Dew pond

Taut oak, also called Tauweiher, the freshwater supply used in areas with no other water supply sources.

They gather in the night more condensation than evaporation in the day so that they are filled even in the hottest summer with water. This is due to a special insulation technology, in which the base is sealed with clay loam and a layer of straw. The technique has already been applied in the Neolithic

Taut oak were seen in cross section ( semi-) elliptical, with a flat sole and on the banks of relatively steep slope. created. After the excavation, the walls were smeared with a thick waterproof clay, these lined with a thick layer of reeds or straw as insulation material, it again a second layer of clay. A burn-off led to the firing of the clay to a " buried pot with glaze ." Sometimes straw was used instead of reeds and water-resistant lined with clay or lime and it fieldstone.

The thermal insulation through reeds or straw over the geothermal heat causes the pond water at night cools by radiation faster than the soil surrounding the pond and dew formation of normal humidity rather uses. As a result of nocturnal cooling condensed dew, the water level or at the top of the " pot " ( improved if there grasses grow ) and accumulates in water- pot ..

Has the heat insulation layer wet ( when either the lower or the upper clay layer were leaking ), the insulating layer lost its heat insulating effect and the pond dried up.

Taut oak, there are, among others, in Schleswig -Holstein on mounds, in England ( "dew pond", "cloud pond", " crap pond" ) and in Albania.