Tag Archives: erosion

Raymore Park’s Beach is back.

Looking north towards the retaining wall.

The Humber makes an almost 90° turn inside Raymore Park and as the current slows down on the inside of the curve, sand is gently deposited on the western bank. When the river level is high, the sand is flushed downstream towards the lake. The sand comes from the Oak Ridges Moraine where it was dumped by glaciers that melted over 12,000 years ago.

The beach in May 2014 from about the same spot showing the old retaining wall.

This is the beach that was used by children from the subdivision destroyed by Hurricane Hazel in October 1954. The beach is a dynamic thing; some years it isn’t much at all; sometimes expanding and sometimes shrinking but the sand will continue to be be deposited for the next several thousand years until there’s none left upstream.

Read more about the beach here and about what washes ashore here.

Not much progress

There seems to be little going on at the retaining wall site these days. It may have to do with negotiations ongoing with the owner at the north end of the wall. If the owner withholds permission for the wall to be completed on the end property, plans will need to be adjusted.

Old retaining wall blocks are stacked along the opposite shore.

Old retaining wall blocks are stacked along the opposite shore.

Part of the

The old retaining wall is being removed in preparation for a newer taller model.

Incidentally, the storm sewer pipe that is visible in the second image is one of hundreds that flow into the Humber. The structure above it may serve to prevent slope erosion.

Some Questions Answered

Work has resumed on the retaining wall and the mystery of the rope stretched across the river has been solved.

It's a lifeline.

It’s a lifeline.

It’s simply something to hang onto if a worker slips into the water accidentally.

Another question answered is what they are going to do with the old retaining wall. Answer: remove it. This week the southerly end of the old wall is being removed and workers are digging  to the bedrock to make a secure foundation for the new blocks.

Digging down to the bedrock for a solid foundation.

Digging down to the bedrock for a solid foundation.

Material being removed from the foundation of the new retaining wall.

Material being removed from the foundation of the new retaining wall.

According to a worker on the site, the work was delayed while trout were spawning but TRCA has given the project the go-ahead and construction has re-started. Apparently when the original wall was constructed, the same company simply accessed the far bank directly and never had to take all the precautions expected of projects on the river nowadays.

Another interesting item; the new wall may not extend to the northernmost point planned as the landowner above that section of wall is worried that the removal of the old blocks and subsequent digging may trigger further landslides. Since the resident in question has riparian rights which go down to the water, they have the right to withdraw consent to construct that last section of wall.

The worker allowed that the project may take until October to complete.

Work slows on Retaining Wall

The retaining wall base has been wrapped in plastic.

The retaining wall base has been wrapped in plastic.

Work has slowed considerably at the site because migrating steelheads (better known as rainbow trout) are spawning in the Humber and rather than disturb their progress up the river, TRCA has ordered a hiatus in work until they complete their spawning. This will depend on the water temperature and will delay the wall’s construction for a while.

More brush was removed from the site recently and the staging area has been expanded, possibly for additional storage space. Further down the river, a mysterious rope has been stretched across the river. The purpose of the rope remains to be determined.

The staging area has been expanded south to include this area.

The staging area has been expanded south to include this land.

Further down the river, a rope has been stretched across the Humber.

Further down the river, a rope has been stretched across the Humber.

The rope across the humber.

The rope across the Humber is beginning to catch driftwood.

Looking north to the temporary bridge.

Looking north to the temporary bridge.

Retaining Wall Update April 18

At first glance nothing much seems to have changed from last week.

At first glance nothing much seems to have changed from last week.

Last week, the project took a major step forward with construction of the wall foundation to the south of the bridge. An equal length of foundation will be constructed upstream and then the wall will be added on top of that.

The retaining wall foundation stretches along its southern length.

The retaining wall foundation stretching along its southern length.

At least the question of what to do with the existing blocks is answered. They will simply be kept in place behind the new wall. With the narrowing of the existing riverbed, I wonder what the erosion implications will be on the western bank.

Retaining Wall Update April 12

It’s truly astonishing seeing the scope of this work and the seemingly glacial pace at which it is trundling along. As of last weekend, not much has changed except that the new bridge has had its eastern abutment extended to the far bank.

The bridge with its extended abutment.

The bridge with its extended abutment.

The result of the new abutment is to constrict the river at this point and warnings have been placed south of the bridge about the dangerous flow.

A close-up of the abutment.

A close-up of the abutment.

The extended abutment from downstream.

The extended abutment from downstream.

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The faster flowing water downstream.

 

Retaining Wall Update March 23

Materials are still being amassed on the staging area and while it looks as if the blocks are all set to go, the bridge decking has arrived along with large amounts of limestone rubble and bagged gravel. Actual construction shouldn’t be long in coming.

Limestone rubble at the south end of the site.

Limestone rubble at the south end of the site.

 

Limestone rubble stored by the blocks at the north end of the site.

Limestone rubble stored by the blocks at the north end of the site.

 

Blocks with limestone rubble.

Blocks with limestone rubble behind the forklift.

 

Bags of gravel.

Bags of gravel.

 

Bags of gravel stored by the staging area entrance.

More bags of gravel stored by the staging area entrance.

 

Steel plates that will form the decking of the bridge.

Steel plates that will form the decking of the bridge.

 

Another view with the bridge decking in the foreground.

Another view of the site with the bridge decking in the foreground.

Retaining Wall Update March 16.

Work continues unabated at the site and the size and scope of the job is becoming apparent. More and more blocks are piling up in the staging area and the components for a temporary bridge that will straddle the river have arrived. The bridge will be placed across the river and support the crane that will build the retaining wall. Each block is labelled with its weight which is vital knowledge for the crane operator. The bridge will be re-positioned along the banks as required.

