Finding aquifiers under dams

Dams are the most important parts of the flood control systems. Sandboils and leakages can be very dangerous if the river floods. Usually they appear at sand or gravel lenses, where the water can move quickly under or in the dams. The electical resistivity of aquitard layers (clay, aleurit) are usually lower than the aquifiers (sand, gravel), which means that the geoelectrical measurements are suitable to find aquifiers under or in a dam. MinGeo have an 8 chanell geoelectrical instument, which can measure up to 3000 electrode configuration per an hour. The models calculated with such data productivity are highly reliable. Low frequency GPR is also useable to find shallow aquifiers.