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Water Portal / Rainwater Harvesting / Groundwater recharge / Permeable rock dams

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[[Image:perm rock dam icon.png|right|80px]]

[[Image:PermeableRockDam2.JPG|thumb|right|200px|堆石透水坝Permeable rock dams, 流水flowing. Photo: [http://il.water.usgs.gov/asian_carp/images/IM_Canal/3-Illinois%20and%20Michigan%20Canal%20Flow%20Barrier_recent.JPG USGS.]]]

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堆石透水坝由低矮的长形石墙构成，有数个高势位置，长度贯穿整个谷底。这样的构造能使水道侧部形成径流。这种洪水灌溉方法能分流并保留洪水，促进庄稼生长，同时控制沟蚀。堆石透水坝可被视作为一种“梯田干谷”，虽然后者通常用于更干旱地区中的水道内的结构。Permeable Permeable rock dams consist of long, low rock walls with level crests along the full length across valley floors. This causes runoff to spread laterally from the stream course. This is a floodwater harvesting technique that spreads and retains floodwater runoff for improved crop growth, as well as controls gulley erosion. Permeable rock dams can be considered a form of ‘terraced wadi’, though the latter term is normally used for structures within watercourses in more arid areas.

堆石透水坝Permeable rock dams provide a more effective and popular technique for controlling gully erosion than gabions. Permeable rock dams, in addition to the effective control of gullies, have resulted in considerable crop yield increases behind the dams. Gullies are rehabilitated by the deposition of silt behind the dams, increasing the depth and quality of the soil immediately behind the dam as a result of the deposition of fertile silt. They have also improved the amount of moisture available for crops. Yields of sorghum from land restored with permeable rock dams range up to 1.9 t/ha compared with a yield of 1 t/ha from equivalent, untreated land. Other crops planted behind permeable rock dams include rice (on heavy soils), pearl millet and peanuts.

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