EDITORIAL COMMENT : Recommissioning of Lake Manyame tunnel way to go 

Source: EDITORIAL COMMENT : Recommissioning of Lake Manyame tunnel way to go | The Herald December 24, 2019

EDITORIAL COMMENT : Recommissioning of Lake Manyame tunnel way to goLake Manyame

The recommissioning of the tunnel bored in the 1980s to bring raw water from Lake Manyame to Harare’s Morton Jaffray Waterworks has the immediate benefit of assuring the city’s raw water supplies and of cutting treatment costs by providing a good flow of much cleaner water to mix with the polluted filth of Lake Chivero.

The move shows that swift action is possible to get essential services operating. The tunnel fell out of use a decade ago when lift pumps at the Morton Jaffray end failed and with that failure the rest of the infrastructure was not maintained.

Lake Manyame is downstream of Morton Jaffray so while water flows to the waterworks, it then has to be pumped up from the tunnel end for treatment.

A month ago, President Mnangagwa, after a detailed technical briefing, ordered the recommissioning of the tunnel and the urgent repairs were finally done.

But, by itself, the recommiss-ioning of the tunnel will not solve the water problems of the Greater Harare area. The waterworks themselves need further repairs, which are now being done, to improve the supply of treated water. At the same time, the large pump complex at Warren Control, the main terminus of the double pipeline from Morton Jaffray to the city, is also being repaired.

This will at least ensure more water to the main population centres in the western and south-western suburbs, but other repairs will be needed to get water much further into the swathe of dry suburbs to the north and east of the city centre. And that is just the short-term.

To get adequate supplies, the treatment works need to be expanded. The last expansion, which doubled capacity, was done almost 30 years ago and since then the population of the city and its satellite municipalities and towns has continued to grow steadily at a fair clip.

The result of the population increase, and the increase in business and industry, along with deteriorating treatment and distribution capacity has seen ever more areas cut off from municipal water and intermittent supplies in areas that could be more easily served.

The Presidential intervention was welcome. But it should not have been needed. City engineers know exactly what they need to get the system working. What was lacking was political will and the money. The President provided both once he was convinced the technical solutions existed.

But Harare City Council, instead of wringing its hands, should have provided both a long time ago.

Simply collecting money owed by residents and water users would have provided most the of the required cash and made its approaches to central Government to get the rest a lot easier.

Even fulfilling the desire to have a high proportion of less polluted water being treated is only short term. Once Manyame River comes down in flood again, it will fill the smaller Harava and Seke Dams, and so allow the smaller Prince Edward waterworks to reopen, and then start filling Lake Chivero. But when Lake Chivero starts spilling, the filth in that lake will be flushed into Lake Manyame. Admittedly, the larger and shallower Lake Manyame will allow more sunlight and air to help clean the water, but we should not be using our supply dams to clean out filth. We should be doing that properly at the sewage treatment plants.

So, the long-term solution is to stop polluting the Manyame River dams. And that requires a lot of long-neglected and long deferred work on sewage treatment.

The giant Firle works in the Mukuvisi valley and Crowborough works in the Marimba valley need to be refurbished and dramatically expanded. The technology is first class, but neither maintained nor expanded for 30 years.

The long-planned modern treatment works for the Ruwa River valley, serving far eastern Harare and Ruwa town, needs to be built. Chitungwiza’s Nyatsime works needs to be scrapped and replaced by a large modern works.

The time has now come for the fifth modern treatment works at the site selected more than 30 years ago in the Gwebi River Valley to serve the far north and north-west of Harare, Mount Hampden and “the new city” around the new Parliamentary complex. Gwebi River eventually flows directly into Lake Manyame, so again the effluent needs to be pure.

Those who keep discussing planned new dams to the north of Harare and the south of Chitungwiza need to remember that while needed, they will not replace Morton Jaffray and the Manyame River dams.

They will make it easier to supply the high ground to the north and east of Harare and to the east of Chitungwiza, but even with these two new schemes, and the reopening of the Prince Edward works, over half the metropolitan area’s treated water will still have to come from Morton Jaffray fed with raw water from lakes Chivero and Manyame.

So we still need to rebuild and extend that water treatment works, clean the dams and then keep them clean. The water and sewage engineering was worked out in the 1980s.

If Harare wants to fulfil its dream of being a first class city, and if Zimbabwe is to meet its Vision 2030 goals of middle income status, then those engineering plans need to be turned into concrete and steel now. We know what to do. All we have to do is do it.