Pothole plagued Harare seeks to build climate-resilient roads

Thomson Reuters Foundation, trust.org

Can concrete roads help keep Zimbabwe's capital moving as flooding worsens?

By Jeffrey Moyo

Harare - Heavy traffic snakes through downtown Harare, Zimbabwe's capital, manoeuvring along the potholed roads as impatient motorists hoot at one other, while pedestrians try to cross the congested streets, weaving through slow-moving cars.

The city's asphalt road network is in dire straits, and will only get worse as damage from flooding and freak weather increases due to the impact of climate change.

The solution - say engineers, city planners and campaigners - is concrete roads.

The city council has already decided to replace high-maintenance asphalt with concrete, but there is no clear timeframe or budget.

"It's a project that we want to see take off as soon as possible," said Michael Chideme, spokesman for Harare City Council. "We view these (concrete) roads as strong roads - roads that are resilient in terms of the vagaries of weather, so once we have these roads, they will not be susceptible to being washed away by storms."

Some other African countries have already embraced concrete roads, shifting away from asphalt - including Malawi, Ethiopia and South Africa.

Chideme said all roads around Harare would be rebuilt using concrete, starting with the Arcturus Road, a main artery that connects the capital to Mashonaland East Province.

Low maintenance

"Research studies that have been done already by our team of quantity surveyors and civil engineers show that well-designed cement roads require little or no maintenance that lasts a 40-year lifespan," Chideme told the Thomson Reuters Foundation.

Many Harare drivers, like Luckmore Mhike, welcomed the prospect of concrete roads.

"I have endured driving my only car amid potholes for over a decade, and surely if the state of our roads could be improved by building concrete roads, I tell you I will be the happiest motorist," Mhike said.

Climate change experts think concrete will be more robust in the face of worsening floods and heat, as global warming brings more extreme weather such as Cyclone Dineo which pummelled Zimbabwe earlier this year.

The storm washed away some roads, tore gullies into others and washed away tar surfacing.

"Take into consideration the way our roads countrywide were wiped out by Cyclone Dineo, and imagine if the roads were concreted. Surely, they would have withstood the caprices of the cyclone," said Happison Chikova, an independent environment and climate change expert.

Civil engineering consultant Gilbert Motsi said concrete roads better withstand changes in temperature and humidity.

"The surface of a concrete road is solid, and it keeps its properties over time, free from climate change effects," he told the Thomson Reuters Foundation.

"Without being concreted, our roads will continue to suffer various stresses as a result of climate change impacts - flooding, erosion of their edges and foundations, and loss of road structure uprightness."

Invest once

Zimbabwe last year launched a national road survey to determine the cost of replacing asphalt roads with concrete.

Harare city council's director of works, engineer Phillip Pfukwa, said putting in a concrete road would be four to five times more expensive than an asphalt tar road.

As a result, the capital's rate-payers worry they will end up forking out more money on tax bills.

"Whether or not concrete roads will be the answer to climate-induced destruction, I am afraid the burden of paying more will fall on us," said Douglas Mbalekwa, a resident in Harare's Mabelreign middle-income suburb.

Mbalekwa is also a member of the Combined Harare Residents Association, a civil society group that advocates for effective and affordable municipal services.

But local authorities are convinced concrete roads will be worth the up-front investment.

"Research has shown that well designed cement roads require little or no maintenance well beyond their 40-year design lives, while concrete roads are also not damaged from oil leaks like asphalt roads," said Pfukwa of the city council.

The roads are especially suited to countries that experience heavy and often torrential downpours, he said.

A half kilometre concrete stretch of road the Mvuma road in Zimbabwe's Midlands Province, constructed as a pilot scheme more than 20 years ago, is still intact and undamaged, he said.

The investment in concrete roads would soon lead to cost savings, said Harare council spokesman Chideme. "We have seen that year in and year out, we are investing a lot of money in the same roads, doing road patching," he said. "It is better to invest once, and then do periodic road repairs than to say every few months you go back to the same road after it has been affected by the weather." 

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