Cape Town races to beat Day Zero

The city could run out of wa­ter in March and is rush­ing to get mea­sures such as de­sali­na­tion in place

Mail & Guardian - - Business - Lisa Steyn

The R321 cuts straight through the cen­tre of the Thee­wa­ter­skloof Dam in Cale­don. Be­fore you ap­proach the bridge that tra­verses the wa­ter, the scene looks more like the Namib Desert than it does a dam. Dry white sand, kicked up by the Cape winds, fills the air. Be­low, dunes em­brace ashen and dead tree trunks.

A short drive on is the Thee­wa­ter­skloof Sports Club, which is eerily quiet. Pic­nick­ing and swim­ming are per­mit­ted, but boats may no longer be launched into the wa­ter — un­der­stand­ably so: it is bone dry at the jetty and the rus­set wa­ter is now some dis­tance away.

This dam is at the cen­tre of the Cape wa­ter cri­sis. It is the largest feeder of drink­able wa­ter to the res­i­dents of Cape Town.

It is also the emp­ti­est. With a 480-bil­lion-litre (or 480 000-me­gal­itre) ca­pac­ity, Thee­wa­ter­skloof amounts to 53% of all dam-wa­ter stor­age for the city. But at 27% full, it is at the low­est level of all the dams. This time last year, it was at 51% of its ca­pac­ity. The year be­fore that, it was at 74%.

Over­all, the City of Cape Town’s dam lev­els this week to­talled 38.2% — keep­ing in mind that the last 10% of wa­ter con­tains sludge and or­ganic mat­ter and is not us­able.

Cape Town is ex­pe­ri­enc­ing its worst drought since 1904, and the next rainy sea­son for the re­gion is sev­eral months away.

The day the dams run dry, dubbed Day Zero, is ex­pected to ar­rive in March next year. In the run-up to that mo­ment, con­sump­tion is likely to be as low as it will go — 680-mil­lion litres a day, against a tar­get of 500-mil­lion litres. It’s also im­prob­a­ble that leaks in the wa­ter in­fra­struc­ture will be im­proved much fur­ther. (See “Wag­ing war on leaks won’t win Mother City’s wa­ter bat­tle”.)

The task now is to find other wa­ter sources be­fore the taps run dry.

The city is pur­su­ing sev­eral op­tions but, be­cause of its prox­im­ity to the sea, de­sali­na­tion is key to mit­i­gat­ing the cri­sis. But the process is al­ready in­cur­ring de­lays at a time when they can be ill af­forded.

Ten­ders put out for small-scale tem­po­rary de­sali­na­tion plants re­ceived non­re­spon­sive bids and have had to be read­ver­tised.

De­sali­na­tion ex­perts say plants that will ful­fil the city’s needs take at least six months to get go­ing. In Au­gust, Cape Town mayor Pa­tri­cia de Lille said 500-mil­lion litres a day — the tar­geted wa­ter con­sump­tion level for the city — would be pro­duced with new tech­nol­ogy, in­clud­ing de­sali­na­tion, wa­ter re­use and ex­tract­ing ground­wa­ter from aquifers.

“Un­for­tu­nately, there are no quick so­lu­tions. There are no plants wait­ing around to be de­ployed,” said Chris Bray­brooke, the gen­eral man­ager of Ve­o­lia Wa­ter So­lu­tions and Tech­nolo­gies.

Ve­o­lia has built sev­eral de­sali­na­tion plants in South Africa, in­clud­ing the coun­try’s largest in Mos­sel Bay. “Some­thing like what we built in Mos­sel Bay would take two years to be de­ployed,” he said.

Cape Town had been ex­em­plary in its day-to-day man­age­ment of the wa­ter sys­tem, he said, but de­sali­na­tion projects take time and “ide­ally” the ten­der should have gone out six or nine months ago.

The Mos­sel Bay plant was built in re­sponse to a 2010 drought and was up and run­ning in 2011. It can pro­duce 10-mil­lion litres of drink­able wa­ter a day. But, like many de­sali­na­tion plants that are built in re­sponse to a cri­sis, it is now idle. “Many of the dry re­gions of the world are in the process of build­ing or have de­sali­na­tion plants,” said Claire Pen­gelly, wa­ter pro­gramme man­ager at Green Cape. “But the big fear is – what hap­pened in Aus­tralia – there is a mas­sive drought, ev­ery­one starts pan­ick­ing, de­sali­na­tion is built and then the rains come.”

In an emer­gency, things can move a lit­tle faster, Bray­brooke said — al­though, with de­sali­na­tion plants, en­vi­ron­men­tal im­pact as­sess­ments still need to be done and ma­rine con­sul­tants must be brought in.

Sea wa­ter dif­fers in com­po­si­tion, so each de­sali­na­tion plant must be adapted to en­sure the pre­treat­ment is cor­rect, Bray­brooke said. The West Coast, in par­tic­u­lar, is high in or­ganic con­tent and in­cludes phe­nom­ena such as red tides, and a de­sali­na­tion plant must be able to deal with that. To put a stan­dard­ised plant up and ex­pect it to work could be a to­tal dis­as­ter, he said.

