As the roads have turned to soup, the hills have become treacherously soggy as well. Behind a group of fig trees is a valley I’ve been considering for some time how to protect and improve. It’s tricky because there are power lines overhead nearby, plus two steep hills, with the water source for the grazing sheep at the creek on the far side.
In any plans I’ve drawn up for tree planting, my focus had been on the rocky areas up to the left, and on the actual watercourse in the middle of the valley, not the smooth slopes (green in the picture) that seemed okay.
In recent months I’d noticed that the gate to the paddock was now in a marshland, due to the water flowing down the gully from the hills. Any drop of rain has been running off instantly because the water table is so full. The track up the valley was impassable.
I waded around in the bog one day thinking about how I would place giant boulders, hmm, don’t have any conveniently on hand, and how would we move them through this sudden wetland? Maybe rotten hay bales, which Andrew has given me permission to use, but are also difficult to move, particularly in a bog? Or gabion walls made of wire cages with smaller rocks piled inside? That could be the best but still hard work.
In the meantime, the roads were flooded several times, so we stayed in town and didn’t notice that there’d been a landslide.
Andrew pointed it out to us, since we hadn’t seen it on our way home.
We walked down, but didn’t go too close because of the sticky mudholes and pools of water. At first all I saw was the open mouth of the slip on the hill. Didn’t seem so very big.
Then we sloshed a bit closer and I tried to open the gate at the bottom of the hill, one I’d had built only a few years ago to replace the old rotten war-barb fence. It was stuck, the wires pulled tight.
That made me realise that the whole lower slope had moved, not just the piece that had opened up. The soil, grass and all, had been shaken down like a blanket and moved the fence a fair way sideways. The whole shape of the ground had changed into a new lump.
What we didn’t even notice then, although I had some feeling that the upper gully also didn’t look the same as the day I’d considered the gabion walls, was that there was an even bigger slip further up. James the Bobcat Master had to point it out, a huge bulge in the side of the gully.
I went up to look at both slips yesterday, filling my socks with grass seeds but not sinking into any bog holes as I’d feared. The mud has dried quite a bit after just a couple of weeks without rain.
The lower one had a flat area that had obviously been soft mud until recently, as testified by all the deep hoof prints.
The bigger slip was more subtle than the lower one, but it’s much wider and quite massive. I tried to photograph it, but it mostly just looks like tumbled long grass. Each step was a surprise, some quite deep. I calculated maybe 350 tonnes of earth had moved down.
I also had fun trying to work out where the line of the slips on the hill were.
This is now the biggest slip we’ve had, bigger than the one that’s moved the drainage ditch on the road down to Lizard Crossing, (which causes trouble for getting the water off the road) and bigger than the one just by the Lizard Crossing bridge which was the first we saw…seemed big enough at the time.
There are some old slip-scars on the steep slopes of various hills where springs emerge. Most of them were there when I was a child. It apparently takes a year of rain like this to cause new ones. Where there are trees they help hold it, of course. Even the two dead trees further up the valley may have done that job, as their roots take decades to decay.
Anyway, it’s back to the drawing board to consider how to improve this area effectively in the future.