Model with filter that is above ground for regular maintenance. Ideally both filter and cistern reservoir would be built on a slant, at 100 feet elevated level to maximize gravity flow and the avoid the expense of a pump. The model also can be built in a round shape. Providing adequate water for a family off-grid, or during a drought or emergency can be solved with an underground cistern. Many farmers use bulk water storage, such as ponds. Some cisterns may have been in use since 2500 BC, for over 4500 years. Cistern water can be used on an off-grid homestead for housecleaning, showering, handwashing, for cooking and drinking when properly filtered, dish washing, toilets flushing, to irrigate gardens and crops, and to water livestock. CISTERN OPTIONS •61,440 gallons = 9075 cu-ft = 232,575 liters. Rain water collection •3200 square foot roof total -- 61,440 gallons per year.