Although Strawacres comprises of a few acres of land, most of it woodland, it does not have any significant water. No creeks, lakes or ponds. There is a part of the woodland that does have standing water. Here the water table may be close to the surface or there is possibly a hidden spring. Whatever the source is it creates a vernal pond in the woods. In Spring it can cover quite a large area but be relatively shallow and by the end of Summer the water has almost gone leaving just very damp soil. It looks like an important wildlife habitat, so I will write a post on that area later.
The land close to the house had no water for wildlife. What we did have was the rain run-off from the roof of the house and so it was decided to channel the run-off into a pond and not just let the water run away and be allowed to seep into the ground. In this post I will look at the basic design of the pond. In the following post I will show the pond construction and in a third post I will talk about how the it changed in the first year and some of the wildlife that used the pond during that year.
The roof of the main building is a salt box design so the long side collects lots of water and that is captured in a rain barrel and the short roof runs to a downspout. This downspout just pushes the rain down a slope and the water runs away into the land. It was here I had the idea of turning that downspout flow into a stream and causing the stream to fill the pond.
The long roof has quite a catchment area and so can quickly fill the rain barrel when there is rain. The overflow is wasted unless you place a bucket to catch the excess water. The downspout on both the long and short roofs are on the same side of the building so I decided I would capture the overflow of the rain barrel and guide it with piping to the other downspout and feed the surplus rain barrel water into the man made stream.
In designing a pond one has had a few things to consider. The location, size including the depth, water quality and what to build it with. After doing some research you can find plenty of information, some of which is conflicting. In the end I decided to base some of the guiding principles for the pond on ideas provided by Dr Jeremy Biggs who has a blog at jeremybiggs.wordpress.com. The reason for using his advice is his expertise; he is a co-project lead at the Freshwater Habitats Project in the UK and an academic at Oxford Brookes University. In reading his blog I learned a few guiding principles.
- use clean water
- plenty of shallows (don’t dig too deep)
- edges as natural as possible
- don’t worry about shade or nearby trees (which can drop leaves into your pond)
The first point I have no trouble with. I would be using only rainwater so contamination would have to come from the sky or the short distance it takes to travel off the roof to the pond. The shallows intrigued me. I did not want to add fish, but did want to maximize for insects, amphibians, birds and mammals. So the advice to keep it shallow as that keeps the wildlife population high seemed sensible advice to follow. Plus this is Canada and so the pond will no doubt freeze to the bottom, unless I dug it very deep. Since I knew there was nearby area of boggy land, with shallow water, and plenty of frogs (you could hear them) I figured the frogs knew not to hibernate in shallow water and to find elsewhere to survive the cold Winters.
The third point about natural edges seemed logical. I was going to use a pond liner but I wanted to create something that looked natural to me and edge with plants, rocks and other natural substrate. This is where the fourth point comes forward about shade and trees could help as leaves will drift in to the pond, there are just so many trees, but I figured a layer of decomposing leaves at the bottom of the pond would help creatures, providing a soft and natural base. The intended location was near the passive solar panel for water heating so it was in a sunny clear area but as you see from the photographs there were trees nearby.
At the construction phase of a pond one thing you will have to consider is whether or not to use a pond pump and maybe even a cleaning process. I had seen a video of an excellent use of a pump in a wildlife pond to create a stream flowing into the pond by ‘The Rural Gardener’ and I would direct you to John’s blog to see a post about the pond which has a link to the video (look for it at the end of the post before the comments). I decided the downspout stream would be sufficient as a stream and as well I did not want to go to the trouble of adding a solar powered pump to recirculate water. As for cleaning I figured the flushing through of water when it rained would be a good way of cleaning the pond, with only in dry Summer spells there being a risk of algae blooms or stagnancy. I thought I would take the risk.
As for the actual site I had cleared it of major brush for the installation and operation of the new water passive solar panel and so it really was just digging. That would be not so easy as there was a lot of rocks and tree roots. There was some initial digging in Fall 2013, but most of the building of the pond was done in Spring 2014. More in part 2 about the construction of the pond.