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THE COSTS OF
<br />ENVIRONMENTAL DEGRADATION
<br />The economic impacts of development, both pos-
<br />itive and negative, extend much farther than is
<br />commonly appreciated. For many years research-
<br />ers have been concerned about the land, air, and
<br />water pollution effects of low - density develop-
<br />ment. Our present land- consumptive system of
<br />development increases air and water pollution
<br />with both ecological and economic consequences.
<br />While it is difficult to quantify the total economic
<br />impact of the loss of open lands (because the
<br />effects form an interconnected network affecting
<br />industries as diverse as farming, fishing, and
<br />tourism), those losses can be substantial.
<br />Land Consumption
<br />Very few communities have escaped the effects
<br />of strip development and large -lot subdivisions.
<br />It sometimes seems to occur overnight: where
<br />there was a farm field yesterday, today stands a
<br />Burger King, a 7- Eleven, or a Wal -Mart. The pace
<br />has been sometimes fast and sometimes slow, but
<br />relentless, to the point where it is often accepted
<br />as inevitable.
<br />Large -lot residential zoning, often enacted by
<br />communities that would like to preserve open
<br />space such as woo an and farmland, is to a large
<br />Fart—responsible for the hi h levels of land con -
<br />sump ion experience by those communities. In
<br />Maryland, where half of the new construction oc-
<br />curs on agricultural parcels, 73,700 acres of farm-
<br />land were converted to developed uses between
<br />1985 and 1990 (Greer, 1991). A similar acreage of
<br />woodland was also taken for suburban expansion.
<br />By the year 2020, it is estimated that an additional
<br />700,000 acres of open land in the state will be
<br />covered with development. What this means for
<br />local woodland wildlife habitats and for the lo-
<br />cal farming economy are that both are seriously
<br />threatened. In many suburbanizing areas agricul-
<br />ture has ceased to be viable because large, con-
<br />tiguous tracts of farmland are no longer available,
<br />and support services have become nonexistent
<br />(these issues are discussed in greater detail in
<br />Chapter 18).
<br />The Economics of Preserving Open Space 281
<br />Water Pollution
<br />Conversion of land to development affects local
<br />water supplies through the pollution of rivers,
<br />streams, bays, and groundwater. As land is devel-
<br />oped, the area of impervious surface increases,
<br />thereby reducing the volume of water infiltrating
<br />into the soil. Consequently, more water flows off -
<br />site and into rivers and streams. This runoff, com-
<br />monly called non -point source pollution, carries
<br />with it sediment and such pollutants as fertilizers,
<br />pesticides, and motor oil.
<br />Apart from the substances normally recognized
<br />as pollutants, soil erosion can cause serious water
<br />quality degradation. One study by the Maryland
<br />Department of Natural Resources in the Gunpow-
<br />der Falls Basin, a watershed of the Chesapeake
<br />Bay, shows that forestland produces about 50 tons
<br />of sediment per square mile per year. In contrast,
<br />land stripped for construction contributes 25,000
<br />to 50,000 tons per year. This sediment enters the
<br />tributaries of the Chesapeake carrying nutrients
<br />and pollutants that are slowly killing the bay
<br />(Ebenreck, 1988).
<br />How is this pollution likely to affect the econ-
<br />omy? The Chesapeake Bay is an excellent example
<br />of the network of economic impacts related to
<br />open space preservation. The Office of Research
<br />within the Maryland Department of Economic and
<br />Employment Development estimated the value of
<br />Chesapeake Bay to the economies of Maryland
<br />and Virginia at $678 billion (in 1989 dollars). Of
<br />this amount, $31.6 billion is generated annually
<br />from commercial fisheries, activities for the ports,
<br />ship and boat building, ship repair, and tourism
<br />specific to the bay. Water pollution is seriously
<br />harming the commercial fisheries upon which the
<br />regional economy depends, for both the fishing
<br />and tourism industries. The report states that:
<br />Should water quality decline, marine vegetation
<br />continue to die, wetlands be destroyed, and water-
<br />fowl and animal habitats vanish, then that portion
<br />of total land values around the Bay will decline as
<br />well.
<br />Likewise, some — though not all —major water -
<br />related commercial economic activities are threat-
<br />ened by further deterioration of the Chesapeake
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