Monday, December 20, 2010

How to plan for a tsunami

I chose to title this post, "how to plan for a tsunami", but please understand I'm using artistic licence here. This is merely a metaphor for how you plan for an outright calamity. I use the term tsunami, as a representative of big water events. They don't have to be sea related - just water and elements of the earth in general.

Anyone living in the South-East Queensland region of Australia, would know that on Thursday 16 December, there was an enormous thunderstorm event. A huge amount of lightning strikes were recorded, and roads were flooded - or at least in our parts they were. Especially at our house. We had a mini water event which caused a lot of damage to our front retaining wall.

This was not only the result of the huge rain event, dumping large volumes of water in our area, it was also the result of the driveway across the street from us overflowing the council spoon drains. I will discuss the council drains a little later, but first I want to say my intention is not to lay blame at anyone. This is nature and it's what is meant to happen. A lot of people will blame the greenhouse effect. I'm not going to argue - I'm not even going to agree, but I will say nature has been with mankind since we were around. It should come as no surprise when major elemental events take place.

I was going to give a detailed explanation of what happened here on Thursday 16 December 2010, but that moment has now passed. I want to focus on how to plan for a tsunami instead. Not as to prevent it from happening again, but to prepare ones self for the eventuality. Many will suggest having an emergency kit (I am not advising against this) but from what I experienced in our region, the battle was just getting out. I will explain only a little, but more so with pictures. There was water flooding the front of the house.


Water entering property from the street above


Water rapids flowing down the ramp


The strip in front of the house was flooded

There was water flooding one side of the house, and I have no picture for the torrent of water that was cutting us off from the other hill of our property, out back.


The clothesline and Middle Ridge chicken coop being inundated
~ all chickens alive and counted for ~

There was only one side of the house to escape and once I got up the driveway in my car and travelled the streets where I lived, there were flooded roads everywhere - houses very close to flooding and dams threatening to break across the very streets I was travelling on. I make no exaggeration. It was only that the rain stopped, that the approaching tsunami eased.

One thing which occurred to me in the days afterwards, was that I was probably safer in my house than I was on the streets - and what if I travelled them and found the roads cut off elsewhere? Rising flood waters? Where to escape to then? How do you escape an elemental force which is so much bigger than you?

Well, I want to start with a very well known story. It's an old one. It's about a man called Noah. Perhaps you're not into bible stories, but stay with me here. Noah was a guy who built an ark. We know that much. He also built his ark to accommodate a lot of animals - so it was a stupidly big boat for anyone watching from the sidelines. Let's not forget the fact he was also building such an enormous vessel on dry land, without semi trailers to move it. How was he going to get to the water?

What can I say, Noah planned for a tsunami and he lived. He didn't go through the process however, without being mocked for his insight - ridiculed by modern wisdom that water just didn't come to boats. It was supposed to the be other way around.

Do I have plans to build an ark now? Well, not in the same fashion, but I've got to tell you something because we didn't listen to a lot of advice given to us, when we built our front retaining wall. I think that's why it survived it's battering at all. We were told drainage pipes weren't really necessary, considering we never get a lot of water in Australia. We were told not to fuss on the drainage layer (or the footings) the first course of bricks would sit on - as it never rains either. I hurt my back "fussing" over the depth of our footings, and I even didn't mind when they went slightly deeper in places.

Basically we were given a lot of advice on the way to building our retaining wall, which was aimed at "best case" eventualities. I'm glad we chose to over engineer and fuss. We wanted to plan for the tsunami on dry land. That's not to say our wall escaped completely unharmed though. The force of the water coming down from the street above, had to go somewhere. It came down our ramp like a rapid, and ripped out the blue-metal back-fill at the end of the ramp.


Blue metal back-fill, dislodged & dumped

The forced of the water flicked it out like grains of sand and dumped it at the bottom. Needless to say we have some cleaning up to do, but we have learned the importance of over engineering. We also have new plans to help secure our wall better. Not just our wall though - our entire property. And with an ample measure of persistence, we may just convince a few neighbours to join in fortifying their property the same way.

First I need to show you in a photo taken the day after, where the influx of water originated from.


Neighbours driveway (left) our property (right)

It came from this driveway (as seen by the silt) and spanned across the road, into our front yard. Many of you may assume we have an issue to take up with council, and this neighbour, and we will perhaps - but in our own way. There are many areas the council has designed poorly, but if we were to tell them straight out - without a discussion- to rectify it, they would simply implement more of the faulty measures that cause these problems in the first place. What's more, they would also make the rate-payer, pay for it.

