Chester Springs Marsh - Then and Now

Chester Springs Marsh as viewed looking south from the Bloor Viaduct, about 1996


Chester Springs Marsh, 2008

Picture comparison: the mowed grass is completely replaced by trees and shrubs with some bits of meadow in between. A path circling the wetland is now totally obscured. The only indication of it now is a garbage can placed at the northern entrance point (top end of the graffiti). The red tinged sumac grove in the lower right of the picture is still there although there is a patch missing from the middle. This was created by a homeless encampment which was recently abandoned.

It's been 12 years since the Task Force to Bring Back the Don created a new wetland in the Lower Don. Chester Springs Marsh was the first major project of the Task Force and it has influenced restoration efforts in the Don Valley ever since. As you can see from the original photo, it was built in a former grassy meadow with just a few large trees and some shrubs along the river bank. The photo also shows a few saplings new planted.

Today those saplings have grown to heights of 10m and have turned the grassy meadow into a forest. The marsh is now totally obscured by these trees as the new photo shows. The reality is that the marsh now contains very little water and the area is now more of a wet meadow. Shrubs are starting to encroach on this space and the wetland that it started out to be is fast disappearing.

How did this happen? There are a number of reasons for this some of which were not foreseen in the original design. The marsh was meant to have continual water which would be topped up periodically by high water from river floods. However the channel that connected the marsh to the river quickly silted up so that the refresh now only occurs during extreme high water events. This means that any water that gets in likely dries up before the next refresh.

Another problem was what was underneath. The marsh was built on a former landfill and its excavation exposed some of the rubbish buried there. Some it was stuff like old pieces of pottery and other turn of the century knickknacks. When people discovered this, a flock of scavengers descended on the site digging pits looking for buried treasures. This activity inadvertently created wells which drained the marsh.

So rather than a marsh we have more a meadow that gets occasionally inundated. This is not necessarily a bad thing but there are other issues with the marsh. One of them is the problem of non-native species that have invaded the site. These include garlic mustard, dog-strangling vine, Japanese knotweed, creeping thistle, and teasel to name a few. These plants are starting to dominate the understorey and are crowding out native plants. There are some non-native trees including Siberian elm, black locust and Manitoba maple but they are not yet crowding out the native trees. The native trees are doing quite well and they include a couple of uncommon species such as hackberry and red mulberry.


CSM as viewed from the side. The wetland is no longer visible. Small trees such as willows and shrubs such as dogwood are no encroaching on the area formerly occupied by the pond.

What is the future for the marsh? That is still up in the air. The Task Force has requested a study be performed on the marsh but they are taking their time. The results of the study could recommend that nothing be done or that some level of management or remediation be performed. Whenever that study is completed, I'll let you know the results.

New Trails in Crothers Woods

This announcement has just come from the city:

New Intermediate Single Trail in Crothers Woods Now Open

Parks, Forestry and Recreation's Sustainable Trails Initiative is pleased to announce that a second section of multi-use intermediate single trail in Crothers Woods, near the Loblaws trailhead, is now open. In total, 990m of new sustainable trail have been built with 1137m of degraded and eroded trail closed and restored. Please respect all new trail closures and areas designated for forest regeneration. The use of closed trails and the continued degradation of restored areas may lead to future trail closures. Feel free to send us any comments or feedback you may have about the new trail.

A special thank you to IMBA Canada, Sustainable Trails, Urban Forestry Associates and the Toronto Region Conservation Authority for all of their hard work and assistance on building these new trails. A special thank you to Don Watcher (natch), a long time supporter and steward in the Don watershed, who volunteered over 50 hours of his time to help us complete the new trails. DW's expertise in ecological restoration and enthusiasm for our project was a big help.

Erosion Control Update 3

Site A embankment in good shape

I visited the Erosion Control Site on July 7. It is now into July and no further work has been done. Admittedly, July is usually a period where there is less rain and this July is on track to become one of the wettest on record. Unless August starts being a lot drier it may be September or October before the work gets done on Site B. The main problem is access to the downstream site requires a temporary river crossing to be constructed. This can't happen if the river is flooding once per week.

As to the completed work I noted a few observations. The dogwood and willow twigs that were placed in the Site A embankment have actually sprouted leaves. At least one of them has produced flowers. The bank itself has held up well even after some moderately heavy rainfalls. Debris in places shows that water levels have come about halfway up the bank.


