Authors: Luna B. Leopold, J. N. Collins, and L. M. Collins. Abstract: Measurements of velocity, depth, discharge, and slope were simultaneously made at ten gages along a natural estuarine channel 19,000 feet in length in Petaluma Marsh, California. Along the study reach the channel decreases from a width of 47 feet at its mouth to nearly zero at its headward extent, with accompanying decrease in depth. Though gage height varies with time in a smooth sinusoidal manner at all stations, this is not true for velocity, discharge, or slope. Originally published: Catena; v. 20 (October 1993).