He added that Cape Town is well aware of the com­plex­ity of es­tab­lish­ing a de­sali­na­tion plant. Still, Cape Town is con­fi­dent it can pull off the wa­ter aug­men­ta­tion pro­gramme, which it de­scribes as be­ing “un­prece­dented in scale”.

“We are do­ing in months what it would usu­ally take years to do,” the city said in a state­ment. “We are able to progress be­cause of our proac­tive long-term plan­ning and good gov­er­nance mech­a­nisms.”

If the city taps did run dry, in­dus­try will have to shut down and poor san­i­ta­tion could see the rapid spread of in­fec­tious dis­eases.

“I think de­sali­na­tion is an ab­so­lutely valid ap­proach to fol­low now, given the cri­sis. In Cape Town, there are no more sites to dam. Berg River Dam was touted to be the last dam — from there on, Cape Town should save wa­ter,” said Kobus van Zyl, a Univer­sity of Cape Town pro­fes­sor and hy­draulic en­gi­neer.

“The prob­lem with de­sali­na­tion is just the cost,” he said.

Apart from the cost of build­ing a de­sali­na­tion plant, the cost to pro­duce potable wa­ter can be six times higher be­cause forc­ing sea­wa­ter through a mem­brane is an en­er­gy­in­ten­sive process.

Ac­cord­ing to the Wa­ter Re­search Com­mis­sion, un­der nor­mal cir­cum­stances Cape Town can pro­duce wa­ter for R1.25 per 1 000 litres us­ing a mix of wa­ter sources. But the cost of pro­duc­ing wa­ter from a large de­sali­na­tion plant at the coast is be­tween R5.80 and R8.30 per 1 000 litres.

“What peo­ple for­get is that, in a drought, the cost of treat­ment will go up re­gard­less,” said Bray­brooke, adding that when there is a short­age you can’t be choosy about the qual­ity of wa­ter.

There are also costs re­lated to shut­ting off a de­sali­na­tion plant, he said. “This tech­nol­ogy does not like to be turned on and off.”

For one, he ex­plained, you are work­ing with mem­branes, each of which is ex­pen­sive. When moth­balled, they need to be pre­served with special chem­i­cals to en­sure they don’t lose their func­tion­al­ity.

What­ever the mea­sures, ful­fill­ing the city’s wa­ter needs is not go­ing to be cheap. It was orig­i­nally es­ti­mated that Cape Town would have to di­vert R3.3-bil­lion from its bud­get to in­sti­tute the first phase of emer­gency mea­sures. Ap­proval for a di­ver­sion of funds was granted by the national trea­sury this week. How­ever, the city can­not yet say how much the emer­gency pro­gramme could cost, other than to say it is a “multi­bil­lion-rand” ini­tia­tive.

“The to­tal cost of the pro­gramme will be avail­able when the var­i­ous pro­cure­ment pro­cesses have been com­pleted. It is currently a fluid process based on ten­der in­puts,” said Jo­han van der Merwe, the city’s may­oral com­mit­tee mem­ber for fi­nance. He said the city is con­fi­dent it can fi­nance the emer­gency pro­gramme by repri­ori­tis­ing funds and us­ing sav­ings and cash re­serves.

“Bring­ing so many new tech­nolo­gies on­line si­mul­ta­ne­ously at mul­ti­ple sites around the city is ex­pen­sive and, as such, un­der the Mu­nic­i­pal Fi­nance Man­age­ment Act, our fi­nance team is work­ing on mak­ing fund­ing sources avail­able, in­clud­ing cash, repri­ori­ti­sa­tion of ex­ist­ing wa­ter projects, a con­ces­sion­ary loan from an ex­ter­nal fun­der, and cur­tail­ing ex­pen­di­ture else­where in the ad­min­is­tra­tion,” he said.

Tar­iffs, in­clud­ing wa­ter and rates, have been es­tab­lished for 20172018 and can­not be ad­justed, which means con­sumers will not face higher costs for the re­main­der of this fi­nan­cial year.

“While the city will do ev­ery­thing in its power to curb ex­pen­di­ture across the ad­min­is­tra­tion to re­duce the im­pact on fu­ture tar­iffs, we can ex­pect tar­iff in­creases sig­nif­i­cantly above in­fla­tion in the 2018-2019 fi­nan­cial year,” Van der Merwe said.

But the city is con­cerned that a user-funded ap­proach will not be sus­tain­able with­out large pop­u­la­tion growth, which would pro­duce more favourable economies of scale, so it is ex­plor­ing other fund­ing mod­els that won’t over­bur­den res­i­dents fi­nan­cially, Van der Merwe said.

The trea­sury’s green light will also al­low the city to by­pass some red tape and speed up pro­cure­ment pro­cesses.

Graphic: JOHN McCANN Data source: STACKEXCHANGE, TREEHUGGER

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