Blocks of soon-to-be-completed residential apartments tower over the simple fish farms that are a feature of Shanwei, a rapidly expanding city in South China's Guangdong province. [China Daily]

On the coast of Guangdong province, two hours northeast of Shenzhen, is a city with a population of about 3.5 million, 500,000 more people than Chicago, and an annual GDP growth rate of about 17 percent. Few people have heard of this city.

With wide, tree-lined streets, ramshackle factories and bustling alleys lined with stalls offering everything from fresh fruit to motorcycle repairs, Shanwei would be a major urban center in almost any other country.

Instead, in China, it is merely one of scores of cities overshadowed by sprawling metropolises like Beijing, Shanghai, Shenzhen and Guangzhou.

However, fast-growing but largely anonymous cities like Shanwei are increasingly driving the country's development.

Management consulting firm McKinsey estimates that, by 2025, China will likely have 221 cities of at least 1 million people and that the country's urban population will have grown by 350 million. The firm also predicts that about 90 percent of China's GDP will eventually come from the country's urban economy.

"The success of China's economic growth model hinges on successfully managing a truly colossal scale of nationwide urbanization," said John Delury, associate director of the Center for US-China Relations at the New York-based Asia Society.

"The stakes could not be higher," Delury said.

At the center of Shanwei is Zheng Yanxiong, the city's mayor. An overworked, balding 47-year-old man, Zheng is responsible for turning this once sleepy backwater into a major city - and turning it into that fast.

The issues and pressures he faces offer a fascinating window into the challenges of governing a country that in 15 years could have 1 billion urban residents.

Zheng is perhaps an unusual mayor. Soft-spoken, earnest and a self-professed bookworm, he is a former People's Daily reporter with a doctorate in legal studies from Wuhan University. He grew up in Shantou, a slightly larger city a couple of hours up the coast.

Although considered relatively young for the post, Zheng was appointed mayor in 2008 after leading Shanwei's discipline and inspection department and the city's politics and law committee, a Party organization that supervises the city's courts and public security bureau.

Perhaps as a result of his academic and media background, he has also developed a reputation for accessibility and candor, giving frequent interviews to the media and responding directly to questions on online bulletin boards and in e-mails to citizens.

"He's more open than cadres who have come up from the countryside, and more willing to try new things," said Lin Jianxiong, director of operations at Truly Semiconductors, Shanwei's largest employer and a major supplier of LCD screens to international companies, including Samsung, LG and Lenovo.

The challenges Zheng faces are hardly unique, however. Like many Chinese cities, Shanwei consists of a rapidly expanding industrial center surrounded by farmland, rice paddies and smaller factory towns. Zheng believes that to continue growing, Shanwei needs two things: outside investment and the basic infrastructure and social services necessary to support that investment.

Managing those priorities is an exhausting job. A typical day for Zheng begins at 8 am and usually involves multiple banquets with prospective investors and visiting government officials. He visits local businesses and factories, has meetings and briefings with his deputies, city planning experts and other Shanwei officials. When he returns to the office after dinner, he reads reports and project proposals and answers e-mails. He often does not finish until well after midnight.

"To improve the daily lives of Shanwei's citizens, there is still so much to do," said the mayor, ticking off some of his latest concerns: Managing the opening of a new hospital, expanding the city's education system, the construction of two new wastewater treatment plants, whether and how to expand a wind power plant, planning for the city's growing traffic and, of course, the economy.

"If we talk about a city in the fast-urbanizing, fast-development stage, you would start with the basic mandate for economic development, and that's the hunt for investment," said Jonathan Woetzel, a director in McKinsey's Shanghai office and lead author of a major study into urbanization in China.

Despite its recent growth, the pressure is especially acute in Shanwei, partly because it has one of the least developed economies of any urban area in Guangdong.

Per capita GDP in the city is just 10,521 yuan (US$1,500), compared to the national average of about 26,520 yuan and Shenzhen's 89,814 yuan.

"As mayor, my biggest challenge is to keep the economy growing as fast as I can," said Zheng. "I spend two thirds of my time meeting with potential investors. I'm a little like Shanwei's advertising director."

In some ways, he continued, launching into a well-practiced pitch, Shanwei today resembles Shenzhen two decades ago. With both labor and real estate prices skyrocketing in China's major cities, Shanwei has all the qualities that made Shenzhen initially attractive to investors: cheap labor, land, energy and water, and proximity to a major developed metropolis.

"If companies want to keep expanding, they have to go to China's interior," he declared. "And the first stop must be cities like Shanwei."