How much water is in my dam?
MOISTURE CONTENT ON DELIVERY
Grain is seldom sold at the standard moisture
content. When the moisture content is greater than
the standard, the weight of the grain is discounted
to make provision for the additional moisture.
The following moisture content standards are used
as condition for the delivery of commodities at
Delivered Agreed standard
For example: Maize is delivered at a
moisture content of 14%.
(100% - delivery %)
(100% - standard %)
= (100% - 14%)
(100% - 12,5%)
By multiplying the weight of the grain
delivered by 0,9828, the weight of the
maize is calculated at a moisture content
of 12,5%, for example the weight of a
load of maize of 32 000 kg delivered at
14% moisture is (32 000 kg x 0,9828)
31 449,6 kg @ 12,5% moisture content.
≤ 14% 12,5% – dry
≤ 14% 12,5% – dry
≤ 13% 12% – dry
≤ 10% 9% – dry
There are a few measurements that you need:
The surface area of a dam is calculated by
multiplying the length by the width.
This will be the case for square or rectangular dams.
Most dams start out as a square or rectangle, but
over time appear to become rounded. If the dam
is not exactly square, round the measurements off.
Make sure to err on the conservative side.
Dams such as Turkey Nest dams (used to store
water on a relatively flat terrain) can be any shape,
and their dimensions may need to be approximated
to calculate the surface area.
Gully dams (used to store water in a gully) can also
be of varying shapes and the formula for calculating
their storage capacity is discussed later.
With the surface area depth calculated, the volume can then be determined:
(Where 0,4 accounts for the batter slope on the sides of the dam)
Turkey Nest dam
Example: 30 metres x 50 metres = 1 500 m
) = Surface Area (m
) x Max depth (m) x 0,4