Rowing's weed menace uprooted

Underwater mowing has rooted out weeds that threatened to clog rowing and canoeing events at the Sydney Olympics' regatta course.

Olympic officials told Reuters two months of clean-up work had cleared the course of thick clumps of underwater weeds which had caused problems at the Australian kayaking championships.

Competitors complained oars kept getting tangled in the weeds which were planted in the man-made river and lake system to protect its ecosytem but spread out of control.

"I think the work that has been done in deep-harvesting, selected removal and matting will ensure a fair field of play for rowers and canoeists alike," a Sydney Olympic spokesman said.

Rowing venue manager Les Murphy said the course water level had been lowered 1.5 metres and the course "deep-mown" during the clean-up.

"A mower dropped down three metres and that was followed by the laying of deep plastic mats across the worst weed areas. The water level is now back up to normal and they're just clearing up the weeds around the edges," Murphy said.

"It's all looking lovely and clear at the moment." The clean-up operation cost an estimated $600,000 (US$354,000).

"We've been told the problem is well in hand," Rowing Australia chief executive Darren Peters said.

Australian Canoeing general manager Jon Bisset is confident the issue has been dealt with ahead of next month's Olympics.

"We're very confident things will be fine for the Games. But we're very concerned about a long-term solution," Bisset said.