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Green Development Literature Search

Literature Summary and Benefits
Associated with Alternative Development Approaches

The Benefits of Green Development

Introduction

Economic analysis is often difficult because the costs and benefits of Green Development are intangible in many cases (i.e., environmental, social). Depending upon multiple factors in any given situation, the outcome of a cost/benefit analysis will vary. Several developments based on green approaches are already under construction. The following discussion highlights the economic benefits and costs connected to green development. The discussion is organized by issue (development costs, property values, etc.), however, many of these overlap. Each section describes the economics of green development and includes examples to further characterize specific issues. The following analysis is designed to identify potential costs and benefits for consideration on an individual project basis.

Modes of Transportation/Traffic

Greenways can serve as alternative transportation routes for commuting to work or school, bicycling or walking to local businesses or restaurants, visiting parks and recreation sites, or sightseeing. Trails can often be designed in conjunction with utility corridors and pipelines, thereby reducing site preparation costs to the developer (Florida Greenways Commission, 1995). A Maryland Greenways Commission survey found that 21 percent of those interviewed would use such a trail system for commuting two or three times a week (Maryland Greenways Commission, 1995). As a result of decreasing road congestion, greenways can also decrease the cost of pollution.

Low-density development, as opposed to green, more compact development patterns, is "best suited to meet the needs of the automobile, not the needs of the city or the citizen" (Gersh, 1996). According to information compiled by the Smart Growth Network, the average household trip increased from 7.9 to 9.0 miles from 1983 to 1990 (ICMA et al., n.d.). At the same time average vehicle miles traveled per household rose 29 percent with each household generating an average 11 car trips per day. This can be attributed to urban sprawl. People are moving to the suburbs and commuting longer distances to their workplace. Not only does this increase air pollution and the costs to combat it, but it also takes a toll on personal time. Time spent commuting is time that could be spent elsewhere.

Because of their gridded street pattern, neo-traditional designs typically require an investment in 20 to 25 percent more streets than conventional development (Bookout, 1992). However, because neo-traditional development focuses on streets designed "to move people, not cars," streets in these designs are narrower. In addition, by comparison, low-density designs require more access roads (i.e. impervious surface) to connect residents with commercial and employment centers.

In addition to reducing impervious area and related stormwater flows, narrow streets, combined with a gridded road pattern are designed to reduce vehicle speeds, improving safety and making the streets more accessible to pedestrians and cyclists. A 1996 national home buyer's survey revealed that nearly three-fourths of all buyers would pay more to live in a community "where I can walk or bicycle everywhere" (Harney, n.d.).

In California, local fire departments expressed concern that neo- traditional streets are too narrow ("Neighborhoods Reborn," 1996). However, a test run in Laguna West, a neo-traditional development south of Sacramento, proved that the streets are easily accessible to firefighters and their equipment.

Green development approaches also suit pedestrian needs by better integrating employment, residential, and commercial activities so that walking distances are measured as opposed to car miles. For example, developer Buddy Milliken is designing Woodsong, in Shallotte, North Carolina to include a shopfront district, assisted care facility, and a restaurant in the community, all within a four minute walking distance (Milliken, 1996). These facilities will provide services and jobs to the community, while decreasing air pollution from vehicle emissions. In addition, a school and a golf/pool club will be located within a 5-10 minute walk from the community.

A March 1994 study conducted by the Transportation Management Association Group/City of Brentwood for the Federal Transit Administration found that the presence of on-site amenities (e.g., food and bank services) located at two corporate headquarters reduced dependence on personal vehicles (Federal Transit Administration, 1994). The study showed that the mean weekly miles traveled decreased by up to 3,161 total miles, or approximately 14 miles per person. Based on the patterns evidenced by the 179 study respondents, in a 220 day work year, on-site amenities could reduce greenhouse gas emissions by 25 tons. Drawing from the study's results, a green development approach can avoid the monetary and environmental costs associated with vehicle travel.

