How To Measure Water Garden Pond Depths and Volumes
Pond depth is one of those factors in pond building much talked about and misunderstood especially by those people who "mix" with dedicated koi keepers.
So often you must ask yourself do I want a koi pond in which I want to raise monster sized or prize winning koi or do I want a garden fish pond containing koi around which I can sit with the family and enjoy the scene.
If you belong to the dedicated koi keeper class then yes depth of your pond must not be less than 4 ft and preferably 6 feet. This is quite simply to provide space to swim and exercise a mechanism which in part determines the koi's shape.
For most garden ponds 3 feet is deep enough and even less suits many situations. In cold climates shallow ponds freeze and in hot climates they get very warm. In shallow ponds you see MUCH more of your fish and their behaviour.
Most aquatic plants prefer shallow ponds.
Deep ponds cost much more than shallow ponds ... is this reason for many deep pond recommendations?
Finally the choice comes down to personal preference, space and money available component.
If you need to calculate the pond's volume .... the volume of any pond is the surface area multiplied by its average depth. The more accurately you know both these numbers the more accurate your calculation will be.
If you have a pond and the depth is not constant you can make a very good estimate by taking a stick and mark it in intervals of say 3 inches with an indelible ink pen. At 10 different places in the pond insert the stick and record
the depths (10 numbers).
Add the numbers together and divide by 10. Use this answer as the average depth of the pond.
If your pond is of equal depth and the same cross section then you can accurately measure the pond volume using your pond pump. Do the following ....
Record the depth of the pond accurately before doing anything else.
Using the pond pump and a pipe time how long it takes to fill say a 5 gallons container to the 5 gallons mark (not much more not much less).
Now pump water out of the pond for say 5 minutes
Record the depth after pumping out water
The pond's volume is then calculated as follows:
S = depth of pond in inches or any unit before pumping starts
D = inches or any unit of water pumped out of pond when pumping
i.e. difference between start depth and final depth.
T1 = time to fill the container
T2 = time pump was run to pump out water
V = volume of container
Volume of pond = (S x V x T2) DIVIDED BY (D x T1)
Example:
S = 30 inches
D = 3 inches
T1 = 1 minute
T2 = 10 minutes
V = 3 gallons
Pond volume = (30 x 3 x 10) divided by (3 x 1)
= (900) divided by (3)
= 300 gallons
If container was in gallons then final pond volume is in gallons. If container was in litres then final pond volume is in litres
It does not matter whether you measure depth in inches or any other units.
Use the pump to pump out water in the same position used to fill the container.