Building over the water would be great but realisticly couldn't happen, especially a flying coaster over water because B&M will not build on water unless its a drainable pool (eg. the Hulk @ IOA.)They could also continue to infill but there is the problem that the water you infill, has to go somewhere else, and there aren't that many places around that they can flood, because the farm isn't particularly big and is an ideal storage space for stuff they don't need.