The project was originally scheduled for completion for the end of March but clearly there is still a massive task ahead.

Interestingly, the second photo was taken on February 29th and in the top right of the image can be seen the very small amount of ice pushed ashore during the thaw. This is the smallest amount of ice I have seen in years and quickly melted.

Blocks are piling up awaiting placement.

Blocks are piled up awaiting placement.

 

Each block is labelled with its weight.

Each block is labelled with its weight. Notice the small amount of ice freshly deposited as a result of the thaw.

 

The bridge.

Girders that will be used to make a bridge to straddle the river.

 

The bridge and blocks in the background.

The bridge girders and limestone blocks in the background.

 

The bridge platform.

What looks like the beginnings of an abutment on which the bridge will rest.

Retaining Wall Update: Blocks Arrive

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The official diagram showing the working area of the project.

Truck after truck of old brick rubble came trundling into the park last week to consolidate the staging / stockpiling area. All of this material will eventually have to be scraped up and carted off again; probably late next month. No doubt this will have added substantially to the cost. Meanwhile, big blocks that will form the new retaining wall have arrived.

Mild weather has brought new problems, this time for pedestrians and cyclists; mud. This mud is unavoidable for anyone wishing to travel past the construction. It might be helpful if the construction crew – ever vigilant for pedestrians (wishing to stay clean) straying through the paved area – could spread some wood chips to make life easier and cleaner for people.

Large machinery resting on the base.

Large machinery resting on the base.

 

A close-up of the base.

A close-up of the base.

 

Blocks for the retaining wall are waiting to be installed. The fence is about 6' high.

Blocks for the retaining wall are ready to be installed. The fence is about 6′ high.

 

The blocks are natural stone.

The blocks are natural stone and should last a few years!

 

This is the treacherous route for people moving past the construction.

This is the slippery quagmire for pedestrians and cyclists. Wood chips will help greatly here.

 

Cyclists have obviously made their mark.

Cyclists are making their mark.

Update: Wood chips were quickly applied to the quagmire making things easier for the pedestrians who must pass through.

Work begins on Humber bank stabilization and sewer rehabilitation.

More than a decade ago, the owner of a house on Sykes Avenue in Weston suddenly lost several feet off the back end of their property. The house overlooks a sharp curve of the Humber River as it turns to the south. During April rains in 2004, the rear of the property abruptly vanished along with several mature trees and other vegetation. Luckily nobody was standing near the edge.

Shortly after the landslide in April 2004.

Shortly after the landslide in April 2004.

Panorama view of the bank as it looks today.

A panorama view of the bank as it looks today. Note the current retaining wall and the precarious position of the tree on the right.

That summer, the fallen trees actually went into leaf and remained in place for most of the season but were eventually washed down the Humber. What caused the erosion? Who knows; it probably didn’t help that each autumn, the owner at the time drained the pool over the top and into the river. The likely explanation is that the slope was simply too steep to withstand the shearing forces and nature adjusted the angle. TRCA is responsible for erosion control and has a handy guide for those ‘living on the edge’. It must have been painful to update the property deeds to reflect the new reality. After this event, the owner put in some vegetation and other stabilization measures but by then the rot had started and moved downstream taking chunks of other back yards into the river.

A retaining wall of sorts is already in place, built in 1981 and it has been high enough to provide ‘toe protection’ for most flood events. Unfortunately it wasn’t tall enough to cope with major events such as the storm of July 2013.

After extensive study, TRCA has decided that in order to stabilize this stretch of the Humber, a 6.5 metre tall ‘replacement armourstone wall’ and stabilization measures need to be put in place on 170 metres of the east bank before more land disappears downstream.

Raymore Park entrance.

Raymore Park entrance. Notice that the pathway and direct footbridge access is blocked to pedestrians. This could have been avoided by fencing off a narrow gap on the left.

Looking south from the parking lot.

Looking south from the parking lot. The trail resumes further down.

Since construction from the top of the east side is impossible, the plan is to access the wall through Raymore Park.

Unfortunately the solid winter ground from the bike path to the river expected by the construction crew has failed to materialize (so far) and a steady stream of trucks has been offloading fill onto the site in order to construct a stable road down to the river.

Sadly dozens of native trees that were planted several years ago have been removed from a surprisingly large area. Presumably these will be replaced but this will delay the expected native canopy planned for this section of the park.

The new road under construction leading to the river. Notice the clearance of all trees and shrubs.

The new road under construction leading to the river. Notice the clearance of all trees and shrubs.

Another view showing the extent of the clearance.

Another view showing the extent of the clearance.

In the meantime, pedestrians are having a messy time getting access to the footbridge from Raymore Drive, the continuation of the path further down the park and there are questions regarding the replacement of trees and shrubs lost when the land was cleared.

According to the leaflet delivered to homes in the area, the work is scheduled to be completed by the end of March and restoration of the land will take place in the fall. Projected cost: up to a maximum of $250,000.

At the same time, more sewer rehabilitation work is ongoing along the Humber that will necessitate further tree clearance along the path of the sewer line between now and the end of March and this will extend along the river between Raymore Drive to well past Eglinton. The City of Toronto has more information here.

Later this spring will begin the construction (if given final approval) of the proposed leash free zone (Many dog owners seem to have declared Raymore Park leash free already). This will bring even more heavy equipment through the park. A final meeting is scheduled for February 25th at 6:30pm in Westmount Junior School, 95 Chapman Rd. Councillor Rob Ford will be in attendance.