Green development approaches can incorporate mass transit. For example, San Francisco-based Calthorpe Associates promotes what they call the "pedestrian pocket" concept which clusters housing, retail space, and offices within a quarter-mile walking radius of a transit system (Bookout, 1992).

Displaced Agricultural Land

Green development approaches that concentrate development in urban centers avoid the costs associated with displacing agricultural land. Low-density development reduces revenues from agricultural crop production and destroys wildlife habitat. Between 1982 and 1992, 532,000 acres of Colorado's farmland was developed commercial or residential (Gersh, 1996). Similarly, in Utah, where the amount of developed land increased by 25 percent during the same time frame, Defenders of Wildlife reports that 200 plants are now considered to be imperiled.

In addition to the loss of farmland and habitat, there is an added cost to the developer. A recent New Jersey study comparing two development plans, one compact and one sprawl, showed that the sprawl option would require the developer to purchase an additional 90,000 acres of prime farmland (Ewing, 1994).

Taxes

A study of nine counties in northern Virginia showed that residential development in rural areas costs more to serve than it generates in tax revenue ("Two Possible Futures," 1992). More specifically, farms generate $1 in revenue for every $0.21 of services needed while rural development costs $1.20 in services for every $1 they generate. Revenue shortfalls resulting from the conversion of agricultural land to development must be compensated by reducing existing public services, raising taxes, or by attracting additional commercial revenues (American Farmland Trust, 1986).

Typically, in conventional development patterns, infrastructure costs are not fully passed on to the consumer in the purchase price (Frank, 1989). Because low-density developments require more services to be extended into rural areas, localities are primed to face revenue shortfalls. In contrast, green development approaches concentrate development near downtown areas, requiring far less public spending because they can rely on existing water and sewer lines, roads, and other municipal facilities. In Loudoun County, Virginia, an American Farmland Trust study determined that the average annual revenue shortfall would be roughly three times as large ($2200 per dwelling) for a low-density development as compared to that of a high-density development ($700 per dwelling) (American Farmland Trust, 1986).

According to Rick Rybeck, staff attorney to a D.C. Councilmember at Large, taxes can be used as an incentive to develop land in the neo-traditional, high-density style (Rybeck, 1996). A property tax reform that reduces tax rates applied to building values while increasing the tax rate applied to land values will encourage development as a means to generate money to pay land taxes. Because land values are highest adjacent to existing infrastructure, these lands will offer the greatest economic incentives for development. The City of Pittsburgh demonstrates the effects of such a tax reform. Until the late 1970's, Pittsburgh taxed buildings at half the rate it taxed land values. This led to greater development within city limits than in suburbs. Today, Pittsburgh has revised the tax on buildings to one-sixth that of land. Other Pennsylvania cities using a similar tax split have experienced the same results. Using this type of tax incentive helps to avoid the costs of extending infrastructure to more rural, low-density developments.

Infrastructure and Public Services

Green development approaches concentrate development, reducing the need for additional infrastructure. In his comparison of alternative development patterns, James E. Frank focuses on the costs of streets, sewers, water systems, storm drainage, and schools at the neighborhood level, while associating the costs of providing highway, sewer, and water links at the regional level. Based on this approach, he concluded that the total cost to serve low-density sprawl development (three dwelling units per acre) would be more than $39,600 (1992 dollars) per unit (Chesapeake Bay Program, 1993). This cost would increase with distance. For example, if the unit was 10 miles from facilities or major employment centers, the cost would increase an additional $16,500. In addition, decreasing density also increases cost. At a density of one dwelling unit per 4 acres, capital cost per unit increases to $87,700 contiguous and $104,000 if located at the 10 mile distance.

Upon examination of infrastructure issues related to neo- traditional development in Loudoun County, Virginia, the American Farmland Trust notes that locating residences and schools in closer proximity greatly reduces school transportation costs (American Farmland Trust, 1986). For similar reasons, Buddy Milliken, developer of the neo- traditional Village of Woodsong in Shallotte, North Carolina notes that compact, high-density developments will provide a savings in law enforcement costs (Milliken, 1996).

