Over the past two decades, this old trading town in southern India has been transformed into a bustling business city as software companies, call centers and factories set up here. Dozens of colleges, air-conditioned shopping malls and international gyms now dot its leafy lanes.

But like many emerging Indian cities, Hubli is ill-equipped to cope with the growth. Piles of garbage lie uncollected on street corners, and vehicles clog the narrow roads. Most residents have access to clean water for just a few hours a week.

More than 600 million Indians will live in cities by 2030, up from 350 million today. About 70 percent of new jobs will be created in cities by 2030, fueling the national economy like never before.

But the government says the country’s infrastructure is unprepared for the massive urban growth. Only 20 percent of India’s urban sewage is treated before disposal, and few cities have sanitary landfills for solid waste. Out of 85 cities with over half a million people, only 20 have local bus service. India needs to invest more than $860 billion in urban infrastructure over the next 20 years, officials say.

“Our cities are bursting at their seams with people, but urban services are lacking. We don’t have enough trained town planners. Our cities are growing without any plan,” said Kamal Nath, the urban development minister in New Delhi.

With more than 900,000 people, Hubli is emerging as an example of the problems and the promise accompanying India’s urban boom as cities of its size look for ways to prepare for new growth.

Two decades ago, Hubli was a cotton and chili trading town, connected to the rest of India only by train. But it began to grow as businesses looked for places to expand beyond expensive and clogged large cities and as the number of college-educated young people began swelling in small towns. Two large, national highways were also constructed through Hubli.

Its small airport, which began functioning in 2006 with propeller planes, is now expanding its runway to make room for wide-bodied Boeing 737s to land. Officials are trying to combat the rising number of private cars and encourage public transport by building dedicated lanes for buses.

But one of Hubli’s most dramatic projects focuses on overhauling the city’s water supply model to keep up with growing aspirations of its residents. With a $39 million grant from the World Bank, the water department began a pioneering experiment in 2008 to deliver water to five neighborhoods 24 hours a day. The project’s success has triggered a clamor for similar programs not only in other neighborhoods, but also other Indian cities.

Until recently, Hubli residents used to skip work and school to line up for water, which was delivered by the city every eight days.

“Sometimes they supplied water in the middle of the night and everybody would run to the taps. Fights would break out. It was like living in a village, not in a city,” said Saleema Sattar, 41, an accountant who lives in a low-income neighborhood.

At first, round-the-clock water was unimaginable for the residents here. They thought the city would quickly run out and feared that their bills would be too high. The city council’s waterworks staff thought that the French company called in to manage the water supply would fire them.

But now, residents pay for their water, and officials say that there is less waste and fewer cases of waterborne diseases.

“This has been a miracle. We can turn the tap on anytime of the day and there is water,” said Girija Manjunath, 31, who lives in a blue-collar area that now receives water. “It has freed me from water worries. My children are cleaner and go to school. Others in the city envy my destiny now.”

The transformation was not easy. Fifty-year-old pipelines, which were cracked and leaking badly, had to be replaced with a new underground water distribution pipes.

“The cracks used to suck external filth and sewage into the water pipes. The old water pipes had been laid very close to underground drainage. This was the cause for constant waterborne diseases in the city,” said M.K. Managond, a senior engineer in Hubli’s water department.

What was worse, Hubli did not have a database on the state of its water pipelines. Officials did not know where they were, where they were leaking or the extent of illegal tapping. When a pipe broke, it took weeks for the city council to find and fix it.

The success of the 24-hour water supply program in Hubli has fueled other aspirations as well — for better public parks, wider roads, traffic management and street lights.

“Our ambitions are growing. It is like a frog coming out of a pond and discovering that the river is bigger,” said Madan Desai, former president of the chamber of commerce in Hubli. “Small towns don’t want to be in stagnant waters anymore.”