The city of Osaka on Monday began dredging the Dotonbori River, a favorite target for revelers to celebrate sports wins by jumping into the waterway.

The local Hanshin Tigers currently hold a comfortable lead in the Central League, and fan enthusiasm is at fever pitch.

But city officials said they are not dredging the Dotonbori out of consideration for jumpers, adding it is dangerous to leap into the river. Osaka Gov. Fusae Ohta told a news conference last month, "This is a good opportunity to dredge the river bottom.

"By the time (the team) clinches the victory, we want everyone throughout the nation to see the district's healthy atmosphere and clean water."

The area along the Dotonbori in downtown Osaka is a well-known amusement center. It is also a place where people often dump bicycles in the river. The city collected some 160 bikes when it last cleaned the waterway in May 2000.

Many sports fans jumped into the Dotonbori from the Ebisu Bridge and nearby spots in 1985 when Hanshin last won the Japan Series. Last summer saw plenty of leaping as the Japanese national soccer team did well in the World Cup soccer finals.