How long should gaging stations be operated?

During the past 50 or 60 years, the U.S. Geological Survey Surface Water Branch, has operated 12500 stream gaging stations, about half of these are active today. Those discontinued were found to be either excess or correlations with other stations could supplement the data without serious damage to the records. Consideration is being given towards this procedure at many stations. The benefit-cost ratios are being studied, where the operation and maintenance costs have gone up. The cost-benefit ratio is an important factor in how long a station should be operated. Primary stations on main rivers will, of course, be maintained. Examples of statistical methods employed are described and illustrated graphically. Optimum benefits occur in the first 6 years with maximum benefits occurring in about 15 years.The paper is discussed by Mr. Perry M. Ford.