Hello! In order to calculate wave run-up for a reservoir, I need to determine the average reservoir depth along fetch line (D).... Does anyone know how can I calculate this depth? In some book I have read that D is the average reservoir level along the direction of wind blow, and it is assumed to be half of the initial reservoir, D=0.5Ho, but only for 20ft <Ho<35ft. In my case the initial reservoir level is more than 35ft. Another books and works do mention of a Engineer Letter of the U.S. Department of Corp of Engineers, named ETL 110-2-221: Wave Runup and Wind Setup on Reservoir Embakment. But I have been unable to get this book. I would appreciate any suggestion or advice. Thank you very much!