communications (GSM) based data and command transfer system. This enables two-way communication between the water service provider and the meter, a feature not available in most other prepaid water systems.


Water Management Device (WMD)

The Utility Systems WMD is the original water management device and is the primary product in the prepaid water metering system. The WMD contains an electronically controlled valve and microprocessor with embedded firmware that enables it, when connected to a pulse output water meter, to perform a number of smart metering functions in addition to those usually associated with a prepaid water metering system. Key functions and features:

  • Monitors and controls water consumption
  • Has a short-range radio used to communicate with the user interface unit (UIU), data collector and field service terminal
  • Logs and stores consumption data over an extended period
  • Stores cumulative month-end consumption data suitable to be used for billing purposes
  • Detects and warns of possible consumer-side leaks
  • Detects tampering
  • The WMD product is usually housed in a meter box assembly incorporating an incoming stopcock, a water meter, piping and the WMD.

The WMD’s primary function is to monitor and manage domestic water consumption. The water consumption is monitored directly from the pulse output of a conventional water meter via a fully electronic probe. This ensures high accuracy, reliability and long life. The WMD is also able to interface to standard reed switch and electronic pulse output sensors. The WMD can transmit data and receive commands by radio. This two-way communication ability provides the infrastructure for near real-time control over the consumer’s water supply. In addition to prepayment functionality, the WMD can also manage the customer’s water consumption to turn the water on and off at pre-determined times or restrict supply to a specific volume.

User interface unit (UIU) for in-home display and STS token entry:

The Utility Systems UIU is a remote display unit that is installed within the consumer’s home. The UIU:

  • Displays the meter reading as reflected by the WMD which is located outside the premises
  • Displays the remaining prepaid water and any additional water allocation available
  • Displays the WMD serial number which is needed when purchasing a token
  • Is the means to enter top up and credit token in a prepayment system
  • Provides various alarms including leak and tamper


Utility Systems can provide a standard set of reports which are updated and available immediately on-line. Further customised reports can be obtained by arrangement. The standard reports include:

  • Transactions by customer vending point
  • Sales summaries by day and month
  • Monthly management summary
  • Exception reports on low or non-existent purchasing patterns which could be an indication of theft

Prepayment or top-up credit vending:

Prepayment metering enables municipalities and other water service providers to give their customers the ability to purchase credit themselves, without having to read the meter and generate and send out a bill. This not only improves revenue collection but also reduces the costs associated with it. The Utility Systems WMD enables a water service provider to implement a prepayment metering system based on the STS Association standard, which regulates the manner in which a 20 digit token is issued. Benefits associated with the implementation of this STS prepayment system include:

  • The consumer having full control of their own specific water needs
  • A choice of non-proprietary vending infrastructure and options that could include:
  • A current STS electricity vending station, including XML-vend based vending platforms
  • An independent vendor
  • Internet-based vending
  • Points of sale
  • Cell phone/SMS-based vending
  • Banking hall based vending

Data collection:

The data collector is the second tier within the Utility Systems prepaid water metering or automated meter reading (AMR)/advanced metering infrastructure (AMI) system. The system can be scaled to suit most requirements, from a walk-by or drive-by to a fully-fledged automated, near real-time GSM-based implementation. Using a reliable radio link, the WMD transmits a pre-defined message via radio frequency and according to a pre-programmed schedule. The WMD message is then received by a data collector. The data collector can either be in the form of a fixed network or can be used in a periodic or random walk or drive-by network. The data collected within the network is then transferred via a secondary communication link to a server. This secondary communication link includes GSM and USB connectivity. The data collector will not only collect the data provided by the WMD but will also interact with the WMD and transfer relevant configuration parameters or commands. The interaction can be set to a single or a small selection of WMDs or broadcast to all WMDs within range.

User interface

The Utility Systems user interface has been developed with the intention of providing a simple interface between the municipality and our AMR/AMI system.

The data collected from the WMD can be downloaded directly from the data collector into a local database via a USB connection or into the server’s database through time-scheduled transmission via the built-in general packet radio service (GPRS) link.

The protocol and implementation allows for a wide variety of system configurations to be supported, ranging from localised gated communities, through to urban municipalities and even wide-spread rural areas.


  • Walk or drive-by data collection
  • Fixed network data collection and transmission
  • Leak and tamper detection
  • Comprehensive data on consumption
  • WMD and UIU split for convenience
  • Optional audible feedback on UIU
  • Supports programmable free daily allocation
  • Pressure tested to 16-bar operation with 24-bar protection
  • STS compliant encryption
  • Battery indicator
  • Numerical feedback keypad
  • Automated control of full-pressure (mains) or semi-pressure (tank) systems
  • Laptop interrogation, testing and re-programming in the field using low cost field service terminal (FST)
  • Optional AMR (automatic meter reading) by radio link
  • Supplied pre-programmed to order, but can be reprogrammed in the field or stores
  • Set daily or monthly limitation between 10 and 50,000 litres
  • 365 days hourly consumption logging
  • Incorporates tamper-proofing measures
  • Daily carry-over of unused allocation within a month
  • Indefinite daily carry-over
  • UIU has robust keypad
  • Multiple vendor support
  • Multi-vending infrastructure, utility banking hall, point of sale, SMS, web, scratch card etc.
  • Vending via third party: corner store café, petrol station, supermarket chain, etc.
  • Pressure range 0.5 bar to 16 bar
  • Battery life: 10-year (estimated dependent on use)

The Utility Systems prepaid water metering system is extremely versatile and capable of addressing a wide range of metering options. It is a tried and tested system with a very large proven deployment.

With our team of experienced product development engineers and years of metering experience, Utility Systems is confident of staying at the cutting edge of technology.