The American Farmland Trust study adds that "If a county government seeks to estimate more accurately the net public costs of residential development in the future, it should consider compiling data for some of the major cost and revenue categories..." (American Farmland Trust, 1986). The study specifically notes the need for density-related data on law enforcement, fire and rescue services, and health and welfare costs.

Milliken also observes that although impact fees are structured according to what it costs localities to administer programs, it is common that the impact fees assigned to commercial endeavors tend to support residential plan review, project inspection, and other types of administrative services. Because neo-traditional designs tend to have lower infrastructure demands, the need for administrative review and the associated impact fees decrease, making it more likely that the fees will reflect true costs (Milliken, 1996).

Development Costs and Savings

Residential

Green, high-density developments are more cost effective to develop. In terms of investment, a 1974 estimate found high- density investment fell 44 percent below that needed for low- density, sprawl development (Real Estate Research Corp., 1974). More recently, an analysis completed by Robert Burchell and others at Rutgers University for the State of New Jersey compared typical development with a "planned development" alternative that would include a range of densities and housing types similar to green development patterns (Gersh, 1996). Projecting from 1990 to 2010, the analysis concluded that planned development could save taxpayers $9.3 billion in avoided capital, operation, and maintenance costs for roads, schools, and utilities. Meanwhile, 175,000 acres of land would also be saved.

Many studies have compared the costs associated with various development patterns. The South Carolina Coastal Conservation League (SCCCL), assisted by the Westvaco Development Corporation, compared the costs of developing a 96-acre parcel in a conventional pattern to the cost of developing the parcel using a high-density development pattern. The conventional development consisted of 242 single family homes on quarter-acre lots, a density of four units per acre, the highest density allowed in most residential zones ("Living," 1993). The high- density plan consisted of 333 homes with a mix of single family, duplex, quadriplex, and single-family homes built on third-acre lots, creating an average density of 6.5 units per acre. In the high-density development, 240 residences were placed within walking distance of a bus line, thoughtful planning considering that bus service is considered workable when density reaches 6 or 7 units per acre.

The study found that the costs of developing the conventional plan would be $26,000 per lot, compared to $16,000 per lot for the high-density plan. The cost savings in the high-density development are primarily attributed to savings in per-lot land costs and site preparation costs such as excavating, landscaping, grading, and paving. These cost-savings would be passed on to buyers. A homebuyer looking to purchase a 1,500 square-foot home in the conventional development would pay $95,000, while a home of the same size and quality would cost $82,000 in the high-density plan, a savings of 14 percent.

In general, there are three main components of residential development infrastructure: 1) roadbuilding; 2) storm drainage; and 3) water and sewer service (Schueler, 1995). This infrastructure constitutes approximately half the cost of residential subdivision construction. High-density development typically reduces infrastructure demands. For example, road length can be cut by 50 to 75 percent. In addition, as previously mentioned, narrower road widths reduce road surface area by 25 to 35 percent. Considering that each linear foot of road constructed costs an average of $100, high-density development patterns can produce significant cost savings. Table 1 provides examples of the unit cost for development infrastructure (Schueler, 1995).

Table 1.
Unit costs of subdivision development

Subdivision Improvement	Unit Cost
Roads, Grading	$22.00 per linear foot
Roads, Paving (26-foot width)	$71.50 per linear foot
Roads, Curb, and Gutter	$12.50 per linear foot
Sidewalks (4 feet wide)	$10.00 per linear foot
Storm Sewer (24-inch)	$23.50 per linear foot
Driveway Aprons	$500 per apron
Parking Spaces	$1,100 per parking space ($2.75/sf)
Clearing (forest)	$4,000 per acre
Sediment Control	$800 per acre
Stormwater Management	$300 per lot (variable)
Water/Sewer	$5,000 per lot (variable)
Well/Septic	$5,000 per lot (variable)
Street Lights	$2.00 per linear foot
Street Trees	$2.50 per linear foot

Adapted from Site Planning for Urban Stream Protection, December 1995, prepared by Tom Schueler of the Center for Watershed Protection for the Metropolitan Washington Council of Governments.

