There is a blemish on the Swords and Glory map, on the line between hexes 3013 and 2914, an ink smudge that I have chosen to interpret as a series of lakes. :-)
My assumption is that these shallow lakes change in water level throughout the year. I assume the sakbe road that runs across them is similar to that that runs down to Penom or to Purdimal. That is, it is of wood supported upon piles.
Where the U Bien Bridge comes into the picture is I think the local communities are linked to the road and to each other by similar bridges. U Bien bridge is located in Myanmar and is about 1.2 km long, crossing a large lake. It was built in the 1800's from teak logs from a palace that was being abandoned.
Shown below are some of the screenshots showing some mapping progress. These are actually 3-4 weeks old and I have progressed beyond this point in certain aspects. They show the shallow lakes plus the "Chega Lakes" which I invented to account for the winding path of the unfinished sakbe road that runs south from Hauma. They also show my attempts to locate the village of Nisuel and Jikutlar fief, which appear in one of the solo game books. IIRC, Nisuel is the seat of the Golden Sunburst Clan. In the game book it is stated to be 100 tsan north of Jakalla and Jikutlar fief is located over a 100 tsan further north than that. Which places it approximately where I have drawn it. I'm not sure if that is what was intended as it is stated as being within the Mssuma river delta, which it is not. If it were located two hexes north I think it would be but even though a hex is 100 tsan across, that is not the same as being a full 200 tsan to the North!