Dam Building

When I married Kees, I was warned that he had a thing with water and fish. At that time, this fixation did not get any further than an aquarium and a ‘paludarium´ (a combination of aquarium and terrarium). Now we have 8 hectares of potential forest with a small stream. And streams can be dammed, just like twenty years back on holidays in France...

Since our borehole does not deliver much water, water has to be found, or stored elsewhere, which provided Kees with the perfect excuse to build a dam. After some literature searching, we decided that the dam should be constructed of gabions. A gabion is a box made of cyclone fence which you place where you want it and then fill up with stones. The gabions can be used to build a dam. Gabions are somewhat flexible and therefore do not require the rigid foundation needed for a concrete structure.

We had barely returned to Mariato, when Kees decided that building the dam was more important than putting up the shelves in our house. He had already studied the stream and knew exactly where the new dam was to be built!

The next day we went to Santiago to buy 30 m of 1.80 m high cyclone fence and the day after that we spend carting sand and stones from Mariato beach to our farm. The latter was quite a job. Normally we ask a few Panamanians to help us with these heavy jobs, but all our normal contacts were unavailable. So we did it all ourselves. Six times we loaded the pick up with about 400 liters of sand and 200 liters of stones and offloaded the stuff in the front yard of our property. A liter of sand or stone weighs about 2 kg, so you can calculate for yourselves how tired we were at the end of the day. And don’t forget, at the end of the day we had to walk further and further on the beach to get decent sized stones…

On Thursday we did manage to hire some Panamanians to carry the stones from the front yard to the dam site (the sand is for another activity). We made the gabion in one piece and carried that to the site ourselves. At the dam site, Kees filled up the Gabion with stones. Large flat stones have to be placed on the bottom and along the sides. These have to fit together as closely as possible to minimize leakage. In the centre you can put smaller stones and the whole thing is covered with flat stones. Then the gabion is sewn closed with wire. The whole process is not unlike a three-dimensional puzzle. And one that never really fits if you are using stones from the beach, which are rounded by erosion. Kees added some gravel and coarse sand while filling the gabions to close small openings. A 10 cm pipe was also fitted in so that we can empty the dam when necessary. At the end Kees threw more sand and gravel on the dam to further minimize water seeping through.

So far the water level has risen from ankle deep to almost knee diep! (Kees has long legs). As soon as the current gabion has settled properly in the soil and we have gathered enough courage (in about two months time), we will build another level to further increase the water level of the pond! But first the shelves in our Mariato house.
(photos will be uploaded soon on www.flickr.com/photos/tanagertourism/sets)