AS 7637水文和水力学描述了铁路基础设施设计和评估的水文和水力学要求（功能、性能、设计约束和风险属性），涉及所有形式的排水和洪水易发区域。该标准提供了一个框架，以促进轨道排水和水道交叉口的设计、施工、调试、维护、监测和退役的一致性和效率。 本标准的范围涵盖公共和私人铁路、铁路排水系统以及影响铁路走廊的任何其他排水相关工程。 路基对轨道性能的重要性与钢轨和道碴相同。 本标准主要涉及地表和地下排水系统的水力设计，包括河流和泄洪道交叉口、涵洞、管道、渠道、坑和格栅。

The AS 7637 Hydrology and Hydraulics describes the hydrologic and hydraulic requirements (functions, performance, design constraints and risk attributes) for the design and assessment of railway infrastructure in relation to all forms of drainage and flood-prone areas. The Standard provides a framework that promotes consistency and efficiency in design, construction, commissioning, maintenance, monitoring and decommissioning of track drainage and waterway crossings. The scope of the Standard covers public and private railways and railway drainage systems on a whole of life basis, and any other drainage related work affecting the rail corridor. The subgrade is given equal importance for track performance as rail and ballast. This Standard addresses primarily the hydraulic design of surface and sub-surface drainage systems including river and floodway crossings, culverts, pipes, channels, pits and grates.