Since this blog post from last autumn, when we were just beginning construction of our dream home in rammed earth, the project has progressed to the point where (as you can see above) the building is structurally complete. Meanwhile: Zone1 surroundings have come to look like a moonscape!
The Design Challenge for this season and beyond
Overall: Staying true to the vision that motivated this project (and the larger project of Quinta do Vale da Lama) it is to create an oasis of sustainable good-living, in spite of the desertification trend that threatens all around us.
More immediately (this fall/winter): In Zone 1 surrounding our house, it is to create a Water-Wise Mediterranean-style garden: a perennial plantscape that will be a joy to us all the year round, without exceeding our annual rainfall budget.
Now: Is this even possible? I honestly don’t know. Yet, as far as retirement planning goes, I cannot for the life of me conceive of a worthier challenge. So here we go!
Since being turned-on to Rainwater Harvesting for Drylands and Beyond, I have looked to Brad Lancaster’s publications for guidance on these issues, more than any other source. If you are interested in the topic, but don’t have time for his books, then this little video tour of Brad’s Tuscon AZ (SW-USA) homestead is probably the best source of information & inspiration you’re gonna find in 12-odd minutes.
Furthermore: greywater guru Art Ludwig – author of “Creating an Oasis with Greywater” , another seminal book in this field – explains his Laundry to Landscape greywater system in 5min… Which pattern has inspired a fine chunk of plumbing in the EcoLair. More on this topic shortly!
So what are the main water-wise features of this EcoLair?
From source-to-sink, i would prioritize the top-5 features as follows:
- Integral rainwater catchment
Rain-gutters are an integral part of traditional clay roofing where it sits atop the earth walls. With a surface area of roughly 250m2, assuming a rate of 500mm/yr, we might expect to be receiving & channelling some 125 m3/year, to…
- Rainwater storage
Considering this estimated rate of flow, we have decided to implement a cistern with 25m3 capacity, in the form of a drum with both radius and depth of 2m (buried). This will not be holding all the rain that falls in an entire year, obviously, as most rainfall is to be stored garden beds and biota (the cheapest and best place, by far).
- Greywater-conscious household plumbing
Each WC with two circuits of both output (i.e. black vs grey water) AND input (i.e. recycled water in to toilets, and clear water in for the rest). Each source of greywater output (whether sink or shower or tub or machine) has its own output to garden, and overflow to ETAP (a biological sewage system, TBD in another post). The implication of this is: some complicated plumbing! including vacant channels for system expansion (i.e. the 4 holes pictured below, for selective channelling of greywater from laundry).
- Planning & Management of effluent flows
In the aforementioned book, Art Ludwig estimates 3,270 LPW (Litres Per Week) of output for a typical family of 4, which seems to map pretty well to our case. If this proves to be anywhere near true (to be metered and managed ongoingly), then it is quite a rich vein of resource to tap, for purposes of supporting…
- Plantation strategy
- Climax layer of Mediterranean dry-fruits. Olives, carobs and almonds being the extant species, affirmative action is accorded their maintenance
- Perennial understory of shrubs, sub-shrubs and ground cover: all drought-tolerant native and adapted species
- “Sensual Layer” of aromatics and flowering species, selected to ensure year-round florescence
- Deciduous foliage around house, to admit sun when we want it, and filter it out when we don’t… Especially around the common area (SW end of house).
Immediate Focus: The sunset terrace
Given its location (central to common area) and orientation (facing southwest), this is the “hot corner” (literally!) of our home landscape design right now.
Critical need: to provide verdant shade on this terrace where we will most commonly hang around, i expect, during the dog-days and long-evenings of summer.
As you can see in the photo above, this terrace is over-arched by a pergola, supported by four columns of tijolo burro, arranged about the perimeter of a ceramic tile floor, which- per hardscape design below-will itself be surrounded by a permeable paving of calçada.
Trapadeiras: by the 4 pillars, my top 5 climbers are:
- * Wisteria vines: nitrogen-fixing as well as beautiful, my only doubt is regarding the damage they might do to hardscape and foundations
- * Passion Flower vines: equally beautiful, perhaps (hopefully!) less aggressive
- * Cape Honeysuckle: a South African import, but well adapted; have had good success with these elsewhere on the farm
- * Bougainvillea: a local classic, but gosh they drop a lot of litter! (Lovely litter, mind
- * Grape arbor: Q: With so many grape vines on the farm already, why plant more? A: Because they are there!
Depending on the type of climbers to be planted (some of those above are more problematic in this regard than others), these holes for plantation in the calçada must be deep enough that the roots will go down for their water, instead of going sideways. Moreover: we want a deep natural sponge at bottom of the planter, in the form of rotting wood, to retain moisture while building on the 3Ms (i.e. Minerals, Microbes & organicMatter) of good soil.
Ecological appliances and products:
- * Appliances: Low-flow clothes and dish washing machines (key players in our greywater-powered ecosystem) are yet to be procured or even selected; got to do some research in this area.
- * Cleaning Products: We use Ecover -readily available in local stores- but I’m not sure if it’s the best alternative. Other options, anyone?
Given that this likely the last stop for the wife & I, and also the legacy that we will leave our progeny – whose most extreme existential threat is the problem of desertification, alas- my commitment to Water-Wise development from here on out is absolute. I am indebted and deeply grateful to those pioneers in this field mentioned above, and keen to work with anyone else working along similar lines. If you such a one, by all means please get in touch.
The last word:
Here’s a short video from Brad Lancaster, illustrating key concepts…