Intrusion of saltwater occurs when the demand or increase in the pumping of freshwater wells is higher than the rate at which freshwater naturally produces. The production rate for freshwater takes time and depends on a few factors such as the climate, precipitation, surface runoff, and temperatures affect the rate at which freshwater accumulates. When over pumping occurs and the underground freshwater process is slow, ocean water replaces the absent ground water and thus areas suffer saltwater intrusion in the aquifers.
Wind powered pumps had been the source of groundwater pumping from the Los Angeles Basin area in the late 1800s, this provided the growing population and agriculture with large amounts of freshwater daily. This continual increase in pumping caused the pressure of the potentiometric level to drop and the earliest intrusion of saltwater was noted by the 1920s.
By the 1950s, Los Angeles created a temporary solution by forming hydraulic pressure ridges or barriers alongside of closely set wells. This procedure would slow the flow of saltwater; however, it has not been very productive in its purpose. (Brian D. Edwards, 2002)
Fresh water is an important component for human survival, without freshwater people