They cannot help it, they are bound by modern convention and what's deemed best practice.

I'm interested in a more radical solution however. People need to understand they have the power to fortify their properties. They merely have to approach council for permission to plant out their verges. Everyone has grass growing on their verge here, which is really quite dangerous considering some people have to mow on a slope. Dave gets out with the brush cutter - other guys with properties above us, sometimes burn theirs. While I can understand their desire to protect themselves from not having to mow dangerous slopes, what it does is merely cause soil erosion for the properties down hill. The exposed soil is swept off their property, into council spoon drains, sending water (and silt) to escape downhill, wherever it can.

I want to show people that plants actually work. First I have to show you the damage the water caused to our wall. These plantings really finished towards the end of winter - so only a few months growth.


Monstera deliciosa
or Split Leaf Philodendron

Look at this Philodendron, with a pumpkin vine which sprouted from the compost we added to the initial planting hole. Look how the water escaped around the plant, and exposed only those patches of ground around it with nothing growing. Even so, look at the monseta plants roots exposed.


Roots beginning to search for soil to cling to

This is a baby plant, it will probably grow to eight to ten times this size. Which is why we haven't planted a lot around it. We wanted it to have room to grow. But we certainly selected this plant to hold the corner of this wall together. In a few more years, these roots will have weaved an intricate web to bind the soil. Just what you want on a slope! But the proof is already there. Plants help to disperse water (reduce the energy with which its flowing) so it has a much harder time finding its way downhill.

In fact the whole of this wall which got battered with water, didn't loose a single plant. There was only two plants that had some of the debris taken out of their hole, but like I said, there hasn't been much opportunity for these particular plants to grow. They're still in their first year establishing.


Care required

If anything like this happens to your plants, make sure to fill the hole again with good compost and re-mulch as we did. The sun would've cooked these tender roots, as it probably hasn't formed a deep tap root yet. This is a weeping Lilly Pilly, and we hope it does well on our wall in years to come.



The real damage happened to this side of the wall, which was directly underneath where the influx of water came down from the street. It has been denuded of it's mulch.



I love how cleanly the debris has been swept aside. Nature is methodical in her destructive forces, and we ought to observe and duplicate where the least damages are experienced.



Here is a matter of water just merely escaping. It went underneath our little log retaining wall, and carved an erosion gully straight down. I'm not going to lie to you. I cried when I watched our wall being pummelled with all that water. I was in shock at how much water was suddenly flooding the front of the house, and I was saying goodbye to two years labour in one thunderstorm.

Yet to look at it in perspective, it was two years spent building the wall. That part held up. The plants were only babies, and is really the sinew that will hold what's above the wall, in place. Even so, we always knew the street verge (that part of the street council owns, yet charges the property owner with responsibility to maintain) has been our most vulnerable point. If we can plant that full of lomandra grass, which never needs cutting - plus feeds birds with the seeds and bees with the flowers' nectar, we'll have halved our workload mowing and made the verge more like a bushland habitable by all. Not to mention it will slow and disperse the water.

I cannot stress enough to home owners, concrete solutions should be the bones, but not the layer that covers the soil. Plants are made for the soil. They are its natural ally. We could get council to put in guttering, but I have to say, I've seen for myself how it only speeds up the velocity of water travelling down hill. When you live on slopes, you don't want fast water.

This problem will not be solved by merely giving council another wad of paper to stamp. This is about developing dialogue. If we do not take responsibility for that relationship, we just become part of the concrete problem - rigid and just plain toxic to the environment. This problem originated by council planning and developers with no empathy for the unique erosion problems this region encounters. The solution is not to be the same or to blame - adaptation instead.

So strive to be informed, be observational and then be pro-active.

The problem is, we've accepted that things come and go via mechanical means. Someone else deals with the business we pay them to deal with. Yet we are the ones closest to the problem and those most inconvenienced when things go wrong.

At this point however, I don't advise people run around planting at their own discretion to deal with water run off. Observation is required first, plus there is a legal requirement not to divert water onto neighbouring properties - in case it causes damage.

Our first port of call will be speaking with the Environmental Officer of our local council. When we were building, we already did this. The guy we spoke to was very intuitive and read many signs in the land we were just learning about. It was disappointing to discover later he was no longer Environmental Officer. We don't even know if the position still applies - maybe they've given it another name, we hope not. We hope when we contact them again, we will be met with enthusiasm towards mutual solutions. It's in all our interests.

Because if home owners lose their homes, council lose their rate payers and its a big expensive exercise for everyone to repair the damage. But out of all these endeavours towards change, do you want to know who really stands to benefit though?


