Bioengineering test plot in Lions Park – Devon Dispatch

Submitted by Allan Macaulay

You may have noticed the Town of Devons sign in Lions Park recently referring to a bioengineering test plot. Its time to talk about it.

Bioengineering in this context is a process that uses local plant material to stabilize an eroding river or stream bank. If we are satisfied with this process we can apply it to Beaver Loop and other unstable locations around town.

What got this going? This grew out of an environmental plan a group of us did for the Town a few years ago. We started talking and got to know Kristen Anderson a local resident and knowledgeable environmental consultant who now works for Associated Engineering.

Associated Engineering in conjunction with the Town of Devon, Devon Nature Club and Devon Lions Club hosted a two day bioengineering course one day in the classroom at the golf course and one day hands on installing the test plot on the river bank in Lions Park. We used tree stems as the building blocks for the project. The stems were cut on property on the west side of highway 60 with permission of the land owner Qualico Developments. The plant material mostly willow and Balsam poplar was dormant at this time i.e. bud break had not occurred yet. Dormancy and proper handling of the material is key. Its alive and we have to keep it that way. Our instructors were David Polster and Kristen Anderson.

The project was carried out by a group of people including members of the above organizations on April 19 of this year. Several other municipalities and contractors also attended.

Two different methods were used one is called dense live staking at the bottom of the slope and wattle fencing on the slope.

Dense Live Staking

Stakes were cut from balsam poplar and willow. The stakes are 70-100 cm long and 25-50 mm in diameter. We sharpened them and then inserted them into the ground using planting bars and rubber mallets. We tried to get 75 per cent of their length in the ground this is very important. They were placed about 10 cm apart in a random pattern

Wattle Fencing

We then went up the slope installing whats called wattle fencing which consists of more staking in a row these stakes are similar to the ones used in the live staking but they are in a row and about .5 meters apart.

These stakes are used for the support of the fence made of 3-5 m lengths of willow and balsam poplar stems which are about 25-50 mm thick at the base. These long stems are stacked against the live stakes about 6 high and held in place by the natural soils piled against the fence on the upslope side.

These wattle fences were installed 30 cm apart all the way up the slope.

The fence and staking slows runoff down on the slope stabilizing the slope and also holds the bank when the stream or river rises.

All components used in all aspects are living and naturally occurring in this area. Only similar soil from the area is used not bringing in any invasive species or other contaminants. We are taught in the course to only use what is available in the area and natural to the site.

Everything grows and recreates a natural stabilizing process. The project we did was all done by hand.

A beaver proof fence is installed along the river which will have to be maintained from time to time and we are watering the site up to twice a week. There is already lots of growth and its looking good.

Devon participants in the course were, Tanya Hugh, Shawn ONeill, Gord McPherson, Alan Voles, Ted Belke, Shawn Goin, Bill White, Allan Macaulay, Karen Macaulay, Kristin Walsh, plus some other town staff from water treatment plant etc.

We could organize a tour of the site with an explanation if you want contact me Allan Macaulay at albertaspruce@albertatrees.net to set that up.

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Bioengineering test plot in Lions Park - Devon Dispatch