"Over a period of ten years, simultaneous measurement of storm rainfall and resulting during individual storms were made in small basins in the , California. By simple measurement, without any recording devices, data collected define a relation of basin lag time to drainage area. This lag time, expressed as time between center of mass of rainfall and center of mass of runoff, is a specific measure of some basin characteristics including the effect of . Using lag time relations, synthetic hydrography construction shows the effect of urbanization on peak discharge from a given storm. The method applied to one storm shows that urbanization increased the peak discharge by two fold."