Another one of our August jobs was installing some rainwater tanks. The task was to put something in that was better than our existing “rainwater harvesting” jug, but was cheaper than the full-on rainwater harvesting systems I’ve looked at before.

The answer was 1500-litre recycled tanks from eBay – they are used once for shipping Orange juice, then they are superfluous. We got three of them for only £80 each – great value in comparison to new tanks, and they came in an as-new condition, needing just a rinse out. We had a lot of fun getting them into position, but luckilyI had some help:

Once I’d got them in place there was the small issue of how to get the water out!

Not being a plumber I was a little nervous, but the solution is surprisingly simple. Drill the right size hole, and then a garden tap – bought from your local DIY place – will screw straight in, cutting its own thread as it goes. The only hitch? Don’t buy taps with one-way valves in – they work fine at mains pressure but the lower pressure from the water tanks was not enough to open the valves. You’ll know if you have these taps – firstly, no water will come out, and secondly they have these little white valves in the ends. Either swap them, or you can lever the little valves out!

With that little wrinkle ironed out, the tanks were all ready – here is one of them hiding behind the shed:

handpumpAnother nice resilient piece of equipment. Assuming you’ve got some local water storage – hopefully big rainwater tanks – you need to be able to get to the water in case of long power shortages, where mains water is likely to be unavailable and power cannot be spared for electric water pumps.

Here’s what you need, a nice traditional Cast-iron hand pump. It’s only £35 and should last a lifetime. If you’re not planning on getting little kids to do all the pumping for you there is a matching stand available for another £35 which brings it up to a reasonable height.

Another one to add to the shopping list!

Steadily firming up the shopping list for our new house – here’s the latest list, with links. 

Kitchen

Dining Room

  • Expandable table

Playroom

  • Instant-heat to stand in front of (Gas?)

Lounge

  • Wood-fired stove
  • Central Pendant light in diffusing shade – 12v CFL?
  • Two Standard/Reading Lamps – 12v CFL?

Garden

  • Kitchen Scraps Compost: Black Soldier Fly Composter / Worm Farm 
  • Firewood store, and at least 12m³ of wood
  • Greenhouse with Aquaponics system

Heating & Hot Water

Power & Light

Water

grafcarat6500lAs promised in my previous post about drinking water, here are my thoughts on our rainwater storage.  In our current home town of Brisbane, Australia, the dams that supply our drinking water recently bottomed out at around 14% capacity. The severe water restrictions that we’ve had for years have meant that even in our inner-city suburb about half the houses have rainwater tanks, as without them you are effectively not allowed to water your garden. These aren’t your British-style 200 litre water-butt either. Hardly any would be less than 3000 litres, most would be 5000 litres, and quite a few have 10,000 litres. We’ve currently got two 3000 litre tanks, plumbed into to an underground weeper hose that runs through all the garden beds, controlled by a programmable timer that runs the two watering circuits on alternate days. This has ensured that we have kept our lush tropical garden alive through a seven year drought.

What it doesn’t do is supply any water to the inside of the house. For a while we did use it for our washing machine (a separate tap that we connected the cold water hose to) but as this required a manual changeover it only happened rarely.

To peak-oil-proof our water supply I want our UK system to be fully plumbed in to the house and able to supply our basic, emergency  requirements, and ideally all our requirements. I’m going to try to do this relatively scientifically – based on the Tank Size Calculator from RainWater Harvesting. Manchester provides a very different scenario to our Brisbane rainfall – there’s 400mm less a year for a start, and it is more evenly spread thoughout the year, minimising the need for a huge tank to cope with peaks and troughs.

With our roof area (about 100m2) and Manchester’s annual rainfall (806mm) we can expect to collect around 64,500 litres/year (at 80% efficiency). That sounds like a huge amount, but when you consider that our current water consumption is around 250 litres a day, we currently use 91,250 litres/year! So to be self sufficient in water with our current roof size we’ll need to reduce our in-home water consumption by around 30% – that looks like the subject of another post!