Dogwood cuttings (Cornus spp.) are sprouting vigorously


Debris litters the embankment which indicates that recent storm events have pushed water levels halfway to top of bank.

At the downstream end the river is doing something interesting. Adjacent to the rock lined area is a clay embankment. The river has started to scour this heavily, eroding it faster than just further downstream. Water may be speeding up as it passes over the rock creating an eddy as it leaves the rocks and hits the natural surface. This may require some additional bank tinkering to reduce this effect.


Clay embankment shows additional scouring at downstream end of Site A

Some plantings have been done at the top of bank. The plants are looking a little forlorn since any mulch has washed away. Some additional maintenance may be required although they have certainly been getting enough water. The adjacent railway embankment is a total loss in that it is completely covered with Dog-strangling Vine (Cynanchum rossicum). Some serious treatment regime is needed here or the restoration will be overwhelmed by DSV in a few years.


Some plantings have been done as part of the restoration plan.

Dog-strangling Vine accounts for about 95% of the ground cover on the railway embankment.

Wetland Site Inspected

Sign posted for proposed wetland. Work is supposed to start in fall 2007 but nothing has been done yet.

I decided to investigate the proposed site of the new wetland that I blogged about a couple of weeks ago. It is located just west of Victoria Park Ave. in Taylor Park. The site is relatively flat except for some slightly raised mounds that are mostly planted with trees. The flat area is almost entirely covered with Cattails (Typha ssp.). Behind the mounds to the north is a shallow swale that is almost covered with grass. I dug a small test hole here and the earth is very muddy just below the surface.

I'm no expert on wet meadows but this doesn't look like a well functioning habitat. The Cattails form an almost complete monoculture. There is one native and one non-native variety which are hard to tell apart. Both of them are considered to be invasive in some habitats. My conclusion is that this is the case here. The proposed wetland will involve removing most of the Cattails and replacing them with a wetland habitat that will have considerably more diversity.

The unknown factor is whether the ground water source will be active enough to keep the pond feature wet. Once it is excavated water will flow in but evaporation will be increased. Whether the groundwater source can keep up with the loss is an unknown quantity. It may take a few years before a balance is reached. It will certainly be something to keep monitoring.


Nothing but Cattails are growing on this wet meadow

New Wetland Proposal

Wetland Design Scheme (click to expand)

The Don is getting a new wetland this fall. Just west of Victoria Park Ave. in Taylor Creek Park is an open field that gets very wet. There is no apparent water source so it is likely that the water table is very close to the ground in this area. This is an important project for the Don Watershed. Only about 0.2% of the original wetlands have survived. Most have been lost to agricultural and urban uses. Anytime that this trend can be reversed it is a positive development.

Construction is due to begin sometime this fall. Backhoes will be brought in to excavate the pond which will be about 1.5 m at its deepest point. In the spring, planting and other landscaping will be started. As with any new project it will take a few years before it starts to look like anything substantial.

Feedback from local environmental groups and residents has been mixed. Friends of the Don East are generally supportive of the project yet rival group Taylor Massey Project supports it in principle only. In a letter to the city staff, they outline their reservations which appear to be centred around the fact that they weren't consulted. They claim not to have have seen a detailed design (see above) nor are they aware of the budget (about $300,000). TMP wanted a site visit as well but didn't get one. They are also concerned about fluctuating water levels.

The East York-Riverdale Mirror has published an article on the wetland. In the article local councillor Janet Davis said that a public meeting will be scheduled next month with environmental stakeholders to review the project. A local resident, Alyssa Diamond is opposed to the project mostly because she doesn't want a wetland behind her house. She says that it would be a source for mosquitoes. What she doesn't realize is that a functioning wetland would be less of a source for mosquitoes than the current wet meadow. She also says that a wet meadow provides valuable habitat. This maybe true but most of the habitat that a wet meadow provides is also available in a wetland. A wetland also provides a more diverse range of habitats including a place for fish, amphibians and reptiles. If you were to rate habitat value on a scale of 1-10 a wet meadow would be about 4-5 but a wetland is a solid 10.



Location of wetland site

St. Clair Ravine Planting

Planting a grassy slope in St. Clair Ravine Park

I attended a planting this morning in St. Clair Ravine Park. Sponsored by Friends of the Don East, its purpose was to extend the forest along a grass covered slope. The parks people approved this location because kids toboggan on this slope and there is a fence covered culvert across the path at the bottom of the slope which they could crash into. The planting here might prevent that. The neighbours at the top of the hill were a little non-plussed. They seemed chagrined that they might lose their view. In about 10 years or so, they'll appreciate the additional privacy.

