Yet in one simple form, this kind of land use planning has been practiced for many years in rural America by millions of farmers, who have cooperated with one another to their own mutual benefit in soil conservation programs to reduce erosion and to slow down the wasteful and destructive runoff of precipitation. We noted earlier a pilot urban adaptation of such programs on Pohick Creek on the metropolitan fringe in Virginia, where an effort is being made to develop a whole stream basin in accord with soil conservation principles, not only to avoid future flood damages and sedimentation and pollution but to retain natural areas, living streams, and many of the other features the land had before the city engulfed it. Even with the gaps in present knowledge and the probability that developers and builders are not going to cooperate as fully and eagerly as farmers, it offers much hope. For it may well betide a time when urban planners in general will have the vision and authority, together with the reinforced knowledge, to subject all new development to its basic guiding precept--a respect for the way the landscape works. It is getting to be far more possible now than it was in the past to say, in relation to a given place: "This is how development ought to proceed." In the ring of counties nearest Washington, all of them much lacerated by sprawl that has been gobbling up some 24,000 acres of peripheral countryside each year, respect for the way the vanishing landscape works has been growing by leaps and bounds. The authority to translate it into good practices, however, is much hampered by the complexities of metropolitan reality. Officially endorsed plans exist for these counties, or for parts of them, which show quite a lot of regard for soils and topography and their appropriate use. But frequently these plans are of necessity a mass of compromises. They have had to be adjusted drastically to fit in with existing development, road networks, sewage lines, and such things, which seldom are located in accordance with an ecological ideal. They are encrusted with concepts from older plans not based in landscape principles. Differing views or interests on opposite sides of municipal or county boundary lines may gut them. Money to buy needed open space--the only way to ensure its protection--is usually short. And legal institutions that ought to be on the side of good planning sometimes get in its way.