Shanghai plans to use satellites to protect its small waterways from being reclaimed by property developers, officials with the Shanghai Water Authority revealed Sunday.

The authority is in talks with an unnamed military department to buy pictures taken by its satellites as they pass over the city. The contract will be sealed by the end of this year, authority officials said.

"The pictures will help us get more exact and timely information on the condition of numerous local waterways, with which we can locate places where the waterways have been turned to land," said Wei Zixing, a top official with the authority.

The city has 23,787 waterways of different sizes, which run a combined 21,646 kilometers in length and cover 533 square kilometers of surface areas.

Reclaiming waterways into land used to be a serious problem in the city, especially in suburban areas. From 1989 to 1999, the size of local waterways decreased by 180 square kilometers in terms of the surface area.

The problem is mainly created by real estate developers and industrial parks, which reclaim land without proper permission, according to the authority.

The decreased waterways put the city at risk in the rainy seasons when the waterways water holding capacity will fall short of the rainfall, causing rivers, creeks and lakes to overflow.

The reclaimed waterways, in certain areas, will also block water transportation.

Though Wei stressed the situation is under better control at present, he couldn't provide any numbers to prove waterways are being protected.

"Previously, we had to depend on a massive survey on local waterways. It can't be done every year for the work requires too much manual labor and money. This made it difficult to conduct close supervision," said Wei.

The authority plans to buy the pictures once a year. It will then ask a map making company to analyze the pictures, which can spot any river wider than 1.4 meters.

(Shanghai Daily April 26, 2004)