You would have now decided on the shape and general design for your pond at this point. And that you want to construct a concrete pond instead of a liner pond.
First thing to do is to plan out the outline of your garden on a graph paper, then start to draw the outline of your filters and pond. Once you have that done, you can start putting your plan into action in your garden.
Marking out pond
Mark out the concrete pond with markers and rope/string (if you are marking out a pond with straightlines or a hose if your pond has a curved outline), and use items like stepping stones to roughly show the position of the bottom of the drains. Use items like upright poles to mark the basic outline of the filters.
Ensure that the surface area of the filter are 33 to 50 % of the surface area of the pond. If there is insufficient space then there is a need for you to decrease the size of the pond. Also mark out if you need space for items such as vortex chambers.
Digging out pond
Dig out the pond as you would with an excavator or manually if you can’t get an excavator in. remember that your pond should be at least 4 feet deep PLUS 1 feet for concrete base (more if you are putting in drainage – allow an additional 1/2 feet).
Note: As per discussed in the earlier chapters, safety is important and make sure that when you excavate a pond this deep that you make sure the integrity of the foundation of the house (if you’re building it close to the house) is not compromised. Also make sure that you always have a second person above ground observing should any mishap happen.
Mark out the filter system at this point. Don’t dig until you know the height of the water level of the pond. Also make sure that you know the exact depth required for the base of the filter.
If the pond is partly above ground the filter base may not be far below the ground level.