Xekong Basin Hydrology Info - by Hobo Maps - Go to Hydropower Projects Page - - - Home
This web page is about hydropower projects in the rainwater catchment basin area of the Xekong (Sekong) river in Xekong & Attapeu provinces, southern Lao PDR.
In 2026 we can see 24 hydropower projects in the Xekong Basin map below that have completed projects or are in development. Most projects plan to export the majority of their output to Thailand, Vietnam or Cambodia.
Mainstream Xekong (Sekong) river in 2026 is still the last free-flowing major tributary of the Mekong with unrestricted ability of fish to migrate the entire length. It now seems that ongoing construction of the Xekong 1A Downstream Hydropower Project will block the entire river when completed and create a reservoir above the dam. Experts say that even if fish could somehow bypass the dam structure, the calm waters of a reservoir woud seriously disturb traditional migration and spawning patterns.
A Natural Heritage Institute study (The Study) was done in 2018 to provide the Lao government with lower negative-impact hydropower alternatives to new dam approvals on the Xekong river and its tributaries. The study encouraged the Lao government (GOL) to be proactive in the selection and prioritizing of approved projects and move forward from a reactive approach.
The Study gave the GOL specific priority project options that would encourage and enable proactive planning for new projects, basically trying to reduce fish migration disruptions, minimize relocations of people and limit sediment flow changes.
Negative impact chart below with mitigating suggestions.
The Study ranked 28 projects in the Xekong Basin (maps below) according to perceived negative impacts of each and went further to describe and encourage specific hypothetcal new projects as alternatives with less negative impact.
Charts below from The Study place new hydropower projects into ranked groups (Tier One to Tier Five) according to the project's negative impacts.
Xekong Basin Impact Priority List
The Study's hypothetical new alternative projects as seen in charts above are listed below with links to our separate web pages for Houay Axam & XeLon as examples:
Houay Chalelu 1
Houay Pache
Nam Pa
Nam Pouang
NH1 Site B (Natural Heritage Institute 1)
NH1 Site C (Natural Heritage Institute 1)
NH1 Site D (Natural Heritage Institute 1)
Phak Houay
Also see another study in 2018 led by International Finance Corporation (IFC) that proposes a Master Plan for approval of new hydropower projects - "Final Inception & Scoping Report of the Cumulative Impact Assessment and Management of Renewable Energy Development in the Sekong River Basin, Lao PDR".
Also see Xekong Dams Impact Study by International Finance Corp. Annex
Elevation comparison stats below for Houay Axam, XeLon & XeKong 5 hydropower projects.
