Wednesday, 20 August 2014

Rain water harvesting


Our new allotment is completely off-grid, there are no amenities provided on site. For people who dream of being self-sufficient in the future, and took on the allotment to hone our self-sufficiency skills, this is really great news.

One of the key issues we will face is ensuring that we have water. It's difficult to know in advance how much water we will need since the amount will vary depending on the number of raised beds, type of crops and the conditions each summer.


Exeter receives about 1,000 mm of rainfall each year, anywhere between 30 and 130 mm per month.

Annual Rainfall / Precipication Exeter at Airport (EXT): 972 mm

If we collect 1,000 mm (1m) of rain per year from a area that is 1metre by 1 metre then we will have collected one cubic metre of water (1,000 litres)

So, initially that is exactly what we intend to do.

Intermediate bulk containers

Conveniently, Intermediate bulk container (IBC) are designed to hold 1,000 litres.  An IBC is a "reusable industrial containers designed for the transport and storage of bulk liquid". A suitable food-grade IBC may have been used to transport fruit juice for packing and sale in the destination country.


Even though we're only intending to store water on the allotment for garden use (and not for a home grey water system), we'll still be following BS8515:2009.  In practice this will mean collecting water from a greater area to ensure that we regularly flush out the tank and ensuring that the tank is insulated so that the temperature does not rise too high since this would increase the risk of bacteria growth.

  • It may be worth reading the FAO's Introduction to irrigation
  • More to understand on Annual Rainwater Yield (ARY), Annual Rainwater Demand (ARD) and risks like Legionnaires Disease

Wednesday, 13 August 2014

Unethical by default

We know that there are problems in the world, but what if we are driving those problems more than we realise by perpetuating the status quo and failing to make necessary changes?

In the information age it's much easier to be well informed and to discover that our trust in some institutions is being grossly abused. rates HSBC's honesty, ethics etc at 18/100 and Barclays' at a staggering 4/100.

"HSBC holds the record for the largest ever fine levied against a single bank and engages in practices including knowingly laundering money for drug cartels and terrorist groups. HSBC is also one of the world’s biggest investors in illegal deforestation and tar sands extraction."

"Barclays' portfolio shows a complete disregard for the environment, human rights and arms proliferation, giving the bank the lowest possible mark for ethics."

In sharp contrast there are amazing institutions out there that are worthy of our trust and support, e.g. Ecology Building Society (rated 100/100), who only give mortgages where environmental improvements are being made.  Instead of growing irresponsibly they currently have to have a waiting list for people depositing savings (imagine one of the main banks refusing your money because they currently did not have enough projects to make use of it ethically).

We're now subscribed to Ethical Consumer Magazine - a publication that has been running for over 20 years that offers a similar service to Which Magazine, but rates products and services on their ethical and environmental qualities.

We've been very happy customers of Good Energy for several years, so we're trying to make other positive changes including moving our mortgage.

Zero food miles

Being vegan, our meals are generally composed of vegetables, grains and either nuts/seeds or pulses. Since we're trying to cut down on grains we're eating even more vegetables and fruit than we used to. As a result, we buy a lot of veg, some of which we buy organic from Abel & Cole and the rest of which we buy at the supermarket. We used to get locally grown veg delivered, but the quality was very poor and we got sick of throwing half of it away.

We've always wanted to grow our own food, but have struggled with vegetables due to a lack of space in the garden. Not that our garden is small, but it's full of perennials and I've always been loathe to give up my flowers to make space for veg. We've been on the allotment waiting list since Ian moved to Exeter and last Friday we got one. It's on Hospital Lane - just across the main road from our house and only a three minute walk away.

It's the perfect time of year to get an allotment, especially one that needs a lot of clearing as ours does. Currently it's full of grass and brambles (we cleared most of the ragwort, teasels, nettles and dock last weekend) and the ground is extremely uneven, but the soil is beautiful. At home we have heavy clay soil and that is indeed the underlying soil at the allotment (we can tell because Hospital Lane is much lower down than the allotments and the 3 m banks on each side of the lane are clay), but there's a lovely thick layer of crumbly brown soil on top. I'm not sure if it's simply from repeated use of the allotment or from decaying leaves from the nearby trees, but whatever the reason we're not complaining. It's so much easier to get a spade in than our garden it's going to make it much easier to clear than we had originally anticipated.

We've seen lots of wildlife at the allotments already. It makes us feel rather guilty for clearing ours, but we'll have to come up with a plan to provide shelter for things. At least the edges of all the allotments provide a refuge for wildlife and there are quite a few long grassy areas about too. So far we've seen two species of dragonfly, several species of butterfly, grasshoppers, a frog, several slow worms and on Monday Ian unearthed a huge toad. I couldn't resist picking him up.

According to our neighbour the foxes that we see on Hospital Lane also come up to the allotments (and keep them free of rabbits). 

We're really looking forward to growing lots of fruit, herbs and especially vegetables on our plot. It'll be great experience for us (we've always dreamed of growing our own food) and good for the environment too.