求翻译：4、排水工程：以关系到地方排水灌溉和通行需要的通道涵洞为优先施工对象，保证地方道路通行与主线工程施工同步进行。是什么意思？

4, drainage works: the relationship between access to local irrigation and drainage channels and culverts need to give priority to the construction of the object to ensure that local access roads parallel with the main construction.

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4th, dewatering excavation: Take relates the channel culvert which the place draining water irrigation and needs general as first to construct the object, guaranteed the local road passes through with the master line project construction synchronization carries on.

4, discharge: relates to the local traffic needs of irrigation and drainage channel for priority construction of culverts to ensure synchronized local road and the main line construction.

4, drainage works: the relationship between access to local irrigation and drainage channels and culverts need to give priority to the construction of the object to ensure that local access roads parallel with the main construction.