IT is becoming increasingly obvious that Zimbabwe needs to capture and use or store almost every drop of rain that falls on the country in this era of climate change to combat the ever more frequent droughts and ensure that there is enough water for the growing industries of our cities.
Very large sums have already been invested over many decades in building dams and pipelines, and the Second Republic has devoted substantial resources over the past six years to accelerating the dam building and irrigation programmes, using national resources freed up by the strong discipline it has exerted in the Budget process and Government spending.
Normally, we would have been able to extend these programmes, or at least some of them that produce income, through access to global development finance, but with the Western sanctions still in force against Zimbabwe, this is difficult.
But Zimbabwe has now been tapping other funds, seeking investment partners where appropriate to come in and speed up the development of the crucial infrastructure to manage our water supplies and use them for maximum benefit.
This culminated in July this year with the Zimbabwe Irrigation Investment Conference in Harare.
Commitments of more than US$1,5 billion have now been made, allowing a range of work to be either finished earlier than expected or to be started and completed earlier, thus doubling irrigation as quickly as possible and making sure there is enough commissioned irrigation to grow all our grain for self-sufficiency in summer and winter.
The efforts by the Second Republic to extend irrigations schemes, rehabilitate those that were not functioning, and commission new schemes has already seen irrigated land extend to 217 000 hectares.
This is more than 60 percent of the 350 000ha required to grow all our food, with both summer and winter irrigation so the country is climate-proofed against drought, at least on a national scale.
The investments now at least committed to the memorandum of understanding level will see irrigation reach 495 000ha, enough to not just produce our essential foods, but also stockfeeds and export products, building our national wealth as well as national food security and producing a decent income for ever more of our farmers.
The investments are also designed to store water for our cities and bring that to the factories, offices and their workers with the two largest urban complexes in Harare Metropolitan and Bulawayo Metropolitan needing more assured water supplies as soon as possible, much of it needing to be brought by ever-longer pipelines.
Urban water is ideal for commercially-orientated investment, and the pipelines from Gwayi-Shangani to Bulawayo and across the whole of Goromonzi district from Kunzvi to Harare will need substantial investment.
With the bulk of urban and industrial water costs coming from treatment and the distribution network from the treatment works, higher priced raw water including the costs of being pumped through a long pipeline is not a critical factor and will be a lot cheaper than water delivered by road tanker.
Some of the electricity needed for pumping at the larger schemes is likely to come from the modest hydro-schemes being installed or planned, 5MW to 15MW. The Zimbabwe National Water Authority, Zinwa, has made it clear that it will not be able to release water just for power generation, but is more than happy that water released for irrigation, mining, industrial and urban requirements can flow through the power station as it leaves the dam.
As we expand our irrigation, we need to make sure that we use our water extremely efficiently, since the dams will fill from the run-off, and in a drought year there is less rain and quite a lot less runoff.
Water can be stored, at least in larger dams, for two or three years, and sometimes even more, with some Lowveld dams even designed to fill completely from a cyclone every decade and just be topped up with annual rainfall.
We have already been upgrading the technology used in irrigation with flood irrigation, for example, seen as very inefficient with high levels of waste and far more now being done through overhead irrigation with carefully calculated amounts of water discharged.
Now with the village business units being run off the village boreholes, we are installing drip irrigation, well-known to be the most efficient and allowing the maximum amount of land to be irrigated from a fixed water source.
We would like to encourage more such irrigation, especially when energy needs can be met by solar panels and the software that measures our precise quantities of water is becoming ever more sophisticated but ever easier to use.
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This is important in summer irrigation where even in a very bad drought year some rain falls everywhere in Zimbabwe and what farmers need is supplementary irrigation, making up the gap between what they get from the sky and what they need to pump.
Even in the best rainfall years, some supplementary irrigation is useful, at least to start a crop earlier and make sure there are no gaps in the growing season. And in a drought year more than half the water on a field may have to be pumped in.
There are irrigation costs. Power is needed to run the pumps, hence Zesa ringfencing supplies for farmers, and while solar and mini-hydro may take over much of that load, there is still operating and maintenance costs.
Zinwa itself charges for water, to at least maintain the infrastructure as we have learned of the dangers of not doing so.
So the more efficiently a farmer uses irrigation water the lower the production costs, and the more security the farmer has that the water supplies available will last through a double drought before the dam is fully refilled.
