The document discusses artificial recharge, which aims to augment groundwater reservoirs by modifying natural surface water movement using civil engineering techniques. It aims to maintain groundwater resources, store excess surface water underground, improve saline water intrusion, and remove impurities from wastewater. Common recharge sources are rainfall, roof runoff, canal water, streams, and treated wastewater. Factors like topography, water supply, geology and cost affect recharge projects. Common methods are surface techniques like flooding, basins, streams and ditches, and subsurface techniques like injection wells and recharge pits. Successful projects require source assessment, structure planning, design, monitoring and maintenance.