I have a DA in for a granny flat and it has been queried because of stormwater drainage problems. In short I am at the top of the block, my neighbour is lower than me and is a waterfront. The council has asked that a stormwater plan be submitted and that an easement be built for stormwater down to the waterfront. The only problem is the easement has to go across the neighbour's property-the very neighbour who objected to the DA. Are they legally obliged to allow me to put the easement across their land? If not, what are my options for the DA under Property Law and further development of my existing dwelling? Any thoughts would be appreciated.