Hi Aaron,
Ah, considering the implementation of a siphon system for water supply is a commendable initiative.
Although precise data on the steepness of the river may not be readily available, we can make some informed assumptions based on general characteristics of rivers and the terrain in the region. Mondulkiri, being a province in Cambodia, generally features varied topography, including both flatlands and hilly regions.
Given this, we can infer that the Mekong River passing through Mondulkiri might have sections with varying degrees of steepness. This resource “rom Chiang Saen to Kratie, the river has a moderately steep slope of about 0.25 m/km, on average. Downstream from Kratie, the riverbed is relatively flat on the Mekong floodplain and Delta, with an average slope of 0.03 m/km” Kratie is a close by province, and you can make assumptions for Kratie instead.
Hope that helps,let us know if you have further questions
Sai Rupa Dev