Jennifer Wadsworth wrote:Hi Levente:
Interesting question (and I love venetian wells - beautiful).
Caveat - I have no practical experience with venetian wells. That being said - I would love to know your location. If you get down to -25 C, you would probably experience heaving due to frost in the soils and the clay lining of the well which would crack - that would be my main concern.
There may be other approaches that would work to give you multiple yields from a single element. I'm just "spit-balling" an idea here, so here it goes.....
What if you constructed a large ferro cement above ground cistern - because of the way they are made, I believe they can withstand heaving - or they may require a cement pad base. They are very robust and with enough volume, probably wouldn't freeze, especially if you insulated it well. You could insulate it either with something like straw bales built around it - or it could be part of a sun-facing glasshouse attached to a home or other structure. The heat gain created by the glass house would probably be enough to keep the water liquid.
Another thought is adding a RMH to the construction of the ferro cement cistern. With a little stick fuel, you could keep the cistern warm enough not to freeze (it seems). The cistern would also then have it's own microclimate depending on where it was placed that would be essentially warmer in the winter and cooler in the summer - perhaps a niche for starting early seedlings or extending a harvest into the cold season?
In my extremely limited understanding of venetian wells - the sand acts as a fine filter. Gravel wouldn't perform that same purpose, necessarily. In fact, "decomposed gravel" is still decomposing and will make your rainwater harder. What is your roof made of? That will dictate how "potable" your rainwater is and what steps you need to take. There are "first flush" systems designed to divert the initial flush of rain that contains the most debris away from the cistern.
Ferro cement cisterns can be very artistic and beautiful - you could even build them into a structure such as a patio or glass house.
OK - those are just my initial thoughts.
Su Ba wrote:I don't have answers for you, but I have a few more issues you may wish to consider.
I am assuming that you plan to use this water for household use rather than garden use. Based upon this......
1- have you calculated how much water your household uses daily?
2- do you plan use the water for ALL household use or do you plan to use hard water for some functions and rainwater for others?
3- does your area receive year around rainfall or only in a certain season?
4- will you have a back up water source?
4x4x6 meters isn't very large considering much of the volume will be taken up by sand.
As a benchmark.....I live in an area that gets on average 60 inches of rain per year. Thus we have access to enough natural rainfall. Our original catchment tank was a 10x 6 foot cylinder. It proved to be too small. We added a 16x6 foot cylindrical tank, which now sufficesfor a family of two.