Commercial Development

Green development practices are cost-effective for commercial businesses developing or redeveloping office space. Environmental watchdog group INFORM showed that incorporating green practices such as motion sensing light fixtures and recessed lighting can save energy and money. INFORM worked with architects from Croxton Collaborative to renovate its new 9,127 square-foot office space in New York City using green practices. In addition to creative lighting, the renovation relied on green practices such as solution-dyed carpet that conserves water in the manufacturing process and exterior-grade plywood to reduce formaldehyde emissions. All told, by redeveloping the office space using a green design, INFORM paid only $38 a square foot to renovate 27 percent less than the $52 per square foot renovation cost common for office construction in the city (Building Design, 1995).

Planning

States have already begun to incorporate green development principles into their statewide development plans. In 1986 the New Jersey Office of State Planning (OSP) was formed to create a State Development and Redevelopment Plan for New Jersey (Chesapeake Bay Program, 1993). Local municipalities revised their zoning ordinances and master plans to reflect the OSP plan, while OSP made changes to the plan to help make it compatible with local ordinances.

The result of this effort was the Interim State Development and Redevelopment Plan known as the IPLAN Communities of Place. Issued in July 1991, the IPLAN supports development of population centers, noting that "centers are compact forms of development that, compared to sprawl development, consume less land, deplete fewer natural resources and are more efficient in the delivery of public services" (Chesapeake Bay Program, 1993). The IPLAN encourages development of five types of population centers: urban centers, towns, regional centers, villages, and hamlets.

To address questions regarding the ability of the IPLAN to produce its desired economic, social, and environmental benefits, OSP conducted a comprehensive impact assessment that compared the results of IPLAN development with those of the current development plan, known as TREND. Table 2 summarizes the major impacts forecast by the study for IPLAN and TREND development. The table shows that land consumption and water, sewer, road, and education infrastructure demands are reduced under IPLAN development.

Social Factors

Neo-traditional communities have sidewalks, town squares, front porches, parks, and other public meeting places that encourage socialization. People run errands on bicycle or on foot, thus increasing interaction with other members of their community.

The green approach also provides a variety of housing, including apartments, townhomes, and single family homes, offering choices for all income brackets. This is beneficial for the buyer who has the opportunity to be part of a more-refined development and for the seller, who opens the door for more potential buyers. Some have criticized that neo-traditional developments have a tendency to become enclaves for the wealthy (Millman, 1994). However, this is primarily a short-lived response to the high demand for such communities. As these communities become more common, they will also become more affordable.

Table 2.
Impact differences between IPLAN vs. TREND from 1990- 2010 (1992 dollars where applicable)

Category/Units	TREND	IPLAN	Diff	%
Population Growth (persons)	520,000	520,000	0	0
Employment Growth (employees)	654,000	654,000	0	0
Land Consumption (acres)	292,000	165,000	+127,000	43.5
Number of Housing Units	430,447	431,105	-658	0.15
Water ($ millions)	$634	$573	+$61	9.6
Sewer ($ millions)	$6,790	$6,411	+$379	5.6
Roads ($ millions)	$2,924	$2,185	+$739	25.2
Education ($ millions)	$5,296	$5,115	+$181	3.4
Total Capital Cost of Water, Sewer, Roads, and Schools ($ millions)	$15,644	$14,284	+$1,360	8.7

Adapted from Cost of Providing Government Services to Alternative Residential Patterns, May 1993, Chesapeake Bay Program.

