I have lived in SE Queensland for the last 16 years, and I did a PDC about 7 years ago, but unfortunately never followed it through with any action. Work and life got in the way, and the timing never seemed to be right, but what I have learned has never left me, and although I am severely lacking in experience, I have continued to grow my knowledge by reading books, lurking on forums like this, watching videos etc.
Well, it seems like things are coming to a head, and I will finally be able to put what I have learned into practice. We (wife and I) recently bought a property in NW Tasmania. It is about 3.5 acres with a creek running along it's back boundary. The property has a main house and a separate (but semi-attached) cottage. Our short term plan is to convert the cottage into a cafe. Our long term plan is to build up a permaculture market garden that will be the source for much of the food that we create in the cafe, as well as a future teaching site.
We already have some challenges though...
We went for a trip down there a few weeks ago, and the timing could not have been better (or worse). Two days after arriving we were in the grip of a flood. The small trickling creek at the back of our property became a raging river that engulfed our entire property. There is a fair amount of damage to the house and cottage, which we are hoping will be covered by insurance. During the flood event we were able to meet a lot of the neighbours, and most of them said that they had never seen a flood like this. 1 in 50 years is what most people are saying. Regardless, we need to prepare for a similar event in our plans. As we all know, one in fifty years events seem to be happening every second year now.
Here is a shot of the river gushing towards our home (the building in the foreground is not the home, but a barn. The cottage and house are behind that). As you can see, the water wanted to curve around the buildings, but there was too much of it, and the overflow was what did the damage. We are thinking about turning that area, where the yellow arrows are, into a carpark (a legal obligation of council if we are to open a cafe). I'm thinking about raising it up a meter or so to assist the diversion of water away from the house.
Of interest is the shape of our property. the South side has a very narrow part, with sharp banks on either side, which acted as a "funnel" during the flood, focusing and intensifying the flow of water...
That's challenge #1.
Challenge #2 involves the fact that this property is in a high sensitivity karst area, meaning there are caves and underground streams all around the area. What exactly is under our property we don't know. What we do know is that the property is extremely undulating. It's really hard to show this in photos, but after the water started subsiding, we got some shots with water still in the depressions. We are not sure if the depressions are because of the karst system, or because of previous flood events like the one we just experienced. My initial thinking is the latter, as we watched these depressions fill up as the creek rose. I have also included a hillshade basemap overlay, which gives a good idea of exactly how extensive these depressions are. The rest of the land is relatively flat, but I'm still not sure what to do here, and this area is north facing zone 1, so I want to put it to good use.
Does anyone have any experience in karst areas, or any "out of the box" ideas about what to do in these undulating areas?
