Update on the allotment and home rain water capture and storage project
I’ve made a lot of improvement to the water capture and storage on all three plots with the aim to be self-sufficient until the water is switched on in April and after the water is switched off in October. We’ve also upgraded the rainwater capture and storage at home.
These improvements capture 86% of the rain that falls on EVERY structure on the plot in the year. That means 26m2 of capture area, feeding 2.6 m3 of interconnected storage.
The payback for these investments was 10 years, which makes no sense as an investment, but the value of water over winter is HUGE as that investment is only 2% of the winter harvest value. So while access to tap water would be a lot cheaper for me, it’s not practical due to the risk of frost damage to the site’s water infrastructure. Bottom line, it’s a good investment to save as much rain water as I can.
This video looks at whether it makes sense to add any more storage capacity
As I said we capture 86% of what’s available, I have no more structures to capture from and building a structure just to capture more water makes no sense at all. I could capture an additional 3 m3 of water over winter, which would get me to the end of May. To capture all of this additional water I’d have to add three IBC tanks!
These additional three IBCs would fill over winter, BUT would then be empty until winter came around again, ie they would only be used one.
Unfortunately I don’t have space for three IBC tanks but fortunately tap water is incredibly cheap, the cost of the tap water I will use in a whole year is much less than 1% of the harvest value that depends totally on that water. Were I to add one additional IBC tank the payback would be 13 years, two tanks have a payback of 20 years, three tanks 16 years. Adding one IBC tank would save £6 off the water bill, two would save £11 and three would save £16. It makes so much more sense to pay the extra money. So that’s what I do, by donating to the allotment committee an extra £50/year at the open day.
It’s worth pointing out that I use more water than an average allotment, because I grow mainly leafy greens and crop them intensively, leafy greens are by far the the healthiest and highest value crops and the most difficult to buy organic – but they need a lot of water.
It also makes sense to encourage plants to develop deep and healthy root systems, water the root zone, mulch the bed surface and incorporate a lot of organic material into the soil, I do all of these things. Some plants of course don’t need much water, so this analysis might now apply if you grow onions and brassicas, or if you are on low lying land close to the water table.
Finally for us it’s possible to grow some thirsty plants at home, potatoes in containers for example, so we are doing that because we have a huge amount of rain water available there now. With the two water butts we have at home our tap water costs should be £1. The payback at home is also about 10 years, however it’s worth it to get access to slightly acid rainwater, rather than alkaline tap water.
Adding an additional IBC would save £6 off the water bill and have a payback of 13 years. The IBC tank would displace the existing compost bins and as a result I’d loose £25 of compost a year, which completely offsets the water saving. Adding a second IBC would save an extra £5 of water, but would have a payback of 20 years, a third IBC would save a total of £10 and would have a payback of 16 years!
Bottom line is that more water storage makes no financial sense. It makes much more sense to use tap water to supplement rain water from mid-April – early October and to donate the cost of the tap water to the allotment society which I’ve done every year so far.
Source of rainfall data: https://www.metoffice.gov.uk/public/weather/climate/gctf4tb4d
If you want more videos of me talking about water (only for the really keen viewer!!) check out the playlist https://www.youtube.com/playlist?list=PLFhKoRR-NiCJ64KsGtfFoqN8NRv8x2BaT
If you are new to my allotment videos you might find a bit of context useful. We live in the north west of England, in Lytham St Annes, which I believe is the equivalent of USA Zone 8.
We have three allotments in my family, mine (Steve), my wife’s (Debbie) and my middle daughter’s (Jennie). We also have a small kitchen garden at home. They are all managed in an integrated fashion, so don’t expect to see the usual mix of veg on each plot. I do most of the planning and seed starting. We each have our own plots, but we all help each other out.
Jennie’s plot has been designed as a traditional allotment, but we put a lot of focus on minimising the work we do there. It’s basically a plant and forget it plot, full of garlic, leeks, onions, potatoes, brassicas, squash, beans and fruit trees. It’s heavily mulched to reduce weeds and easy to water.
Debbie’s plot is mostly full of perennials, it’s a garden plot. Again we did a lot of work to keep the weeds down and Debbie’s approach is inspired by the TV programme The Ornamental Kitchen garden.
My plot is all about experimental growing, maxium productivity and year round abundance. As with all of the other plots I did a lot of work to control the weeds, but it’s a high maintenance plot. I’m always planting, harvesting, experimenting and generally having a great time.
Collectively the plots deliver an amazing abundance of fruit and veg all year round. Debbie, Jennie and I are effectively self sufficient in veg all year round and in fruit for much of the year. During winter we have enough surplus to feed a few more of our friends and during the rest of the year we feed up to 22 people.
This video provides an overview:
I do an update of the allotments, roughly one a week, you can find the tours here:
Our approach to allotment life is to: grow as much as we possibly can, to be self-sufficient in veg all year round and in fruit in season, to give away our huge surplus to friends and family, and to have as much fun as possible. For more on self sufficiency check out these videos:
Debbie and I spend about 4 hours a day, 4 days a week on the plots (on average) and we keep nudging that down as we eliminate non-productive work: like grass cutting, weeding and watering as much as practical. We are both newbie gardeners, only starting the allotments in 2016.
I’m a bit obsessive about the nutrient density of the veg that we grow and making the plots easy to work because it’s through this allotment lifestyle and food that I’ve overcome a debilitating auto-immune disease.
I’m always aware though that it might not last so I make sure that I don’t work too hard, eat as much organic fruit and veg I can and design the plots so that I can still work them if I flare up again.