Sunday, December 23, 2007

Erosion Control Class EA

Project Site Location. This is very close to the "Rainbow Tunnel" which is visible from the northbound DVP.

This fall I participated in a Class Environmental Assessment Project on the East Don just south of Lawrence Ave. East in the Charles Sauriol Conservation Area. The purpose of the EA was to analyze options to control erosion along a section of the river that is adjacent to a CN railway embankment. The erosion problem manifested itself during the August 19, 2005 storm that deluged parts of the Don Valley. This was the same storm that blew out Finch Ave. West where it crosses Black Creek. That repair cost about $30 million.

In the case of the this site the erosion wasn't as critical but the TRCA realized it was an impending problem, thus this project was initiated. Part of the Class EA process is to obtain community input into the project. I attended three Community Liaison Committee meetings where we looked at different options.

There were two sites of interest. Site A is about 120 m long (later reduced to 90 m) and about 5-11 m from the CN railway embankment. Site B is about 75 m long but is much closer to the embankment. We considered three different bank treatment options, soft stabilization, hard stabilization, and channel realignment. Moving the CN railway line was not considered as it was too expensive. Channel realignment was also discarded as being too expensive/intrusive. Hard stabilization methods such as lining the bank with crib walls or stone were looked at but discarded because they would actually increase flow rates, effectively transferring the problem downstream. They would also be very poor for aquatic habitat.

Riverbank at Site A. Note the undercutting of vegetation on the left. The brush layering technique will cut away the top of bank at a 2:1 angle and infill with soil and plant cuttings.

Site A looking downstream. The moss covered bank in the middle of the picture was removed from Site A because it is a hard laminate clay which won't erode as fast as the sandy soil where I was standing for this picture.

That left soft stabilization methods. Everyone agreed that this was the way to go and was relatively low risk (all except the rep from CN who basically wanted a zero risk cement wall built). The two options chosen were live brush layering for Site A and vegetated riprap for Site B. Live brush layering consists of soil anchored with a biodegradable mat and plant cuttings imbedded in the mix at 10 cm intervals. The plants, Pussy Willows and Red-osier Dogwood, will grow quickly and their roots should provide an anchor for the soil. Vegetated riprap is similar but contain layers of stone intermixed with soil and vegetation which is more appropriate given the steeper nature of the bank.

My main concerns were construction road access and cleanup once the project is complete. Ten years ago, a similar project failed to complete a cleanup leaving the access road and staging area in place even though it was promised. This discussion is now included in the report. I also received a commitment for post construction monitoring of the site as well as watering of the plant cuttings in case of another dry summer.

Construction is set to proceed in late February, 2008 and be completed by the end of March. I hope to get to the site once or twice to monitor progress. There is still a 30 day viewing period for the report ending January 21, 2008. Copies of the report can be viewed at the Urban Affairs Library at Metro Hall or the library at 888 Don Mills Rd.

Friday, December 21, 2007

Don Valley in the Blogosphere

I've been busy with exams and Christmas stuff. What with the big winter storm I haven't been able to get into the valley. I'm working on a couple of longer posts which I hope to have up soon. In the meantime here are a couple of links to other blogs that have posted Don pictures.

A Walk on Earth posted pictures of the old Eastern Ave bridge south of Queen St. This blogger is also a cross country skier who took some shots from Taylor Creek Park while it was still good to go for a run.

Dodgeville posted a picture of the frozen pond behind the Science Centre. Apparently some enterprising skaters made a natural rink which the city quickly put the kibosh on (No one in legal services skates). There is also an interesting link about a forgotten section of Don Mills Rd before it's Don River crossing was expanded. Also some musing while taking a lunch time walk through E.T. Seton Park.

Tuesday, December 11, 2007

Charles Sauriol Article Contains Factual Errors

I came across an article in the East York-Riverdale Mirror written by Joe Cooper. It is entitled "The memory of Charles Sauriol must be preserved at Todmorden Mills". It talks about Sauriol, his Don River legacy and his connection with Todmorden Mills. Cooper wrote the article to emphasize his position that the Don Station now ensconced at Todmorden Mills should not be relocated to the Roundhouse down by the Skydome.

I am all for writing about history but he makes some important factual errors that I think are worth correcting. Last year I wrote Wikipedia articles on Charles Sauriol and Todmorden Mills so I know a few things about these topics.

Here's a rundown on the mistakes.

1. Cooper states that Sauriol formed the Don Valley Conservation Authority. It is true that he formed an environment group in 1949. However, it was called the Don Valley Conservation Association. The Don Valley Conservation Authority was formed in 1946 by the province through the Conversation Authorities Act. They have the same initials so it can be confusing.

