Water storage

Water storage is a broad term referring to storage of both potable water for consumption, and non potable water for use in agriculture. In both developing countries and some developed countries found in tropical climates, there is a need to store potable drinking water during the dry season. In agriculture water storage, water is stored for later use in natural water sources, such as groundwater aquifers, soil water, natural wetlands, and small artificial ponds, tanks and reservoirs behind major dams. Storing water invites a host of potential issues regardless of that water's intended purpose, including contamination through organic and inorganic means. Groundwater is located beneath the ground surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the water table. There are two broad types of aquifers: An unconfined aquifer is where the surface is not restricted by impervious rocks, so the water table is at atmospheric pressure. In a confined aquifer, the upper surface of water is overlain by a layer of impervious rock, so the groundwater is stored under pressure. Aquifers receive water through two ways, one from precipitation that flows through the unsaturated zone of the soil profile, and two from lakes and rivers. When a water table reaches capacity, or all soil is completely saturated, the water table meets the surface of the ground where water discharge in the forms of springs or seeps. It is also possible to artificially recharge aquifers (using wells), for example through the use of Aquifer storage and recovery (ASR). Groundwater is stored in two zones, one being the saturated zone, or Aquifer, the other is the pore space of unsaturated soil immediately below the ground surface. Soil moisture is the water held between soil particles in the root zone (rhizosphere) of plants, generally in the top 200 cm of soil.