Wednesday, July 29, 2009

Plan with Nature

As we approach the limits of water, energy and planetary resources, our built environment will necessarily have to encompass not just the traditional zoning and transportation issues, but will also have to consider the impact that human settlements have on the earth and balance its energies and resources, such as water and materials. The form of the city will need to follow the land and use its natural processes rather than obliterate it. This will involve a highly integrated mapping approach that understands the impact of construction and transit on the land itself, through the interplay of natural forces, water supply, energy supply, adjacencies to transit and supply centers, the issues of sewage and stormwater, sun, winds and rain. There is no longer any isolation of sites from each other and these systems will form structures that respond to each other and integrate with the site's natural character.

In order to create or rebuild the appropriate city forms, there will need to be tremendous amounts of information made available, not just systems of regulation that assume standard conditions. Current planning is making use of Geographic Information Systems which are complex computer models that contain all the information on a site or region, reflecting the natural contours, site orientation, geology and water flows.
"GIS technology, as an expansion of cartographic science, has enhanced the efficiency and analytic power of traditional mapping. Now, as the scientific community recognizes the environmental consequences of human activity, GIS technology is becoming an essential tool in the effort to understand the process of global change."
The way that the city is engineered will need to become very responsive to its particular environment, and minimize the energy, water and waste production that occurs. This tends to dictate "hub" systems, or "distributed power" formations, which means that energy is produced locally and water is recycled locally, a far more efficient way of building that mimics natural systems, while consuming far less.

The way to control the development of urban form to benefit humans and nature is through the use and taxation of property, which determines how much development can be placed in a given area. The formulas for these zones should be tied to a value assigned such that It encourages the most appropriate use and form. One form of this is land value taxation, which taxes the land's underlying value rather than the improvements on the land. Higher values encourage more structure in order to derive profit from more square footage, and lower values relieve the pressures of development in areas that require more open space and landscaping in order to maintain natural systems. This system is percieved as more fair than a patchwork of land use codes, and has been in use in cities in Pennsylvania, particularly Harrisburg. Connecticut has just passed LVT legislation.

A different experiment in zoning, as found in Houston, has shown that policies such as street and block sizes also have a major impact on the appropriate form of the city even as it is unregulated with use zones. The pendulum will need to swing back to human scale, not automobile scale.

If the information about the land is available to developers and designers, and is aligned with codes and policies which are in synch with each other, then effective urban and suburban design can be achieved, and balanced with natural landscape and watersheds that are crucial to sustainable existence. The form of the city can then be planned to mitigate the effects of the built up core with greater areas of land that are functioning natural systems in the immediate region. Energy use can thus go way down if the systems, form and function of a city are in synchronization with the naturally-occurring resources.

Thus, "Design With Nature" becomes not just an arcane mapping study tool, but a practical reality that can be modeled and anticipated.
This can be used in an intelligent way to restore damaged land and watersheds and bring the built form back into balance with the environment.