'Nothing could survive in there': Silt build up choking Grand River near Parkhill Dam, causing concern

Drastic sediment buildup in the Grand River near Parkhill Dam is leaving some residents of Cambridge feeling concerned.

Many people have been noticing the severe silt building up for the last 20 years. It's now so bad that some residents are worried about the impact it's having on wildlife living in the area.

Silt is sediment typically made up of rock and mineral particles that accumulate on river banks by travelling through water, ice and wind over a span of several years.

But Bryan Duross, a concerned citizen, says the silt buildup happening in that area of the Grand River is anything but normal.

"The fishery in that stretch of the river has been totally decimated. There is nothing alive in there," Duross told CBC News.  

"Normally when you're taking depth sounder readings, if there are any fish, that would be picked up on the sonar. We didn't see any evidence of that. Given the depth of the silt, the coverage of the silt, nothing could survive in there. That river from the Park Hill Dam up to the golf course is essentially dead," he said.

Ron Dowhaniuk, president of the Cambridge Rowing Club, says the river is slowly turning into marshland.

"There are now islands forming along the west bank of the Grand River right at that spot. That vegetation is now starting to grow on it, so it's narrowing the river," he said, adding the buildup is particularly bad along the west side of the river, near River Bluffs Park.

"That has resulted in us having to push our docks out further by about 25 feet over the last 20 years so that we can launch our rowing sculls."

Speculation over cause of buildup

Duross says he first began to notice silt buildup when the sluice gates at Parkhill Dam were permanently closed about 20 years ago.

The gates were closed to prevent more drowning deaths after a police officer died trying to save a 12-year-old boy in 1998.

Duross says that decision to close the gates has rapidly worsened the state of the silt in the river.

"The blocking of the sluices was a quick and dirty way to make sure that the drownings wouldn't happen again. But unfortunately, they gave no thought whatsoever to the consequences," he said, adding that when he asked the Grand River Conservation Authority (GRCA) to send him documentation with more details about the decision to close the sluice gates — he was surprised to find there was not much.

"No one thought to ask, 'Well, wait a minute, why are those sluices built into them? Why are they there? What do they do?'... In reviewing those [documents provided by the GRCA], not once did the words fishery, silt or navigable waterway come up," Duross said.

Dowhaniuk wonders what else is mixed up in the sediment build up.

"In the build up of silt, there could be harmful chemicals, heavy metals and dioxins," he said. "What is in the silt and is it a health issue or could it be a health issue?"

To urge the local municipality and regulatory authority to do something, Duross says he has drafted a report for the GRCA, detailing the history of the Parkhill Dam, what he thinks may have led to the buildup, and solutions on how to clean up the river.

In a statement to CBC News, Pam Wolf, a regional councillor who represents Cambridge and who is a member of the GRCA board, says she will be discussing Duross' report with board members this week.

She says they also plan to meet with both Duross, Dowhaniuk and other staff to help determine what the next steps will be.