Quantity:
• The quantities of available surface water are depend upon rainfall.
• In India rainfall is sufficient and considerable,therefore we know scarcity of water in these surface sources.
• Since, rainfa is not uniform comsiderable variations in the available flow do occur during the years.
• The available flow in a stream channel or a river may be 2 types to be controlled or to less fulfill the demand.
• Storages reservoir provide good menas of storage utilizing rain water.
Quality:
• The rainwater through pure in the begining gets considerably polluted till it reaches the level.
• During precipitation and run off lot of organic as well as inorganic impurities gets added along with sewage and industrial waste making it contaminated.
• Inorgamic impurities like salt,clay etc getsbadded due to erosion from beds of stream channels.
• Organci impurities gets added in the form of vegetable oils,dead organic matter etc.
• Inorganic suspended water in rivers or streams gets settled along with time.
• Surface waters are however generally soft and less corrosive than ground water.
• On the whole it can be stated that the surface supplies are generally contaminated and cannot be used with minor treatment or without any treatment.
• Water treatment plan are needed to treat the water before supply to the public.
