Water conservation in Curaçao; using traditional earthen dams
The climate in Curaçao is semi-arid to arid. Every century several extended periods of drought occur with practically no rain. A whole system of earthen dams for water conservation was developed since early colonial times. These dams force part of the rainwater into the ground and help maintain groundwater levels; they also help to combat erosion. A large number of smaller dams is more effective than a few large ones. This way ground water levels are influenced over a relatively large area. A few larger ones were constructed in the 20th century but even so these are relatively small; the very largest one having a capacity of 600.000 tons. The next one comes in at 450.000 tons; all the others are substantially smaller. The larger dams are less effective, they store more water above ground in a deeper temporary lake where a larger fraction of the water is subject to evaporation over a longer period of time as compared to a series of smaller dams with the same capacity.
Since most of the food production was local, this system was of the utmost importance. Curaçao is divided in 48 different watersheds (catchment areas). With time the water flows in practically all of these were all extensively dammed, except for the limestone and calcareous areas. Housing developments have lead to the destruction of many dams. There are still a few large ones and about 800 smaller ones which are still functioning. In the past there were at least 1500 of such dams.