Could it be possible to build a canal from Lannisport to Red Lake to Golden Grove. There has to be more rivers in the Westerlands right?

It’s possible (although very expensive, since it’s 300 miles from Lannisport to Redlake, and politically rather difficult b/c I doubt Highgarden would want Lannister economic infiltration that bypasses Highgarden to boot), but the Silverhill River is right there and Goldengrove is on it, so why not just use that oute instead?