When sufficient progress has been made with the excavation work for the pond, it will be necessary to determine the levels. The most important thing to consider is the height that you want the final water level of the pond to be. Every measurement will be taken from that specific point, even the levels that must be determined later like the filter system .
Use a steel reinforcing rod or a length of timber that is at least 2.5 meter long and drive it into the ground close to the outer edge of the dugout area. Mark the desired water level on this pole. Mark also the top level of the pond. It is very convenient on the long run to paint the area between these two marks a bright colour so one can see the different levels from a distance. The next step is to mark the top level of the concrete base. The rest of the markings like the level of the foundation etc. will depend on your choice of base. Use your imagination and paint the areas between the different markings, different colours. The illustration below is an example for the reinforced double base.
The level marker will now be the ruler to use for all the levels of the pond as you proceed. The main challenge is now to get the desired levels on the other side of the pond as well as the area for the filter system. You may have heard or read about various ways to determine levels over the whole width and length of the pond. They will be mentioned here for convenience sake but I have had many frustrating experiences with some of them.
Some people use a length of plastic tubing filled with water. Gravity dictates that the water at each end of the tube will be the same level. To use this method successfully is truly a mission and will stretch your patience to the limit.
The other way to determine the levels is to use a fairly long spirit level with the aid of a straight edge. Most building contractors in South Africa insist on using the spirit level. I must advise against it. Over long distances it is very difficult to use accurately. In a pond where the water level is obviously 100 percent level, is very unforgiving when the pond edge is not build perfectly level. It will remain an irritation for life.
A variation on this is the small spirit level that hooks onto a piece of string. This technique is used widely. The challenge is to make sure that the string doesn’t sag, and the accuracy is not great.
If you can find someone that is willing to lend you a “dumpy level”, you are assured of a perfectly level pond. It can be set up in one place some distance away from the pond and the levels determined. It is the best instrument to use.
A laser level is also a very handy, accurate and easy instrument to use. It is available at most hardware stores and very affordable. In my view it is an investment.
Last Updated on Sunday, 15 February 2009 14:13