乡宁县谭坪公社谭坪生产大队,近几年来在东洋沟修淤地坝五十八座,淤成坝地一百三十八亩,亩产三百五十斤以上。去年春季以前修的二十八座新坝,经过五月份的两次大雨(第一次三十个小时,降雨一百二十毫米,第二次三十八小时,降雨一百五十毫米,暴雨强度最大时达每分钟一毫米以上),全部淤成坝地,仅有一座旧坝田面出现了一个陷窝,雨后及 Tanping Tanning Township commune Township Ningxian production brigade, in recent years in Dongyangou ditch dam fifty-eight, silt into a dam of 388 acres, more than three hundred and fifty pounds per mu. Twenty-eight new dams repaired before last spring after heavy rains in May (the first thirty hours, 120 millimeters of rainfall, the second thirty-eighth hour, 150 millimeters of rainfall, When the intensity of the storm reaches a maximum of one millimeter per minute), all of them are silted into dams, and only one of the old dams has a dimple in the surface. After the rain and