Which maintenance issue most commonly reduced flow rate by increasing surface drag in ancient Mesopotamian canals?

💡 Explanation

When Mesopotamian canals experienced reduced flow, silt deposition occurred because suspended sediment settled over time, increasing the roughness of the canal bed causing greater surface drag. Therefore, silt deposition reduced flow, rather than vegetation, cracking or burrowing, which would induce different hydraulic effects such as blockage and structural failure.

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