A few hundred ml of rain in a short time is not unusual here on the Sunshine Coast, and extreme rain events are more and more common. Tom had noticed in past heavy downpours, that our existing top swale was almost breaching. The task of this top swale is to catch, hold and distribute water from upper parts of our property, as well as functioning as a dam overflow. He decided that we would need another swale to share the load of the existing one, and the best location for this would be on the opposite side of the dam.
As part of our one week Earthworks course, we brought in a heavy excavator to dig this large swale. Unfortunately the location of the swale meant we had to dig through regenerating forest, but we will intensively plant out the swale to prevent erosion issues and re-establish growth in the area. The idea behind the swale is that the existing swale’s load will decrease by about 50% by spreading out the water. This will also bring more water onto the other side of the property, where it will encourage existing regenerating forest growth and will prevent flooding issues in the student camping and common areas.
We were lucky to have some rain straight after having dug the swale, so that we were able to immediately sow some ground cover and support species seeds. By the time the next big wet comes we should have some nice growth on the swale to prevent any erosion. Over the next few weeks we will plant out more support species and fruit trees, so that the swale mound will be a food forest as well. There are some steep areas on the new swale, so quick planting out of the swale is absolutely essential, to prevent breaches of the swale mound in the next big wet.
Both swales provide an overflow for the dam, and the overflow water runs back into the existing creek. The existing swale’s overflow water runs along the road in order to get to the creek, so by adding this new swale we will minimise road damage done by any overflow waters as well as the new swale’s overflow water deposits directly into the existing creek.
We are excited to start planting out more fruit trees to create another food forest area on our property, and even more excited to see the new swale work in the next big rain!
©2013 Permaculture Research Institute Sunshine Coast – Permaculture swale addition for increased water management at Maungaraeeda.