Monday, March 28, 2016
John R. Nolon
Distinguished Professor of Law, Pace Law School
Counsel, Land Use Law Center
At their inception, comprehensive planning and zoning focused intensely on capital infrastructure: streets and roads; water and sewer; and electric lines and other utilities. These served development parcels with their buildings, driveways, and other hardscapes. Streets and roads were classified by traffic load and function with local streets, secondary streets, collectors, and arterials governing the flow of traffic in the public interest. When viewed from 10,000 feet, this gray infrastructure is clearly visible: a thoughtful pattern of connectivity to serve the built environment. This result was one of the principal objectives of early zoning.
Over time, evolving concerns with flooding, public safety, wetland and watershed protection, the urban heat island effect, and the loss of open space and its ecological services gave rise to mapping and preserving the green infrastructure of a community. These plans connect the natural assets of the community in much the same way that planners design a locality’s gray infrastructure. Planners concerned with green infrastructure calculate the current green space coverage and connectivity and then figure out methods of increasing it to a healthy amount of the surface area of the community. This process ensures that an adequate percentage of the land is sheltered and shaded, with its soils held intact and its ability to absorb and retain water preserved, if not enhanced. Water and wildlife, like vehicles and people, need to travel through connected paths and landscapes.
The broad view of green infrastructure envisions it as a strategy for adapting to climate change, bettering air quality, lowering heat stress, creating greater biodiversity, conserving energy, providing ecological services, sequestering carbon, preserving and expanding habitats, enhancing aesthetics, increasing property values, and improving the livability of neighborhoods.
The elements of green infrastructure include green roofs; planters; rainwater harvesting; street trees; preserved open space on building sites; natural vegetated corridors and swales; permeable paved areas accented with green features; xeriscaping; private gardens and public parks; detention basins; bio-retention ponds and rain gardens; green building facades; and greened medians and edges along streets, paths, and rail lines. Parking lots can be greened by adding trees and using permeable surfaces that allow infiltration and permit vegetative growth. When seen from the air, the community with robust green infrastructure appears more connected naturally; ideally, the green and the gray are complementary.
All of these elements of green infrastructure can be built into local planning, zoning, and land use regulations. Cities can begin green infrastructure planning at the same time they create and implement their plans for building and development to accommodate anticipated increases in population. The local comprehensive plan can be supplemented by the addition of a green infrastructure component that grows out of this planning process. Then, zoning and land use regulations can be amended to implement the green infrastructure component’s vision.
An adopted overlay zone can trace the contours of the green infrastructure plan and, within that zone, local review boards can condition approvals, or use zoning incentives, to implement it. Landscaping requirements, along with erosion and sediment controls, can be added to subdivision and site plan regulations. Developers can be required to include green features in, on, and around their buildings. They can also be required to pull development back from floodplains and wetlands and to leave room on their sites for open space. They can pay impact fees where they cause the destruction of vegetated areas and the proceeds can be used to pay for the greening of nearby public spaces. Local and state capital budgets can support street trees, medians, parks, the greening of publicly-owned buildings and sites, and open space preservation.
What the architects of green infrastructure do is use these land use techniques in an integrated fashion; they plan the entire community so that its natural functions are connected and create healthy and livable neighborhoods. In communities that have made green infrastructure a priority, zoning achieves objectives not understood when it was invented 100 years ago.
For more information, see John R. Nolon, Enhancing the Urban Environment Through Green Infrastructure, in Protecting the Environment Through Land Use Law: Standing Ground (Environmental Law Institute ed., 2014), http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2724050.
Links to previous posts in the Zoning Centennial’s Series:
Part 8: Regionalism and ‘Wistful Hoping’
Part 11: Designing Density