By Engineers Peter Morris and Bernard Musarurwa
This document has been produced in response to the publicised call from the chairperson of the Environmental Management Committee, Councillor Kudzai Kadzombe, for independent engineers to help solve the water crisis.
Firstly we would like to correct some misconceptions in the article that was published in the press.
- Harare needs 1,200 Ml/day. Harare could only need this amount of water if there are massive losses. The 2012 National Census gave the population of Harare, Chitungwiza, Epworth, Ruwa and Norton as 2,123,122. If Morton Jaffray Works were delivering its full capacity of 614 million litres a day it would produce 190 litres per person per day. Even if the population has doubled since 2012 there would still be 145 litres per person per day. Despite this we know that large numbers of people have no water. For comparison, Cape Town uses 581 Ml/day. Bulawayo supplies all of its population and it is producing 150 Ml/day. Bulawayo has 30% of Harare’s population and if it were the size of Harare it would need only 488 Ml/day.
- Water in Harare’s dams has reached alarming levels. This is not the case. We tabulate below the dam data as published by ZINWA for July (the last available date on their web site). It will be seen that in July there was a significant amount of water still in the dams. Since abstraction has only been 300 Ml/day there is still a lot of water stored.
|Dam||Full capacity |
(millions of litre)
|Current capacity |
(millions of litre)
- We need Kunzvi and Musami Dams. We will need these dams because demand will grow. However with the state of water losses in the system and the poor financial situation (see below) no serious donor or PPP principal will consider funding these schemes. Kunzvi and Musami will not be viable until the management and financial problems in Harare Water are resolved. With a time line of 3 years to implement after funding has been found, Kunzvi and Musami will not address the current water shortage.
- We need Mazowe Dam. Mazowe full capacity is 39,350 Ml or 16% of Chivero. It is too small to make any difference, its water is committed to agriculture in the Mazowe Valley and in recent years it has run dry several times.
- Purchase of 14, 5000 litre bowsers will alleviate the problems. Assuming 4 trips per day these bowsers will be able to move 280,000 litres per day. Allowing 25 litres per person per day they will be able to serve 11,200 people. They will be useful to provide water to a small area while a burst pipe is repaired. They will not make a difference to the overall situation.
Turning to Harare’s real needs, the over-riding issue to be addressed is financial and managerial. The article reports monthly revenue of RTGS 15 million against RTGS 35 million in treatment costs. Production is only 300 Ml/day because there are no funds to purchase chemicals. Customers have not been billed since March. When customers were being billed, non-revenue water was 60% while recovery on billing was 40%. The effect of this is that for every 100 cubic metre produced at the treatment plants only 16% was being paid for. Lack of income to run the system is the main cause of the inability to supply water.
The most urgent need for the City is to generate income to the water account to enable the system to run.
Steps to do this include:
- Bill your customers. This need is urgent – without billing there will be no revenue. It is important that the billing be fair. Charging customers for 40 cubic metres when they have had not water for 14 years will only generate resentment and a reluctance to pay.
- Consider pre-paid metering for larger institutional, industrial and commercial customers. Prepaid meters are very expensive and the cost cannot be justified for domestic customers. For prepaid metering to work there has to be a significant investment in payment systems so that it is not difficult for the customer to pay. The initial chaos with ZETDC when prepaid electricity meters were introduced is a case in point.
- Sort out the customer data base. Harare has 3 times the number of people that Bulawayo has but it does not have as much as 3 times the number of customers.
- Ensure that customers pay their bills. Recovery on billing should be more than 90% not less than 50%. Cutting off non-payers has not been successful because of court challenges on the basis of right to water. A solution to this problem that has been very effective in Ethekwini is to install flow restrictors that provide the minimum to survive but no more.
- Ensure that everybody gets at least some water. Customers will not pay for product that they do not receive.
- The Minister of Local Government must allow a rate increase to enable Harare Water to keep up with escalating costs. The increase will be less than the increase in the inter-bank rate because wages and electricity have not so far increased.
- Engineering interventions are needed but it cannot be over-emphasised that unless the system can afford to pay for at least its running costs it will be impossible to meet its obligation to supply the residents of the city with water. Some engineering interventions are:
- Replace pressure reducing valves on feeds to areas that are supplied from high pressure mains. Doubling of pressure increases leakage by roughly 4 times. Pressure reduction is the most effective way to reduce leakage.
- Repair burst water pipes as quickly as possible. The plumbing teams must be given every support to enable them to do this.
- Make a start on replacement of old pipes in the network. There has been no network renewal for decades and many of the pipes are near or past their 40-year design life. This is an area where donor funding will be needed. However if the internal finances can be sorted out so that there is some money to pay for pipe renewal the investment will quickly be recouped. Reduction of losses reduces costs because water is saved that has cost money for chemicals and electricity for pumping. At the same time more water is made available to customers so revenue is increased.
- Address pollution of the water sources by untreated sewage. This involves not only the sewage treatment works – a brief smell of almost any stream in Harare reveals that it is polluted by spills of raw sewage from blocked sewers and broken down pump stations. The impact on water treatment costs will not be as big as has been claimed.
Polluted rain water runoff is a significant contributor to the pollution load to the dams so the anticipated 50% reduction in chemical costs is unlikely to be achieved. The 2011 Tariff Study showed that chemical costs were 28% of the total so even if chemical costs could be halved, cost to produce water would only be reduced by 14%. The need to reduce pollution of the lakes supplying Harare does not have only a financial justification. The quality of treated water is remarkably good by classical criteria but there is growing concern about new contaminants such as endocrine disruptors.
In summary, there is no quick and “innovative” technical solution to Harare’s problems. The causes and solutions are well known. Administrative and financial issues must be resolved to ensure that the system can at least cover its operation and maintenance costs. Without resolving these issues it is almost pointless to consider technical solutions.
The work that must be done is hard – it is neither easy nor glamorous – but it must be done.
Source: Engineers Peter Morris and Bernard Musarurwa