Director,
T.E.(Terry)
Manning,
Schoener 50,
1771 ED Wieringerwerf,
The Netherlands.
Tel:
0031-227-604128
Homepage:
http://www.flowman.nl
E-mail: (nameatendofline)@xs4all.nl : bakensverzet
Incorporating
innovative social, financial, economic, local administrative and productive
structures, numerous renewable energy applications, with an important role for
women in poverty alleviation in rural and poor urban environments.
"Money is not
the key that opens the gates of the market but the bolt that bars them"
Gesell, Silvio The
Natural Economic Order
Revised English
edition, Peter Owen, London 1958, page 228
Edition 11: 28
September 2006
This project does not cover all the possibilities
offered by efficient rain-water harvesting. Instead, it assumes small-scale
rainwater harvesting systems for agricultural purposes will be developed as a
natural extension of economic activity in the area.
Rain-water is harvested both for irrigation and
for drinking water. Some form of purification system is needed when it is used
for drinking water as the water may come into contact with dirty surfaces and
may need to be stored for quite long periods. Purification needs systematic
technology application and careful management. The effects can be disastrous if
these things are overlooked. That is why clean water from closed wells and
boreholes has been preferred as a source of drinking water to harvested
rain-water in this project.
The solar powered drinking water systems
foreseen in this model project offer a limited capacity suitable for human
consumption, small animals and small scale drip irrigation applied to high
value cash crops. The project does not include water for irrigation and general
agriculture for which the use of solar energy, taking into account the cost of
PV panels and/or wind generators into account, is still relatively uneconomic.
Rain-water harvesting offers the possibility of
providing a water supply suitable for agriculture. The use of gypsum composite
water tanks and reservoirs made under the (LETS) systems means that users do
not actually need to have any "money" to start and gradually expand
their own rain-water harvesting systems.
The tanks can be gravity fed off roofs and/or
slopes and/or road surfaces. This water would also be used for personal hygiene
such as showers, and for the washing of clothes.
This project is limited to household water
harvesting systems as a supplementary non-potable water supply for personal
uses.
Surfaces such roofs, roads, squares need to be gently
sloped so that water can run along gutters or other channelling material to one
or more water collection points. The channelling materials used should be
locally made gypsum composite materials to avoid financial leakage from the
project area. In any case PVC must not be used. The collection surface(s)
should be kept as clean as possible. Contamination of the surface by animals
and waste products should where possible be avoided. Green or
"living" roofs are ideal for rainwater harvesting. The number of
water collection points will depend on the surface being drained and the
maximum intensity of the rainfall. Purely indicatively one collection point
should serve about 40m2 or 300 square.feet..
The harvested water is intended for general household
use and not for drinking. Should it be required for drinking purposes it must
be boiled. Chlorination and other types of water treatment should be avoided
except where the water in the rainwater tank is the only source of water
available and it is known to be, or there is a reasonable risk that it be,
bacterially infected. Even then treatment should only be carried out by a
specialist.
The harvested water should however be filtered
to keep organic materials, solids and particles in suspension out. This can be
done is two phases:
a) At the collection point, with a fine metal grate together, eventually, with
a suitable sponge-like material at the top of the down-water pipe.
b) Above the water tank, where the water can pass through a gypsum composite or
other container (but not PVC!) filled with (locally available) shingle, sand,
and charcoal.
The size of the filters will depend from case
to case according to the maximum amount of flow reasonably foreseeable.
Their size will depend on the maximum amount of flow
reasonable foreseeable, but will typically have an internal diameter from
3" to 6". Their length will depend on where the water tank is
situated. They should be as short as possible. Where they are exposed to the
sun's rays, the pipes must be resistant to them. Where possible the pipes
should be made from locally available materials and supplied within the local
LETS money systems. Do NOT use PVC material.
Where possible, the water tanks should be sealed and
placed just under the roof, from where they can be gravity fed through pipes to
outlet points in or around the house. Recipients can also be placed on a stand
between roof level and floor level, so that gravity feeding is still possible.
Where neither of these is feasible, ground level recipients can be used. This
usually involves the use of lids, ladles, buckets and similar which may not be
hygienic and the risk of infection and access by animals and insects is
increased. Ground level tanks also occupy extra space.
The water tanks will normally be spherical in shape
and made locally under the LETS systems from gypsum composite materials. Where
they are esthetical in appearance and design, their position is irrelevant.
The first systems will be made in the gypsum composite
factories and installed towards the end
of the second year of project execution. This work will continue during the
following 4-5 years until all of the (10.000) houses in the project area have
been equipped.
List of drawings and
graphs.
Typical list of maps.
List of key
words.
List of abbreviations
used.
Documents
for funding applications.