I didn't actually plant anything. I spent the entire time filling mulch buckets. We got rid of an entire mulch pile which is quite an accomplishment.

FODE's rival group, the Taylor Massey Project will be hosting a planting in the same park, just a little east of here, next Saturday, Oct. 27.


All the plants in the ground, Choke Cherry, Trembling Aspen, and Staghorn Sumac.

Donora Ravine Restoration

Map of Donora Ravine

Donora Ravine is a small place as ravines go. But for some local residents it is now a big issue. Late last year the city began a restoration project of the degraded site. The controversy began when the city cut down all the Norway Maples (Acer platanoides) surrounding the ravine. While this is an important first step in the restoration process, cutting down mature trees is a touchy subject for city residents, especially if they don't realize the impact this species has on the natural environment.

Norway Maples are an introduced species that are commonly planted as a street tree. They grow fast, produce a dense canopy of shade and can tolerate a variety of urban conditions, ie. salt tolerance, drought resistance, and soil compaction. They also produce large volumes of seeds that readily sprout everywhere including our ravine parks. Left unattended they can out-compete the slower growing Sugar Maple (Acer saccharum).

While the result may be a little unsightly in the short term, in about 10-15 years the woodland will re-establish, this time with native species. Friends of the Don East have been busy this year planting native trees and shrubs. Already there are signs of abundant understory growth. The stumps of the maples were left in place because these will provide valuable habitat for tree dwelling animals including Raccoons and Wood Ducks (Aix sponsa). Woodpeckers also feed here on insects living beneath the bark.

In order to educate the public, the city erected an interpretive sign that describes the restoration project and its importance to the natural environment. It will be interesting to watch this site mature over the next couple of years.


View of ravine taken December 2006. Viewpoint is arrow #1


Donora Ravine, 10 months later. Viewpoint is arrow #2


Father and daughter read intrepretive sign beside ravine

Cedarvale Park Restoration

A former grassy ditch gets a makeover

I went to a planting last Sunday in Cedarvale Park. Cedarvale Park is just south of Eglinton West Subway station and sits atop the Spadina subway line. Most of the park is grassy field, underused except by dog walkers and a nearby cricket pitch. The location of the planting was a ditch formerly lined with grass. In the spring it fills with meltwater but is dry most of the summer.

This project was started by ex-city employee Trisha Kaplan-Freed who has since moved out to Vancouver Island. Her efforts to make the most of poor habitats like this in Toronto will be sorely missed. The ground is some of the worst digging I've encountered. Just underneath the grass the soil is heavily compacted and as hard as concrete. I expect that there will be a low survival rate unless these trees and shrubs are watered and tended for the first few years.

Still it is a worthwhile project. Hopefully in 5-10 years enough material will survive to start providing habitat for birds and small mammals. Perhaps I will make annual treks out here to check it's progress to see if my prediction holds true.


Schematic diagram of the project


Don Watcher manages to plant eight Eastern White Cedars (Thuja occidentalis) in hard packed soil.

Fall Planting Season has Started

The city has posted a schedule for tree planting this fall. There are 12 events including 10 tree plantings, one bird banding, and one trail building workshop. Eight of the events are located in the Don River watershed, one in the Highland Creek watershed, one in the Rouge River watershed and two on the Toronto Islands.

I hope to get out to a few of the events and take some pictures. If you come out to a tree planting you may be featured in an upcoming Don Watcher post!

Spring 2007 Planting Events

The city has published its summary of spring planting events. You can view the two page PDF here. This includes events city wide including the Don. I will continue to summarize weekend events on Thursdays for the next month or so.

Tree Planting at Riverdale Farm

Tree Planting at Riverdale Farm

This year's spring planting at Riverdale Farm was a lot sunnier than last year's event so it went a lot quicker. Hordes of children and their parents showed up this year so the 150 odd plants went into the ground in less than an hour. We needed to check all the plants with a tug test because the ground was a little soft in places and some of the trees were not firmly anchored in the soil. This was just one of many plantings that are happening around the city for the Earth Day weekend.


Ginger and her piglets

After the tree planting I strolled around the farm to see what else was happening. In the pig pen, "Ginger" was busy feeding her seven newborn piglets. The spring time is when many of the animals give birth to new broods. The farm is a hidden treasure in downtown Toronto that benefits many children and educates them about farm life.