Zvishavane Town Council (ZTC) recently sent an SOS to UCAZ for technical assistance under the UCAZ-GIZ partnership programme regarding low water pressure challenges that residents were experiencing in one of ZTC’s suburbs, Eastlea. Council could not establish the reason for the low pressure hence the decision to request for assistance. GIZ and UCAZ have signed a Memorandum of Understanding (MoU) in 2017 under which GIZ provides technical support to both the UCAZ secretariat and the member local authorities. Under the partnership UCAZ and GIZ, a non-revenue water conference was held in 2017 which was attended by representatives from all the 32 urban local authorities.

Ultrasonic flow meter – used to measure different pipe sizes and show water that is passing through a particular point at every second, minute or hour. It is used on main water lines by clamping it on to the main line. The information can be uploaded to a computer and will show all the data of high and low movement. The equipment can be installed for 24 hours in order to analyse different demands per each period.

UCAZ and GIZ sent a technical team, with the primary objective of assisting ZTC in addressing the water delivery challenges. The team carried out investigations on water flow and pressure for a period of one week, from the 6th – 10th of May 2019. The technical team also carried out an initial assessment of the water network in the form of drawings and physical checks and financial database through the Promun system. The purpose was to have an overview of the whole water system and customer database to understand how the consumers were behaving, water meter functionality, water supply patterns and system pressures.

It was noted that ZTC did not have a GIS database. Several other issues were noted including factors that impact on water supply to Eastlea. Other issues were related to the whole network.

  • To understand the problem in Eastlea, several factors had to be analysed which include:
  • Water supply per person per day
  • Consumption per person per day
  • Water pressure
  • Number of households
  • Population density

From the investigations carried out during that period, the following were the major findings:

i) An estimated 89% of water meters in Eastlea alone are non-functional and are billed an estimated consumption of 40m3 per month which is allocated to domestic low-density accounts. Non-functional meters pose the biggest problem to any water network:

  • In Eastlea alone, ZTC is losing potential revenue of more than $21 577 per month or $258 924 annually
  • Non-functional meters promote water abuse by the consumers as they tend to use more than what they are billed per month. This is a fixed charge based on an estimate of 40m3 per month. Consumers are then in turn under or over-charged for water consumed per month because the actual consumption is unknown.
  • The abuse of water by the few customers that receive it leads to a significant drop in water volume and pressure in the network, which affects those who are at higher elevation.

The team observed that non-functional meters were common throughout Zvishavane. Dadaya High School is one of the biggest water consumers. The school is charged on average 500m3 per month according to the billing database.

However, after physical measurements Dadaya High School’s actual consumption is 12 108m3 per month translating to losses of about $6 054 per month or $72 648 annually of potential revenue for ZTC just from this one consumer.

ii) Based on physical measurements in Eastlea, there is significantly low pressure in the network of 0.1bar from an expected 5.0bar and a very low average flow rate of 20m3 per hour for an area with an estimated population of 2 536 people. These low pressure and flow rates combined with the other factors described above lead to:

  • Insufficient supply of water per person in the Eastlea area
  • Low pressure resulting in water not being able to reach households in the higher areas

iii) At the time of interventions, there was insufficient data in the form of drawings showing the exact pipe network within the system. The basic knowledge from the ZTC engineering team suggested that many interconnections within the system were done but not documented. Overtime that knowledge has been lost. Without the drawings, the exact connections in the network are unknown. This makes it difficult to isolate an area to carry out correct measurements in the specified zone as all the water entering or exiting the zone should be accounted for.

A full report of the GIZ technical mission to Zvishavane is available to UCAZ members.