Water conservation was an important part of our overall concept for the EcoHouse Risan. The public water supply suffers shortages, especially in summer at the height of the tourist season. We built a 15m3 tank for rainwater collected from the roof, and also have other 200l plastic rainwater collection tanks sited around the garden.
A severe storm can give 30 to 40cm of water over a 24-hour period, and 10cm to 20cm is normal for an average storm. Risan’s annual precipitation from 1961 to 1984 was 3.1metres, most of which seems to fall at once!
While normal domestic consumption is not large, with only two of us living in the house, the garden needs a substantial amount of watering in summer. The garden areas are not contiguous, being around the perimeter of the house, and there is a 6m slope from back to front (south), requiring terracing in places.
The construction of the garden is a work-in-progress, with building work outside the house not yet complete (as at this writing, formation of terraces, a boundary wall and other minor items have still to be completed). Watering is also a vital aspect in preventing the spread of Pierce’s disease which water stress aggravates (https://en.wikipedia.org/wiki/Xylella_fastidiosa). Our 30-year-old vine has been partially infected this year for the first time, as have vines of others in Risan.
We are gradually reducing the overall water requirement by increasing the amount of drought-resistant plants, especially succulents (mainly sedum album red ice and aptenia cordifolia) for ground cover: they are compatible with the native climate and soil requiring little, if any, irrigation and attracting insects and bees. As we have planted olive and citrus trees (mandarin, lemon, grapefruit), the need for watering cannot be eliminated.
Over time we will install a piped drip irrigation system, allowing more precise and controlled water flow to plants. The basic structure for this is being put into place as the sections of the garden are completed. Our present average daily usage is about twice the UK average of 150l per person, but about 2/3rds of that of Italy (375l per person). The difference between summer and winter is dramatic, with summer usage being about twice that used in the winter. So there is plenty of room for improvement!
Buildings currently use 25% of the world’s water. But it doesn’t have to be this way. #BetterBuildGreen #WGBW16
Founder Member and Past President, Montenegro Green Building Council
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© Text James Collins 2016; Photographs James Collins & Anke Harris-Collins 2013-2016