Carplantis is a quarry of about 50 years old, it was created by sand extraction for the construction of the N33 road in 1960, has water depths of over 14 meters (44ft) with a very diverse bottom profile. In the marginal zones there are many reeds present and some weed but in fewer quantities than the reeds. The entire lake is tree lined with numbers of large Oak, and Birch trees, making the water very sheltered.

A typical sandpit is relatively poor in nutrients, however Carplantis contains large numbers of small native crayfish (these cause little or no trouble when fishing), Swan Mussels, Triangle and Zebra mussels, snails and water fleas. The lake is fed by groundwater from underground wells and rainwater. The water level is stable with only a difference of up to 30cm (1ft) between summer and winter.

The bottom is relatively hard in the shallower zones and becomes softer in the deeper areas. The bottom color is ranging from a dark yellow on the hard areas to a dark grey / green on the softer parts. Good research and the pluming of the fishing spots are essential to get the best out of the swims at Carplantis.