The Rideau Valley Conservation Authority returned to Mud Creek for a two-year check up on a campaign it launched to free the riverbed of the invasive species, Himalayan Balsam, finding the area largely free of the plant.

Justin Robert, an aquatic resource technician with the watershed oversight body, suggested the hot, dry weather of this summer may be helping to slow the spread of certain invasive species.

In July 2014, the RVCA and some of its volunteers carried out an eradication campaign against an invasion of Himalayan Balsam, or Impatiens glandulifera, near Lockmaster Crescent, northwest of Manotick's downtown.

The tall plant with a bright pink flower was introduced to North America as a garden ornamental.

It grows quickly wherever water is present and can very rapidly crowd out native vegetation and leave riverbanks vulnerable to erosion.

The Rideau Valley Conservation Authority's Justin Robert says efforts to rid Mud Creek of Himalayan Balsam have been successful. (Stu Mills/CBC)

'We removed it'

Robert returned to Mud Creek for a follow-up visit to see if he and his crew had managed to banish the balsam for good when it hand-plucked about 10 garbage bags full of the plant from the river banks.

"I think things look quite positive — because if the plant had taken off we'd see it on the shorelines here," said Robert, surveying an area of land leading to the creek.

"We came in here, we targeted the plant, we removed it — now we're just seeing if there's any re-growth and if we need to maintain any sort of activity in the area," he explained.

The Himalayan Balsam's pink flowers blossom on the riverbank, then drop into the creek where currents carry them and their seeds downstream where new populations are established.

It doesn't take long for flotillas of invading Himalayan Balsam to clog an entire creek.

"They'll out-compete the native vegetation," said Robert of the ornate plant introduced to North America from its native Nepal in the early 1800s.

"It's covering parts of the slope that need to be stabilized and its root system isn't dense like a lot of the native plants, so we're seeing enhanced erosion in the area, whereas native plants might be able to actually bind the soils and hold it together."

The riverbed area behind a Manotick subdivision was clogged with Himalyan Balsam in 2014. (Stu Mills/CBC)

Only straggler plants found

This survey of Mud Creek turned up only a handful of straggler plants. Robert said given the Balsam's reliance on water, the hot, dry summer and low water levels have likely been allies in the prevention of the spread of this invasive plant

The RVCA check-up was welcomed by Ed Kwok, who moved to the then-new neighbourhood with his family in 2014.

"That's actually one of the plusses when we came, looking for different houses," said Kwok, who said his family had chosen the suburban setting after living in Ottawa's downtown.

"To know that this area is protected, looked after by the (Rideau Valley Conservation) Authority, so that's actually a bonus for us."