Still, compared to space needed for desalination, it's not obvious that the current scheme uses less area (I do assume you can still do some things, like hiking

Still, compared to space needed for desalination, it's not obvious that the current scheme uses less area (I do assume you can still do some things, like hiking, in most of this area though) : "One of its largest watershed protection programs is the Land Acquisition Program, under which the New York City Department of Environmental Protection (DEP) has purchased or protected, through conservation easement, over 130,000 acres (53,000 ha) since 1997"