The heading, for the section on waterways, is a simple pictograph of a stream.
For image credits, please see below.
Image Credits:
Indus Script Signs with Numbers: List of Sign Variants: Iravatham Mahadevan, 1977: The Indus Script: Texts, Concordance and Tables: The Director General Archaeological Survey of India.
Indus Script Signs without Numbers: Lynn Fawcett, 2018 - 2020.