In the 1970s, lawmakers introduced waves of environmental legislation across the United States and Canada. The computer-assisted mapping techniques that emerged in their wake would go on to shape the future of geographic information systems (GIS) as we know them today.
As governments began to set new environmental rules and regulations, they realized they would need to step beyond merely visualizing resources, and towards answering precise questions about spatial relationships. How close to public reservoirs should heavy construction be permitted? What constitutes an “at risk” environmental area? To answer such questions, features in the natural world would have to be made commensurable with one another as geospatial data; only then could they be added, subtracted, and analyzed, producing numbers and values that were often more important than the maps themselves. In other words, transforming observations about the world into actionable, enforceable policies required computer processing.
In Massachusetts, the Executive Office of Environmental Affairs (EOEA) was charged with safeguarding public health from environmental threats and preserving the Commonwealth’s natural resources. After its founding in 1975, the EOEA would go on to work with other state agencies to create spatial datasets and maps, informing public policies that still impact us to this day. In dashed circles around wellheads and bright red buffers of suburban tributaries, the maps in this section illuminate early forms of geospatial analysis—many of which remain fundamental components of the modern mapmaker’s toolkit.