So what size tank do we need to make sure that we collect as much water as we can, without wasting any? I concocted my own monthly water use chart, based on meeting a target of 170 litres/day (then found out that there’s a very good one in the RanWater Harvesting spreadsheet!).  From looking at this (below) I’ll have a shortfall of 3000 litres in the first year – so in this table I’ve pre-filled the tanks with 3000 litres to ensure that they don’t drop below zero. In reality this “top up” would happen in stages during the year depending on our actual daily consumption to give us the chance to be extra-economical as the levels drop. 

  Rainfall /mm Water Collected /litres Available Litres
/day
Water Used
(170 l/day)
Net
Water
Storage at Start   & End of      Month
Jan 71.5    5,720 184.5     5,270 450  3,000     3,450
Feb 51.8    4,144 148.0     4,760 -616  3,450     2,834
Mar 64    5,120 165.2     5,270 -150  2,834     2,684
Apr 49.1    3,928 130.9     5,100 -1172  2,684     1,512
May 53.8    4,304 138.8     5,270 -966  1,512       546
Jun 66.8    5,344 178.1     5,100 244     546       790
Jul 59.5    4,760 153.5     5,270 -510     790       280
Aug 70.9    5,672 183.0     5,270 402     280       682
Sep 69.9    5,592 147.2     5,100 492     682     1,174
Oct 86    6,880 221.9     5,270    1,610  1,174     2,784
Nov 81.9    6,552 211.4     5,100    1,452  2,784     4,236
Dec 81.4    6,512 210.1     5,270    1,242  4,236     5,478
Year 806.6  64,528 176.8   62,050   2,478    

In this our water storage peaks at around 5,500 litres, so unless we manage to keep at or below our tight 170l/day target for several years there is limited benefit to installing a tank any larger than 6,000 litres

Tank Suppliers

Resources

Whether you’re out building snowmen or huddling around a radiator, now is a good time to reflect on how prepared you are for these type of events. If you can’t get your car out, then consider how much food you have stored. How long can you stay at home without getting hungry? There are a range of things that we can and should be preparing for. luckily the Government has taken a lot of the hard thinking out of it by preparing the National Risk Register which shows how likely and how severe events can be. They have a great section on the Considerations for Families in a range of emergency situations. Even more interestingly, there are  Community Risk Registers  developed for every area of the UK – use Google to find your closest one. Ours is GM Resilience for Greater Manchester, and I’m hoping that the website isn’t an indication of how prepared Manchester is – half the links don’t work and the latest Community Risk Register is 2006/7!  

Actually I’m wrong – the link says 2006-7 but when you download the register (here) it is from Sept 2008. It has quite a comprehensive list of events, all ranked with their likelihood and severity.  The one that particularly stood out for me looked at fuel shortages, and has a 5% chance of happening within 5 years :

Significant or perceived constraint on the supply of fuel. E.g. industrial action by contract drivers for fuel.

  • Filling stations, depending on their locations, would start to run dry between 24 – 48 hours.
  • Panic buying would exacerbate the situation.
  • Replenishment of sites would take between 3 – 10 days dependant on the location.

They have also rated the chances of  a loss of water for three days (0.5% chance) or for a week (0.5%); loss of power across the whole region for a day (0.5%), or for three days – causing civil unrest! (0.05%)

I think it’s interesting to look at these from a personal preparedness point-of-view, and also to view them with peak-oil-tinted-spectacles. What happens when these things start to become regular, or prolonged occurrences? What happens when they all start to converge and occur at once? If they are planning for Civil Unrest as a result of losing water for three days, what do they think will happen if we all have no fuel, power or water for a week?

The number one item on my domestic resilience list is maintaining access to clean, safe, drinking water.

Coming from Brisbane, where the dams that supply our drinking water recently bottomed out at around 14% capacity, I am keenly aware of the importance of available water.  With increasingly unpredictable weather in the UK, and water treatment works subject to flooding and blackouts this is one area I don’t want to take chances on.

I am already planning significant rainwater storage (I’ll detail this in a separate post), but I need to make sure that water will be safe for us to drink. The best way to do this for moderate amounts seems to be a countertop water filter. The best one I’ve found so far seems to be a British Berkefeld (Berkey) Water Filter. It’s gravity fed, so no power is required, and it can produce up to 80 litres a day – easily enough for our drinking needs. Cost – around 90 quid. Even better – it’s made in the UK, so you’re also supporting local manufacturing when you buy one!