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Sunday, October 21st 2007

18:35

A Trip to the Sawmill Creek Constructed Wetland

Since the weather was so great today we decided to take the quadracycle to the newest “park” in our city. I call it a “park” instead of a park, because it isn't exactly a park. I'll explain that statement as we go along here.

The Sawmill Creek Constructed Wetland is not very far from where we live in south Ottawa. In fact we have been there several times already, on foot and by bicycle, but not by quadracycle. The reason that we haven't had the quadracycle there is “access” which is remarkably poor.

History

The City of Ottawa had a contractor build the Sawmill Creek Constructed Wetland over the last three years. The original budget was $8M, but the final cost was $13M. That is a lot of money and makes the Sawmill Creek Constructed Wetland one of the largest projects that the city has completed in recent years. Why spend all that money to build a 400m X 2000m “park”?

That is because it isn't a park.

Location

Sawmill Creek Constructed Wetland is located between Airport Parkway on the west side, the OC Transpo O-Train track and Transitway on the east side, Walkley Road to the north and Hunt Club Road to the south. There are no access roads or driveways to it and no parking lots, in fact no real connection to the outside world.

Purpose

The Sawmill Creek Constructed Wetland was built primarily as a storm water run-off processing facility. The south part of Ottawa was, of course, once agricultural land and bush. These types of landscapes are pretty good at absorbing rainfall and produce only small amounts of runoff. However the suburbs that now occupy the area are another matter. Urban landscapes in general produce lots of run off from rainfall. The reason is pretty obvious – they are largely asphalt and concrete, not to mention building roof area and that means that little rain water gets absorbed into the water table, instead it runs into the drains. Until the Sawmill Creek Constructed Wetland was built the rainwater all collected and ended up eventually in the Sawmill Creek itself. The Sawmill Creek is pretty small and so when there was substantial rainfall the result was flooding and drain backs ups. The longer term problem was silting up of the creek, because it really isn't big enough to handle the level of silt that the rainwater contains.

Where does all the silt come from? That is a another by-product of urban landscapes. Silt is made up of sand that it poured on the streets in the winter (along with salt, but that is a another story), plus the sand run off from ornamental landscaping and other origins. Urban landscapes produce lots of silt, along with lots of rainwater run off.

The Sawmill Creek Constructed Wetland was built primarily to solve the Sawmill Creek flooding problems and also as a de-silting facility. To accomplish this the facility is designed with four ponds. Storm water from all over the south of Ottawa is piped into the south end of the facility and runs northward. (See the Map)

Operating Concept

Run off water first comes to the fore bay, which allows larger silt particles to settle to the bottom, before the water passes over a height regulation dam to the main cell. In the main cell the lighter sediment is settled off and sunlight is used to kill off bacteria.

From there the water passes through a narrow channel into the wetland. This area has been planted with reeds and bulrushes and is much shallower than the previous two ponds. The wetland area is designed to absorb many more contents of the water and also to provide a home for waterfowl, hence the name, Sawmill Creek Constructed Wetland. The waterfowl habitat is its secondary use.

At present there are only some Ringbill Gulls using the place, but in previous weeks Lesser Canada Geese were there in some numbers, along with crows and blue jays. Last week I saw a Blue Heron there, although I don't think he was impressed with the lack of fish.

After the wetland the rainwater flows through a culvert, under the railway east-west tracks and into the outlet pond. From there it flows into the Sawmill Creek, just near Home Depot and then into the Rideau River, the Ottawa River and the St Lawrence River, before it reaches the Atlantic Ocean.

The whole Sawmill Creek Constructed Wetland area actually runs just west of the South Keys monster-mall, although the mall blocks pretty much all view of it from the east side.

Recreational Use

The third listed use of the Sawmill Creek Constructed Wetland is “recreation”. This is a bit odd. The builders did construct a very nice 10 foot wide asphalt pathway that circles the south three ponds and even has a spur that runs under the Walkley railroad bridge and allows pedestrian and cycle access to the outlet pond, although the pathway just dead-ends there.

People do use the facility for walking and biking, but few people know it is there. I get the impression that it is run by the City's public works division and not the parks department.

The Sawmill Creek Constructed Wetland probably meets its mandate for storm water processing and waterfowl habitat, but it really needs some improvements to make it a useful facility for people.

Access

First it needs some access. Right now you can walk there, up the on-ramp to Airport Parkway from Hunt Club Road and then cut into the Sawmill Creek Constructed Wetland down an embankment or rock-hop across the inlet creek. You can walk or bike further north on Airport Parkway and then enter at the sort of mud entrance, although there really isn't anywhere to park a car there. At the north end there is a dirt driveway, but no parking area there, either. Most of the places that look like they would provide access or did during construction have been ditched.

There is a foot route from South Keys Mall, but it is via the Transitway station and then a tunnel under the tracks and apparently few people know about it, except those who own spray paint cans.

Some improvements to provide some parking would help people get to the facility. Even better, a link to the excellent pathways inside the Sawmill Creek Constructed Wetland from the outside is really needed.

North end

The north end of the internal pathway, as mentioned, just stops dead at the outlet. Just a kilometre north is another recreational pathway that cuts from a housing area to Hogs Back, this would be great to link up to and would provide a really superb bike route for cyclists to get from Hunt Club to the Colonel By Drive without going on Airport Parkway, but requires running about one kilometre of additional pathway along the Sawmill Creek north.

Facilities

As mentioned the Sawmill Creek Constructed Wetland has some great pathways and also has some interpretive signs. It really needs some benches for people to sit on and some garbage cans to encourage people not to litter. Littering has been a problem.

Publicity

The Sawmill Creek Constructed Wetland could also use some notice that it exists. The signs installed are all well hidden inside the facility and there is no indication from any of the bordering roads that it is there. I could see would make sense if it wasn't intended for people to use, but the expensive pathway and interpretive signs are a dead give-away that people should use it! Besides the interpretive signs say that it is intended for recreational use!

Quadracycling

We enjoyed our quadracycle ride around the pathways this morning – it really is a great way to get around town and see new things like the Sawmill Creek Constructed Wetland. Other than one pedestrian and one small group cycling there was no one there, except a dozen or so Ringbill Gulls. Access wasn't great – we pedelled down Hunt Club and up the ramp onto Airport Parkway, which was fine. Then we had to cut to the pathways inside the Sawmill Creek Constructed Wetland by cutting through the mud area that serves as the closest thing to a makeshift access. With the recent rain we have had it was soft and wet. We later exited the same way.

Winter?

It will be interesting to see what happens to the facility over the winter. Perhaps we can XC ski there if no one plows the pathway or dumps salt all over it. I imagine the water will all freeze and the birds will be gone until springtime.

Conclusion

It is great to have this new “sort-of-park” in the neighbourhood. With a few minor improvements (compared to the initial cost) it could be a truly great recreational facility, for quadracycling as well as for biking and walking in. The water fowl seem to be enjoying it.

Have a look at our complete gallery of photos of the Sawmill Creek Constructed Wetland.

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