They have gaps in them where they cross little natural drainage channels and the lines themselves are not perfectly filled in, with lots of little streaks and uneven coverage.
The rush of water downed utility lines, broke underground drainage pipes and flipped cars that remain Mired in mud.
急流瘫痪了公用线路，冲破地下排水管道，弄翻陷入泥坑的汽车。
3
The whole city drainage system program is as follows: rain water wells road, clay and drain well across the street and drainage inspection wells and underground drainage main lines.