Abstract:
A new technology (Capiphon Drainage Belt, or COB) is applicable to drainage and irrigation
tasks. When compared with existing drainage technologies such as slotted pipe, the technology is
expected to provide:
• simpler installation
• less clogging
• lower susceptibility to physical damage
• greater control of the water table, rather than simple overflow or excess water removal.
The COB is a novel design that consists of multiple keyhole-section channels in a thin plastic
belt. The channels lake up water by capillary action, and are not prone to clogging. Once water is
flowing in the rubes, it continues to flow by siphon action even if the belt is not laid on a uniform slope.
This paper is the first of a series that will report on tests into the effectiveness and behaviour of
the new technology (COB). The simple field drainage trial reported in this paper will consist of a series
of plots with conventional (ag pipe) and COB drainage systems.
The pINS will be slowly wet and then irrigated until steady stale flow is achieved. Irrigation or
rain water supply and outlfows from the various plots will be recorded, Soil moisture conditions will be
monitored by surface measurements and subsurface profiling using dielectric and resistivity methods.
Water samples will be taken for basic analysis of chemical and particulate parameters. Trial plot testing
and completion is underway now (August 2005) and results will be finalised in November 2005. The
plots will be turfed with a standard grass with known properties. allowing an estimate of
evapotranspiration.
It is hoped to achieve a steady state or pseudo steady state condition, allowing water balance
modelling of the systems, and consequent indications off1ow regimes and response behaviour.
Current results are for installation and costing comparisons, and preliminary static moisture
contents and resistivity profiles. The moisture content results show that the methodology will allow
good definition of the profile and drainage systems.
The COB is more expensive than tradltional drainage materials, which was reflected in the
costing for the trail plots. Costing estimates for more typical installations indicate that COB may not be
more expensive than traditional drainage installations, due 10 the much lower installation costs, When
the behaviour of COB is better understood, it is anticipated that revised layout and installation methods
may further reduce these installation costs.It is also expected that COB would become cheaper as
production and supplies increase.
