A government plan to build the world's tallest river navigation tower on China's longest river, the Yangtze, in the western city Chongqing has sparked an online storm over whether it will be anything more than a showcase project.

After the plan was reported last Thursday, netizens swarmed the city's website, cq.qq.com, questioning the purpose and cost of the plan, which is still under feasibility study.

One netizen claimed the cost of the project, which the government has put at about 10 million yuan (1.46 million U.S. dollars), would be enough for building 50 schools for impoverished rural kids.

Under the plan, the tower would be taller than the current world record holder, which is the 68.8-meter Jieyang Tower in south China's Guangdong Province. The city contends the tower is necessary for navigation safety.

However, the planner has not designated a specific height for the tower.

In answer to public concerns, Bi Fangquan, director of the Chongqing bureau of Yangtze River Administration of Navigational Affairs, said Tuesday that the tower had to be very tall, as Chongqing was upriver of the Three Gorges Reservoir.

The reservoir had been filled to 175 meters since September, inducing a seasonal rise of water level near Chongqing to 30 meters at maximum, Bi said, adding the tallest tower currently in the reservoir area was only 15 meters above the water.

"Many cruise boats and cargo boats sail in the area everyday, and the tower signals cannot guide them safely across the area," Bi said.

He added that the new tower will not only guide the navigation, but also send out radio waves through which maritime and navigation bureaus can contact with these boats.

The bureau said last week that the tower has been planned at the Jiangbeizui area, where Yangtze River and Jialingjiang River meet.

"It will not only play great navigational functions but also become a tourist resource," said Bi.

The project location faces Chaotianmen, where the Jialing River, Yangtze's major subsidiary, enters the city.

The bureau hoped the tower would be a new city landmark.