The pumping may put threat to lowering of groundwater level. NIHSA has implemented a programme of drilling new monitoring boreholes for monitoring groundwater level. Timber will last for a long time below the groundwater level. Dolostone settled below groundwater level is less crushed. Hence, timber tends to last for a long time below the groundwater level. Carlsbad Caverns National Park is situated in a bed of limestone above groundwater level. The excavations were difficult because the human structures lay below groundwater level. Rapid changes in the groundwater level along a slope can also trigger landslides. The measurement results were compared with borehole groundwater level measurements and rock resistivity. The change in the groundwater level led to high salt concentrations in the water table. The groundwater level monitoring data are stored at NIHSA headquarters in Abuja. The chamber was located almost at groundwater level, which resulted in high humidity. Groundwater variations are measured by wells as the groundwater level varies over time. Below the groundwater level, dissolved oxygen is lacking even though there is ample water. Reports are available, which show a sinking groundwater level of 1 meter per year.