According to Wikipedia, a tunnel is an underground or undersea passageway. It is dug through surrounding soil, earth or rock, or laid under water, and is usually completely enclosed except for the two portals common at each end, though there may be access and ventilation openings at various points along the length.
According to the American Society of Civil Engineers (ASCE), understanding energy relationships in pipe flow systems is fundamental to safe and efficient hydraulic design. The Hydraulic Grade Line (HGL) represents the elevation of pressure head in a pipeline and indicates the height to which water would rise in a piezometer connected to the system. In civil engineering practice, evaluating the HGL is essential for designing water distribution and sanitary sewer systems, as it helps engineers assess pressure conditions, prevent low-pressure zones or surcharging, and ensure reliable service throughout the network.
According to the City of Waxahachie water system standards, dead-end water lines must be minimized and provided with approved flushing mechanisms to maintain water quality.
According to the City of Waxahachie drainage standards, culvert headwalls and wingwalls must be aligned with flow direction to prevent erosion and improve hydraulic performance.