BAMAKO (AFP) - Anarchic architecture, unchecked pollution and high costs of living are the lot of African city dwellers, experts warn, as living standards fail to keep pace with rapid urban growth on the continent.

The Bamako Forum, a pan-African think tank, recently considered the phenomenon of African urbanisation against the backdrop of a city living the results of rural flight clashing with poor urban planning.

At 1.8 million inhabitants Bamako is far from Africa's largest city. But its 5.5 percent growth rate is the fastest on the continent, outstripping that of established African megalopolises like Cairo, Kinshasa or Lagos.

One billion Africans will live in a city by 2040, according to World Bank estimates, compared with almost half a billion today.

"Such growth has never been seen globally, and probably never will be again," said Somik Vinay Lall, the bank's top urbanisation expert, speaking at the forum.

Visitors to Bamako's dusty streets don't have long before they chance upon what residents have nicknamed Lafiabougou Hill, a pile of stinking rubbish that at one point loomed 20 metres tall in the city centre.

Lacking fuel to transport the trash to depots on the city's edges, Lafiabougou Hill has become a pungent reminder of the municipality's inability to provide basic services to its rapidly expanding population.

"We have protested, burnt tyres, blocked off roads, because this affects the health of the people living in this area," said Djiri Nimaga, head of a local youth group that held protests last year aimed at rousing action from the authorities in the ACI 2000 commercial district.

Until now Lafiabougou has not killed anyone directly, but at least 113 people were killed in a giant landslide at Ethiopia's largest rubbish dump last weekend, including several children.

- Vicious circle -

The Western perception of poor countries having low costs of living, true across much of Asia, does not hold true for Africa, where some of the world's most expensive cities are populated by some of the planet's poorest people.

As a result, manufacturing and services, driven by consumer spending, are all too often absent.

"Twenty-three per cent of land in Ho Chi Minh City is taken up by industrial and commercial activity, compared with 5.9 per cent in Nairobi and 1.1 per cent in Addis Ababa," Lall emphasised.

A World Bank report entitled "Africa's Cities: Opening Doors to the World", released in February, said deep-rooted problems with the way land was bought and sold, a lack of investment in infrastructure and an absence of regulation constrained African cities.

"Closed to regional and global markets, trapped into producing only locally traded goods and services, and limited in their economic growth," is how the report characterised cities such as Bamako.

- Thriving on disorder -

Ousmane Sow, who works for Bamako's city council, is building up an "urbanisation agency" of the kind encouraged by international development bodies, but says little will fundamentally change until basic rules are respected.

"Say a neighbour has the permit for a one-storey structure, he will build a four-storey one. Buildings fall down all the time," Sow said.

"You can't do architecture on the fly, you are putting people's lives at risk. Behind all of this is the issue of impunity, the true evil of this country," he added.

Among the chaos, some are making fortunes.

In Abidjan, Ivory Coast's largest city, a single square metre of land can fetch one million FCFA (US$1,625), encouraging ever more landlords to bend the rules.

The small minority of those private or public investors controlling the market "love urban disorder because it's all about gambling on property," said Jean-Pierre Elong Mbassi, secretary-general of the CGLU African local government association.

"They aren't interested in whether the city actually works as long as they can get such a high rate of return, which happens specifically because the city doesn't function," he added.

Back at Lafiabougou Hill, trucks are waiting to load rubbish dragged to the site by donkey carts.

"As soon as they stop taking it away, the trash just piles up again. It takes too long," Nimaga said.