I tried Brugle's idea of a big loop for the water carrier.
It's a simple version, which means, that I didn't grapple with sturdy huts in front of Estates, ..
The loop is 300 tiles long.
People live in 21 Palatial Estates -> 4200
258 Fancy Residences -> 23736
4 1x1 Apartments -> 76 (because of the road, which leads inside the loop)
9 places not occupied -9