2. Cooper claims that Sauriol's cottage in the valley was demolished due to the building of the Don Valley Parkway in 1961. In compensation he was made a member of Metro Toronto and Region Conservation Authority (MTRCA). Sauriol actually joined the Don Valley Conservation Authority as a board member in 1954. In 1957 it was merged with other local conservation authorities to become the MTRCA (now the TRCA). Sauriol retained his cottage until 1968. Part of his 40 hectares was expropriated for the construction of the DVP but he stayed on his land for a further seven years.

3. The Don Station was located at Queen Street further south in the Don. In 1969 CN decided to add another track to the Don line and the station was in the way. Sauriol raised some funds locally to relocate the station to Todmorden Mills. As far as I know the TRCA had nothing to do with it. The station itself has no connection to East York. I think Sauriol placed it at Todmorden Mills because it was convenient to do so. Cooper also wrote an earlier article about the Don Station on July 26, 2007. He stated that the Belt Line Railway went through Todmorden Mills. As far as I know Todmorden Mills has had only road connections. It has never been serviced by railroad and has never had any kind of railway depot or station.

Cooper also got a few dates wrong concerning True Davidson, mayor of East York but they are minor. Cooper's main contention is that the Don Station is closely tied to East York heritage and should remain at Todmorden Mills. If you know your history you'll realize that the station has little to do with East York. Its only connection is that it has been located at Todmorden Mills for nearly 40 years. Clearly it is part of Toronto's railway heritage. If the Roundhouse is ever restored as a railway museum than this is where it should be located.

Friday, December 07, 2007

Stroll in the Park

Moccasin Trail Park in late October

What with all the dissing the Don River is getting this week, it's good to see some positive articles about the Don. Shawn Micallef of Spacing Magazine wrote a story about Moccasin Trail Park in the southeast corner of Don Mills. Shawn is right - it is a beautiful place. I was there a couple of times this year, just passing through to get to other places, but well worth a visit on its own merit. I haven't been in the winter, I imagine it looks a little different then my last visit.

How to get there: Moccasin Trail is a road that heads southeast off of The Donway East just east of Don Mills Rd and south of Lawrence Ave. East. Drive all the way to the end and you'll find the park entrance. Drive down the winding road. It ends in a parking lot.

Wednesday, December 05, 2007

Emerald Ash Borer Arrives in Toronto

We knew it was on the way but didn't expect it to get here so fast. An article in the Toronto Star says that the Canadian Food Inspection Agency has found some ash trees infested with the Emerald Ash Borer (Agrilus planipennis) in the Highway 401/404 area. This is in the northeast section of the Don watershed so it definitely concerns us.

I remember attending a seminar last year on forest pests and the talk was about the Asian Long-horned Beetle (Anoplophora glabripennis) which infested a large area in northwest Toronto. The Emerald Ash Borer had been found in Windsor and was advancing steadily east. The thinking was that the beetle would probably arrive in Toronto in about 5-10 years so it's a surprise to find it so soon.

Once it infests a tree it eats into the sapwood. This is the part of the tree that transfers water and nutrients to the top of the tree. When this is gone the tree dies quickly. If this finds its way into the Don Valley this could have serious implications for our forests. Ash trees constitute about 10% of the trees in our forests so this could have a big impact on our forest canopy.

Efforts are underway to contain the outbreak but there is little anyone can do. They are very difficult to detect. As an introduced insect it has no natural enemies and no pesticides are known to kill it. Unless a miracle fix is found, we may be looking at a permanent change to our forest.

Tuesday, December 04, 2007

Don Slagged as Ontario's Worst River

The Ottawa Citizen published a special report this past weekend on the state of Ontario rivers (reprinted on the Ottawa Riverkeeper's website). Included was a report that labels the Don River as Ontario's worst river. It scored 34.8 out of 100 on a water quality scale, the lowest in Ontario (as a comparison, the Rideau River received a "fair" rating of 74.2). The article is rife with quotes from local Don experts who all agree the river has gone to hell in a handbasket. Problems such as urbanization and sewage overflow from antique sewer systems are cited as major problems.

Of course the Ottawa River is nothing to write home about. Communities along that river still dump treated sewage into the river and they have a problem with combined sewer overflows just like the Don. Surprisingly many communities also rely on the river as a drinking water source (nobody I know still drinks from the Don :( ).

There were two additional articles in the special report, "Grave Waters", and "What's Not Measured". Both articles touch on the major issues affecting many southern Ontario rivers, namely stresses from agricultural and urban runoff are heavily impacting water quality everywhere.