Director,
T.E.(Terry)
Manning,
Schoener 50,
1771 ED
Wieringerwerf,
The
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:
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.