Sunday, September 11, 2011

Rainwater Catchment System

At long last we are in the process of installing something that I have wanted for ages: a serious rainwater collection system. How I regret not researching water conservation better when we were building this house! Retrofitting is so much harder than building to design... Where were my braincells when Best Beloved was urging me to 'really think about what you want and how we can include it, because making changes later will be hard, if not impossible'. 

Leo and I (see his feet sticking out?  He's holding the flange
inside the barrel while I tighten the outside) experiment with
creating a filtration barrel.  The barrel will be contain a layer
of stones and gravel, and will filter debris from the water after
the initial 20 minutes of rain have cleared the roof of dust and
 bird poop. The final version will have the outlet emerging
from the bottom of the barrel rather than the side.

...But that's another story... Mea culpa, he was right.

Water conservation is not high in Best Beloved's agenda. He believes that rain should be allowed to run off the roof, soak into the earth, and recharge the water table 'in its natural cycle'. I agree, but think that that rain should be made to do as many things as possible before being allowed to slink off underground and run to the sea. And that in a country as dry as Cyprus (Paphos regional rainfall is 50 centimetres per year – almost all of it falling between the months of April and November), it should be everyone's responsibility to catch rainwater and use it instead of relying on the dams and the – often antiquated – village cisterns and delivery systems. Add to our arid conditions the fact that tens of thousands of people have moved here over the last few decades with their requirements for swimming pools, lawns, and manicured golf courses, and you will see that the strain placed on our water sources and the conventional management practices, is growing every year.

Hence my mania for water storage and recycling.

Best Beloved, I reasoned, wants a swimming pool in the future. Maybe we can create some kind of rainwater natural pool..? (Impractical, it turns out, thanks to the harshness of our climate and the total lack of experience in the matter in Cyprus. There are a few in Israel, but we were unwilling to gamble on the expense of creating one here and ascending the learning curve on our own.) Maybe at least we can catch the same quantity that we would use in a pool and recycle it back into domestic and garden use? That is a distinct possibility – and more.

Strangely Cyprus, despite hosting seminars for our neighbours the Israelis, Jordanians, and Palestinians to learn about rainwater recycling togther on neutral territory, has no initiatives of its own for catching rainwater – or, novel concept, for collecting and sharing water and knowlege with our Turkish Cypriot bretheren. If the Israelis, Palestinians, and Jordanians can combine their interest and expertise and weave their shared experience into another strand which strengthens the possibility of peace between them, why can't we? But that, too, is another story for another day...

Over the last year or so I have been researching madly: reading books and contacting experts as far-flung as Israel, Australia, India, and Arizona. Following raincatcher guru Brad Lancaster's instructions, I have improved the land's ability to retain water by constructing berms and mulched basins around the fruit trees, the olives, and any other plants, and have been looking at the house and pondering how to use our enormous roof area (132+ square metres on the main structure alone) to maximise water collection.

D-Rain tanks seemed to be one possible solution, with the siting of a massive underground tank at the bottom of the driveway, but a quote from the German company that produces them was prohibitively expensive – and that was before we had even included the local construction costs.

Only the main part of the roof will be guttered.  Collection/
filtration tanks will stand at both ends of the house, sending
 the collected rainwater to the large holding tanks on either

The catchment for the main part of the house – excluding the verandahs and the roofs of the lower rooms – is around 66 tons, using the figure of 50 centimetres of rainfall per year. Siting of tanks and positioning catchment systems took hours of pondering and discussion spread over a couple of weeks, and here, BB's clarity of thought won out over my unreasoned vision. “We'll put the first tanks on the lower terrace of the slope on the kids' side of the house,” he said. “And depending on how well the system works, we'll bring a digger next year, level parts of the other side, and put in some more there.” Meanwhile, we would install guttering on the upper roof (the lower, verandah roof does not have sufficient height to allow for a collection/filter tank underneath with enough slope to run off to the holding tanks. Most of the run-off from the verandahs and lower roofs is already channelled into garden beds and the area where eventually the pool and lower garden will be landscaped, and that which isn't accounted for will be easy to deal with at a later date.

The 2.4 x 11m terrace which will hold the first installment of
four 8-ton rainwater holding tanks for use in the garden.

I checked several websites for tank manufacturers. Varelplast in Larnaca makes twenty-ton tanks, but they are too big to put on the side terrace, so we have opted for an in-line connection of four eight-ton capacity polyethylene tanks from VitaPlast in Nicosia. An English company, DrainTech came out from Paphos to give me a quote for heavy duty PVC guttering, but their price was double that of a Cypriot company's aluminium work – which seems to do a fine job directing the water from Phil and Mili's roof – so we're going with Windorama. They are coming to do the work while Sophia and I are in the UK inspecting boarding schools for next year.

Best Beloved and I worked out a gravel filter system for the initial collection tanks, and he has arranged for several local craftsmen to create the structures that will hold them and install them in our absence: frames for the big blue barrels and galvanised archways to carry the downspouts from the guttering over the walkways and into the big tanks.

The blue filtration barrel is not in its final position.  The first
array of tanks will be on the terrace below the fig tree, and the
pool will ultimately be in the flat area in front of the van.

I can't believe that we are finally doing this... Oh, Asproulla of Little Faith, didn't he promise you at the end of last summer that we would do it before this winter? And has he ever broken a promise?

Watch this space for updates! 


  1. These people were a bit more affluent and had installed rooftop rainwater harvesting systems into a sump tank. Both the families said that they had rainwater for drinking and cooking.

  2. “Retrofitting is so much harder than building to design... “ I agree with this one. A rainwater system can’t be assembled easily, and it’s not as simple as it looks, too. There are various components like catchments, coarse mesh, conduits, and so on which need to be constructed as scrupulously as they were designed. How’s it now? I hope you weren’t encountering cracks with the system, or else it might flood the surrounding areas. I hope you were saving a lot on that. :)

    Tabatha Tidd

  3. That all you told us about rain water harvesting storage planning stories of various regions which is quite good according to their regional conditions. And also Retrofitting is so much difficult to design. Yes I totally agree with your opinion.
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