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Retention pond module

This calculator forms part of the Wetland Web Calculators series.

The retention pond is a dam or tank used to hold water before re-use (or disposal). Some nutrients and sediments will be removed simply by containing the water for a period of time. This module can also provide a storage for rain that falls on the wetland system. A retention period of at least two days should be used.

Do you wish to include extra capacity to hold rain falling into the wetland system?	Yes No
What will be the normal volume of waste water EACH time the crop is irrigated? (i.e. how much run-off is there?)	litres
How long do you want the water to stay in this module?	days
What depth of trap will you use?	1 metre 1.5 metres 2 metres 2.5 metres 3 metres Other metres
What is the surface area of the grassed soak area module? (Enter '0' if this module is not being used.)	sq metres
What is the surface area of the artificial wetland module? (Enter '0' if this module is not being used.)	sq metres
What is the expected daily amount of rainfall for your farm? (Use an average daily rainfall figure, or you could use a maximum expected figure.)	mm

Do you wish to include extra capacity to hold rain falling into the wetland system?

Yes No

What will be the normal volume of waste water EACH time the crop is irrigated? (i.e. how much run-off is there?)

litres

How long do you want the water to stay in this module?

days

What depth of trap will you use?

1 metre
1.5 metres
2 metres
2.5 metres
3 metres
Other metres

What is the surface area of the grassed soak area module?

(Enter '0' if this module is not being used.)

sq metres

What is the surface area of the artificial wetland module?

(Enter '0' if this module is not being used.)

sq metres

What is the expected daily amount of rainfall for your farm?

(Use an average daily rainfall figure, or you could use a maximum expected figure.)

Results

The following suggested dimensions are based on:
a daily volume of --- litres
length of stay --- days
an initial depth of --- metres

Diagram of retention pond module

Diagram of 'retention pond' module