The rapid growth of Asian cities often condemns millions to a wretched life in slums. But in Bangladesh's capital Dhaka, the fastest growing megacity in the world, even middle-class life can be miserable. Housewife Sultana Begum has learned to cope without reliable gas or electricity and to navigate flooded roads, but it's the endless piles of festering garbage in her Dhaka neighbourhood that drive her mad. "There is rubbish everywhere, the city doesn't do waste collections here," she told AFP at her first-floor apartment in Keraniganj, a bustling, middle-class area in the south of the city. "People dump garbage at the sides of the road and it rots in the sun for days -- it smells so foul," she said. Dhaka's population has exploded from just some 300,000 at independence in 1971 to 13 million and counting. It is ranked by the World Bank as the world's fastest-growing megacity -- defined as an urban area of more than 10 million people. The city's growth -- it is expected to be home to more than 20 million by 2025, according to the UN -- has been almost entirely unregulated. Most of the some half-million migrants who arrive each year in search of jobs and a better life end up in vast, sprawling slums. But the unplanned growth has also made things difficult for millions of middle-class citizens like Sultana in new areas like Keraniganj. "It's just miserable -- no gas, no power, flooded roads, rotting garbage everywhere. Really, living here is a pain," Sultana said. Her problems are typical of all new areas across Dhaka which were developed "spontaneously" with no planning or oversight, said planning expert A.K.M. Abul Kalam. City and local authorities are badly organised, under-funded and lack manpower so have never enforced Dhaka's 1995 development plan, said Kalam, who heads Jahangirnagar University's urban and regional planning department. "This is fundamentally the major problem of the city -- the master plan has not been implemented. And now we have so many problems, managing the city has become very, very difficult," he added. Building codes and zoning laws are routinely flouted and whole residential neighbourhoods have been built without proper drainage, water or sewage systems, he said. Chronic power and gas shortages led the government to impose a ban on new connections in 2009, meaning many new Dhaka residents simply cannot get connected to state-run utilities. Even for those who are on the grid, the city's rapid expansion and booming economic growth have created a constant utilities crisis. Dhaka has a daily shortfall of 2,000 megawatts of power, which is half of the entire country's average daily production. "We have four or five power cuts a day. If it is hot, the power cuts are more frequent. It's terrible," said Mahamudal Hasan, 25, who has lived in Keraniganj for four years and owns a mobile phone shop. The capital needs 2.2 billion litres of water a day but the city's water authorities can supply just 1.9 billion litres, according to official figures. Many public pumps operate below capacity because of a gas shortage. "The water from my taps is green and smelly. I have to spend two hours a day waiting at the tube well to get clean water," Rukia Begum, an employee at state oil company PetroBangla, told AFP at a water pump in central Basabo area. "It is a huge hassle. Do you know how much easier my life would be if the taps actually produced water I could use rather than some filthy liquid?" she asked. In a bid to find a quick fix to the energy crisis, the government says it has fast-tracked the approval process for foreign firms to set up new power plants and that the approach has already achieved results. "There is an improvement... we have added in the last 2.5 years about 1,800 megawatts, including those plants which are running under test run," said Power Development Board chairman Alamgir Kabir. "We hope that by early 2013 we will be able to come out of this power cut situation." But back in Keraniganj, Kabir's assurances are of little comfort for Muhammad Mahub Alam, 46, as he uses a torch to survey the flooded lower half of his house. "Power cuts are acute and the ground floor of my building floods every time it rains as the local authorities built the main road too high and didn't put in proper drainage," he told AFP. "There's no water in the taps but we have to wade through ankle-deep water to go out. I've lived in this area for 10 years but we're all pretty sick of it now."