居住人口的持续递增,必然带来城市(镇)占地面积的扩张,更多的地表会被硬化,导致暴雨来袭时破坏性更加严重。若城市(镇)区域的地表雨水和生活污水,排入当地的天然水域(湖泊和河流),对雨水带来的侵蚀作用加以管控,成为一个紧迫的、急待解决的大问题。因为暴雨径流会引起严重的水土流失,并对基础设施造成破坏和损害,也可能威胁到居住环境。北达科他州(North Dakota)是美国五十个州之一, The continuous increase of living population will inevitably lead to the expansion of the area covered by the city (town), and more of the surface will be hardened, resulting in even more devastating consequences when the storm strikes. If the surface rainwater and domestic sewage in the urban (town) area are discharged into the local natural waters (lakes and rivers) to control the erosion caused by rainwater, it becomes an urgent and urgent issue that needs urgent solution. Because of stormwater run-off can cause serious soil erosion and damage to infrastructure and damage, may also threaten the living environment. North Dakota is one of the 50 states in the United States,