Properties that a GIS must possess as the basis of a loss reduction system.
Mobile first design
The GIS must be fully available in the field, which means that it must be solved as a Web GIS with an interface adapted to work on the screen of a mobile device. The reason: losses are field work, without which maps are printed again. The offer for creation must also include web hosting (a public web address from which the GIS is loaded).
Central spatial database
It works with a spatial database, primarily POSTGIS (https://www.postgresql.org/) which is open source ( completely free and for commercial use ), extended with spatial queries, today practically a standard and easily connects to all other applications of today and tomorrow. Commercial databases do not offer anything better and are paid annually.
Connection to the water meter reading computer database
Necessary for water balance in DMA.
The data in the database is updated periodically as readings are taken, so a unique date needs to be determined for monthly consumption. To ensure that it is the same for each month, we take the 28th day of the month.
It should also be taken into account that some water meters are not read or are read more frequently, all of this needs to be resolved in the reading database with appropriate programming.
Connection to NUS (telemetry)
Some of the inputs to the DMA are not measured using ‘network’ meters but are measured in the telemetry system, so to make a DMA balance we need these measurements as well.
Therefore, the GIS must be connected to the telemetry computer database. This can be demanding because telemetry databases are different from the usual ones (they are fast, contain a large amount of data, the data is quickly moved to another, so-called, historical database, so they are more difficult to access)
Connection to network flow meters
Since they are located in shafts and depend on the GPRS signal, battery status and the operation of mechanical water meters, these meters have lower reliability in sending data.
For this reason, GIS must inform about alarm conditions and use statistics to supplement missing measurements for a certain time period. The time periods are month and year.
Spatial data
According to the accepted IWA method, ILI is calculated, the ratio of actual (measured) losses to unavoidable losses for each DMA (metering zone) in the water supply network and for the entire system.
The calculation periods are month and year.
This means that we must have input and output meters for entire water supply systems (one water service provider can have multiple systems) to produce an annual balance sheet as well as for each DMA.
Actual losses are the difference of the total amount of water that entered the DMA and the total amount delivered to consumers minus the amount of water that left the DMA to another part of the network. Flow meters are placed on the inputs and outputs of the DMA or data from telemetry is used.
Unavoidable losses are calculated as a function of several parameters: network length, number of house connections, total length of connection lines, average pressure in the system.
For this, we need to have a complete and accurate network record and, above all, the topology.
Before entering the reduction of losses, the Brižni waterworks recorded with GPS the entire network and connections: Ogulin, Senj, Delnice.
Main pipelines must be separated from distribution pipelines for a realistic calculation of the OR coefficient.
Malfunctions
The GIS should monitor hourly and daily balances of water entering the DMA and send alarms when there is a deviation from normal values. It should also indicate data on minimum nighttime consumption, the increase of which indicates the occurrence of a fault within the DMA.
Work on reducing losses is usually associated with repair of faults. This is wrong because failures are the result and the cause is poor maintenance or construction.
Status of similar GIS projects
The creation of a briefly described GIS system is very demanding. On a European scale, there are not many publicly available examples of described GIS projects. For this reason, it is necessary to first check how the offered program works with another utility company, and in addition, it is necessary to:
- Analyze the state of the existing GIS, primarily data
- The existing GIS is a Web GIS with great capabilities and comes in a large number of forms, which are easily created according to needs and are used by many municipal authorities: Delnice, Senj, Rovinj, Omiš, Brač, Dugo Selo, Istrian Water Protection System, Rab, VHPJO, NPKLM , ..
- The existing GIS has a version with the previously described features, which is in use in several waterworks and includes telemetry hydrants, devices against water theft
- Request a written IT description of the offered system
- Outline items:
- Specification of requirements for a software solution
- Specification and appearance of the program interface
- Creating a database schema
- Connecting to foreign databases and devices
- Changes to the programming code of existing applications for compatibility
- Development of program modules
- Connection to existing business software
- Implementation of developed software
- Checking the functionality of the developed software (verification) in real conditions
- Require system testing, IT systems are easily designed to be a ‘white lie’ and without any malicious intent on the part of the developer, simply contracting too much to build at once.
