permaculture

[Marsha Hanzi <hanzibra@svn.com.br>]

As to rainwater catchment:

        Here in the Brazilian drylands the most practical ( economically and 
in
terms of setting up) form of cistern so far has been cement forms which
the farmer prepares on the ground and then joins up- there are literally
thousands  which have been made this way, and have proven to be
satisfactory.  Now these cisterns are being built with  "cabbage-cement"
as they have been substituting the  chickenwire with those red nylon
bags that oranges and cabbages come in (at least here)... which can be
had free-of-charge.
        Recently a local ( in Irece) mason  developed an even easier and more
foolprooof version which I have not seen, but , as it has been explained
to me, is the following:
        He builds up  the cistern first with small adobes, uses these to give
form and  support to the cistern, putting a layer of sand on the outside
of the adobe to hold the cement.  He then weaves wire around the adobe ,
and up and down as one makes a basket ( chickenwire is prohibitive here,
and using just wire makes it much cheaper).  This is covered with the
layer of cement( I believe it is the usual mixture of 2 of sand to  1 of
cement) and left to dry.  When it is firm, the adobes are removed and
another layer of cement is passed on the inside of the cistern.  The
final cost was approximately 150 dollars for 10,000 liters  including
labor , and took one day to build.  This mason has successfully built
3,000- liter cisterns with this method.  This is the first time he built
one of 10,000 liters, which is still under observation.  After 2 months
it is holding well, with no leakage, one of the major problems when the
cisterns are built with separate forms.

Marsha Hanzi
Instituto de Permacultura da Bahia
Brazil