Our kids...

This is a picture taken of our daughter, the day after the storm. After we walked around the property, counted the damage and made sure she still had tad-poles surviving in her pond, there was time for running in the wet grass. Kids are so resilent to these things and so innocent. They don't have to bear the responsibility of the decisions we make for their future today. Yet they have to live with the solutions we come up with.

Have you thought about plants as a solution on your property? Have you needed to? Will you work with your local council to find better soltuions to old problems?

8 comments:

  1. Wow! Just wow!
    I like that this event has proved to be a catalyst for positive community change. I wish you luck.

    I know the feeling you went through while driving around. We had a horrific amount of rain last summer at the farm. We are high up and don't have flooding issues at all but the lower lying areas flooded heavily. One entire town is now relocating to higher ground as the result of the changes in weather patterns but the real problems are not caused by weather so much as by all the ill thought out levies and dams.

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  2. I'm in full agreeance with you, that the problem became amplified by all the ill thought out levies and dams (I will add spoon drains here too).

    The interesting part though, is we are high up too. The problem was high volume, high velocity water trying to escape down hill.

    Now that we're living with all these prior decisions, it's up to our neighbourhood to slow the water flow from the highest point downwards.

    Softscaping improvements, reduces the velocity of water (holding it longer) so the existing structures have more time to drain.

    My only hope is that council is happy to allow it. Some councils allow people to plant out their verges, others don't. We'll have to see. :)

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  3. Oh Chris, How glad I am to hear you're all ok. What an incredible amount of rain we received!
    (It was a suprise to see you saturday morning!)
    I believe we are excepting more rain! Oh my it is wonderful, but so dangerous.
    I hope your clean up goes quickly and easily.
    And I must say you have a beautiful daughter! - Emily

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  4. Yes, the local paper surprised us the day after too. We guessed they must have listened to the police line that night, as my mum made a call to the SES on our behalf.

    I'm hopeful the rain predicted over Christmas, is at least a bit more moderate, LOL. This was an extraordinary amount of rain that fell on us - more so than in 2007.

    I'm loving the sun while it's out though. :)

    That was my favourite picture of the day (of our daughter) as it said amongst all that went wrong, we can still smile, play and be hopeful in the future. Thanks for your comments.

    I hope you, hubby and the boys have a safe and merry Christmas.

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  5. I didn't realize that you were on high ground in actuality!
    Its hard for me to judge based on photos alone but what kind of soil do I see there? Is it sandy or clay? And is this same soil most common in your entire neighborhood?

    We have excellent soil on most of our property and we have lots of native grasses. Being high up isn't the only saving grace for us. Its the land itself. We have neighbors close by who are higher up but have more clay and they have more problems than we do but these types of problems are not affecting the overall area during the heavy rains.

    We deal with this kind of weather on a regular basis in the Midwest and we generally only see the types of problems that you have when rivers rise. But again, rivers will rise. Why do they rise so much? Poor planning.
    However, I grew up in California which is in a state of emergency now with all the rain they are getting. I think that the problems there are more akin to what you are writing about than where we are now.
    Anyhow, glad that you are safe. I hope the Christmas rains are minimal enough to not cause problems.

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  6. Good deductions there - we are on clay. That's probably why the water keeps skiing off everything to get to the bottom of the hill.

    What you describe about the soil in your area, is what we're trying to achieve here. We need to improve the organic matter, but that takes time.

    The rain has hit us again and they're predicting a deluge again this afternoon. My hope is that it just misses us by a fraction, LOL. Looks like our family Christmas get together is cancelled though. We all made an agreement if it was too wet on the roads, no-one was to travel.

    Better safe than sorry. :)

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  7. One solution our Amish friends have suggested for clay soil is gypsum. I haven't looked into it myself so can't recommend it, don't know how fast acting it might be, etc. They use extensively and they are organic certified. I know they tested their clay first though.

    I prefer to take the slow route myself and the clay is in our subsoil which actually is a gift to us. We don't need to water very often.
    I am sure you will have a wonderful, peaceful holiday but I hope you all stay safe.

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  8. One solution our Amish friends have suggested for clay soil is gypsum. I haven't looked into it myself so can't recommend it, don't know how fast acting it might be, etc. They use extensively and they are organic certified. I know they tested their clay first though.

    I prefer to take the slow route myself and the clay is in our subsoil which actually is a gift to us. We don't need to water very often.
    I am sure you will have a wonderful, peaceful holiday but I hope you all stay safe.

    ReplyDelete

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