<P> Quarries in level areas with shallow groundwater or which are located close to surface water often have engineering problems with drainage . Generally the water is removed by pumping while the quarry is operational , but for high inflows more complex approaches may be required . For example , the Coquina quarry is excavated to more than 60 feet ( 18 m ) below sea level . To reduce surface leakage , a moat lined with clay was constructed around the entire quarry . Ground water entering the pit is pumped up into the moat . As a quarry becomes deeper , water inflows generally increase and it also becomes more expensive to lift the water higher during removal ; this can become the limiting factor in quarry depth . Some water - filled quarries are worked from beneath the water , by dredging . </P>
<P> Quarries in level areas with shallow groundwater or which are located close to surface water often have engineering problems with drainage . Generally the water is removed by pumping while the quarry is operational , but for high inflows more complex approaches may be required . For example , the Coquina quarry is excavated to more than 60 feet ( 18 m ) below sea level . To reduce surface leakage , a moat lined with clay was constructed around the entire quarry . Ground water entering the pit is pumped up into the moat . As a quarry becomes deeper , water inflows generally increase and it also becomes more expensive to lift the water higher during removal ; this can become the limiting factor in quarry depth . Some water - filled quarries are worked from beneath the water , by dredging . </P>
where does the water come from in a quarry
where does the water come from in a quarry
shallow groundwater surface water
shallow groundwater surface water