Reminds me of Cambodia, where even in the capital and most major cities, the greywater and sewage go to the same massive uncovered open canals. They are usually called sh?t rivers for obvious reasons, and property is usually available for very cheap on the sh?t riverside. There are even many popular cafes on these strips, but can't say I ever dared gamble eating at places like this.
Congrats on the enclosed system, hopefully it will help cut down on mosquitoes.