Mar. 19, 12:51 EDT
Windermere Basin wetland may solve dredging problem
'Wild idea' merits economic, environmental consideration
Eric McGuinness
The Hamilton Spectator
Windermere Basin is little more than a barren mud flat at the east end of Hamilton Harbour, its shallow water covered with algae in the summer.
But one key official thinks it could become a green gateway to the city, a fish nursery, bird sanctuary and a filter for treated sewage flowing into the bay.
The 17.5-hectare basin was designed to trap sediments washing down Red Hill Creek and fine solids discharged from the Woodward Avenue sewage treatment plant, so they wouldn't clog channels used by big cargo ships.
It's done the job so well it's almost filled and sediment is overflowing. Dredging the basin could cost city taxpayers $18 to $22 million.
Jim Harnum thinks it might make sense to turn it into a cattail marsh fertilized by organic material carried by the creek. As senior director of water and wastewater for the city, Harnum's interest is as much economic as environmental, because a contract with the port authority commits Hamilton to dredging the basin regularly so sediment doesn't interfere with shipping.
A survey last December found that about 250,000 cubic metres of mud had filled the trap since 1990 and that some was escaping into the open harbour. To understand the problem, picture a mud pie seven and a half storeys tall covering an entire Canadian football field. That's how much material has collected.
Removing it could mean dredging, drying and trucking hundreds of thousands of tonnes to a landfill site where disposal would cost $42 a tonne.
The old Board of Hamilton Harbour Commissioners was responsible for dredging the basin until the city took responsibility for Windermere and acquired the surrounding land when the port authority was established five years ago.
It was part of a deal in which the city also gained title to much of the west harbour shore for recreational use.
The city has hired a marine engineering firm to report on dredging options, but Harnum doesn't want to leave it at that. He wants to look at alternatives to repeated dredging, including creating an artificial wetland, while also reducing soil erosion along Red Hill Creek and the flow of fine suspended particles in treated sewage discharged just upstream of the basin.
"The very next day after we dredge, it will start filling up again, so we want to look at a long-term solution," he said in an interview this week. "What that is we don't know yet. We might issue a request for proposals to see what the engineering world can come up with.
"Work in the valley (related to expressway construction) will dramatically reduce bank erosion, and our long-term goal is to meet the harbour Remedial Action Plan targets for total suspended solids in sewage effluent, but those are five- to seven-year plans.
"So we've got this wild idea to turn it into wetland. If we filled it more and put plants in, the organic material would get absorbed and we wouldn't have algae. Maybe that would cost $5 million and act as tertiary treatment for the wastewater plant.
"It may be pie in the sky. I don't want to just throw $25 million away, and we have a contractual obligation with the port authority. We said we would not let it impact shipping lanes."
Marilyn Baxter, executive director of the Bay Area Restoration Council, thinks the idea merits further study by all the Remedial Action Plan partners. She notes the city received a SuperBuild infrastructure grant to improve public access to the basin, but that project is on hold because it might be necessary to put dredged sediment on the shore.
emcguinness@thespec.com
905-526-4650
Hamilton Spectator File Photo
The Windermere Basin is filled and sediment is overflowing. Dredging the basin could cost taxpayers $18 million to $22 million.
Windermere Basin wetland may solve dredging problem
'Wild idea' merits economic, environmental consideration
Eric McGuinness
The Hamilton Spectator
Windermere Basin is little more than a barren mud flat at the east end of Hamilton Harbour, its shallow water covered with algae in the summer.
But one key official thinks it could become a green gateway to the city, a fish nursery, bird sanctuary and a filter for treated sewage flowing into the bay.
The 17.5-hectare basin was designed to trap sediments washing down Red Hill Creek and fine solids discharged from the Woodward Avenue sewage treatment plant, so they wouldn't clog channels used by big cargo ships.
It's done the job so well it's almost filled and sediment is overflowing. Dredging the basin could cost city taxpayers $18 to $22 million.
Jim Harnum thinks it might make sense to turn it into a cattail marsh fertilized by organic material carried by the creek. As senior director of water and wastewater for the city, Harnum's interest is as much economic as environmental, because a contract with the port authority commits Hamilton to dredging the basin regularly so sediment doesn't interfere with shipping.
A survey last December found that about 250,000 cubic metres of mud had filled the trap since 1990 and that some was escaping into the open harbour. To understand the problem, picture a mud pie seven and a half storeys tall covering an entire Canadian football field. That's how much material has collected.
Removing it could mean dredging, drying and trucking hundreds of thousands of tonnes to a landfill site where disposal would cost $42 a tonne.
The old Board of Hamilton Harbour Commissioners was responsible for dredging the basin until the city took responsibility for Windermere and acquired the surrounding land when the port authority was established five years ago.
It was part of a deal in which the city also gained title to much of the west harbour shore for recreational use.
The city has hired a marine engineering firm to report on dredging options, but Harnum doesn't want to leave it at that. He wants to look at alternatives to repeated dredging, including creating an artificial wetland, while also reducing soil erosion along Red Hill Creek and the flow of fine suspended particles in treated sewage discharged just upstream of the basin.
"The very next day after we dredge, it will start filling up again, so we want to look at a long-term solution," he said in an interview this week. "What that is we don't know yet. We might issue a request for proposals to see what the engineering world can come up with.
"Work in the valley (related to expressway construction) will dramatically reduce bank erosion, and our long-term goal is to meet the harbour Remedial Action Plan targets for total suspended solids in sewage effluent, but those are five- to seven-year plans.
"So we've got this wild idea to turn it into wetland. If we filled it more and put plants in, the organic material would get absorbed and we wouldn't have algae. Maybe that would cost $5 million and act as tertiary treatment for the wastewater plant.
"It may be pie in the sky. I don't want to just throw $25 million away, and we have a contractual obligation with the port authority. We said we would not let it impact shipping lanes."
Marilyn Baxter, executive director of the Bay Area Restoration Council, thinks the idea merits further study by all the Remedial Action Plan partners. She notes the city received a SuperBuild infrastructure grant to improve public access to the basin, but that project is on hold because it might be necessary to put dredged sediment on the shore.
emcguinness@thespec.com
905-526-4650
Hamilton Spectator File Photo
The Windermere Basin is filled and sediment is overflowing. Dredging the basin could cost taxpayers $18 million to $22 million.