Reinforced concrete reservoir
Reinforced concrete reservoirs are used to store clean water for release on demand. They are usually made of concrete reinforced with steel bars or steel mesh, although some low-cost construction techniques use bamboo or other materials to reinforce the concrete. Reservoirs may also be made of masonry, or ferrocement. Chemical additives are often mixed with the concrete to make it more impermeable to water. Reinforced concrete reservoirs are built at the sit on a solid foundation. If the base is not solid enough, another site should be chosen, or arrangements made to stabilize the construction.
To protect the water from contamination, the reservoir is covered with a roof, usually made of reinforced concrete, but other materials can be used. In the top of the tank an aeration pipe with a screen allows fresh air to circulate in the tank, but keeps rodents and insects out. A manhole in the roof allows access to the tank for cleaning and repairs. Water flows into the reservoir through an inlet pipe above the water level in the reservoir. This prevents back-flow and allows the water to be heard entering the tank. At this point, a chlorine solution is often added for disinfection. Outlets are built a little above the floor of the reservoir, which has a slope pitched down towards one point with a washout pipe for flushing.
