Crossing beneath a channel – terminology for a pressure conduit laid below a stream/canal A closed conduit carrying water under pressure beneath a natural stream or irrigation canal is commonly termed:

Introduction / Context:
Water-supply and irrigation networks often need to cross valleys or existing waterways. When the carrier pipe dips below the obstacle and runs full under pressure, several synonymous field terms are used.

Given Data / Assumptions:

• Closed pipe flowing full under pressure below an obstruction.
• Entry and exit connected to the distribution main or canal.

Concept / Approach:
The term “inverted syphon” is standard. The same arrangement is also called a depressed pipe or sag pipe in practice, reflecting its profile. Because all listed terms refer to the same configuration, the inclusive option is correct.

Step-by-Step Solution:
Match the description (pressure conduit below obstacle) → inverted syphon.Recognize common synonyms → depressed pipe, sag pipe.Therefore, select “All the above”.

Verification / Alternative check:
Design drawings and specifications often annotate the same crossing with any of these synonyms depending on regional practice.

Why Other Options Are Wrong:
Each single term is correct but incomplete relative to the question’s inclusive phrasing; the comprehensive choice is “All the above”.

Common Pitfalls:
Confusing an inverted syphon with a culvert; a culvert conveys external drainage and usually runs partially full, not as a pressurized carrier for the supply line.

Final Answer:
All the above