Government Obstacles

In Subdivide and Conquer, Concrete, Condos, and the Second Conquest of the American West (1996), Jeff Gersh asserts that "Sprawl is not the result of free-market choices" (Gersh, 1996). He goes on to explain that, since World War II, low-density has dominated American residential development, institutionalized, in part, by government subsidies and investments. For example, Gersh notes that the public treasury pays for highway extensions, new interchanges, and roads; the government guarantees mortgages for single-family housing, but not for multi-family or mixed-use development; the government also pays farmers not to raise crops in some cases priming land for development; and more. Gersh argues that low-density development is at least partly driven by government subsidies that counter high-density, compact development typical of green approaches.

At the state and local level, zoning ordinances often preclude green approaches. For example, North Carolina state law does not require stormwater management on properties where impervious surface accounts for 30 percent or less of the land area being developed (Milliken, 1996). This has resulted in large lot subdivisions. The goal behind such legislation is to minimize impervious surface, but the result is the need for more roads that often make up for any savings realized. Such forces favoring low-density development are costly for green developers to overcome. The time an alternative design developer spends lobbying his case among local planning officials can more than offset the economic gain from developing the design. This is another cost that will likely be borne by the groundbreakers that, over time, will likely pass.

Financing

Because higher density, green development designs house enough people to make mass transit feasible, families that buy homes in these neighborhoods may be able to forgo the purchase of a second car ("Living," 1993). By reducing transportation costs, families can afford to devote a larger percentage of their income toward a home mortgage. Thus, high-density designs translate into the opportunity to own a home similar in quality, but lower in cost to finance as compared to residences in low- density neighborhoods.

Unfortunately, there is a downside to financing green development. A major stumbling block is that the banks and insurance companies that lend developers money tend to specialize in one-of-a- kind projects ("Neighborhoods Reborn," 1996). If a proposed development doesn't fit the standard pattern, it can be difficult to finance it. This is likely to become less burdensome over time, as green development approaches become more common.

Market Response/Property Values

Robert Engstrom, president of Robert Engstrom Companies, a Minneapolis-based planning and development firm voices the question near and dear to those who are skeptical of green development approaches: "Neo-traditional planning has great intentions, but I'm concerned that the market just will not be there to support it" (Bookout, 1992). As told in basic economic theory, one thing is certain if green development is to have a chance, it has to be in demand.

A 1996 national homebuyer's survey showed that, by a margin of 4 to 1, home buyers are in fact attracted to some of the design concepts of neo-traditional development, but they are not willing to give up cul-de-sacs, big yards and privacy, and other more traditional design benefits (Harney, n.d.). Other national surveys tend to have similar results. However, these findings contradict with observations at the project level. For example, Theresa Brinker, president of TABCO land development company has observed an overwhelmingly positive response. Located in Prince George's County, Maryland, Brinker's Somerset incorporates on- site stormwater treatment systems, known as "Rain Gardens." As Brinker observes, "Sales are above average for that general market corridor. Buyers perceive the gardens as an added value to their home" (Maryland Developer, 1995).

Similarly, in Yardley, Pennsylvania, strategic placement of clustered homes around open space helped sales in Farmview. Farmview earned distinction as the fastest-selling development in its price range in Bucks County (Arendt, 1993). In fact, demand was so high that two developers who had been skeptical of such a design have since filed applications for similar subdivisions. The story reads the same for other developers who have maximized their gain by planning development around environmental features such as open space. A 1995 EPA report, Economic Benefits of Runoff Controls, summarizes the economic benefits of designing developments around runoff management controls, such as ponds and wetlands. Aesthetically landscaped runoff controls can increase property values as much as 50 percent by appealing to buyers interested in hiking around wetlands and lakes, boating, bird-watching, and more. Table 3 summarizes many cases in which both residential and commercial property values increased as a result of runoff controls.

Corporate real estate executives say quality of life is a very important factor when deciding where to locate a new factory or office. Recreational opportunities provided by greenways or open space are an important part of the quality of life that firms and workers seek (National Park Service, 1992). This translates into increased property values and an increased tax base for state and local governments.

Environmental Benefits and Avoided Costs

Pollution Control

Some of the most significant benefits and avoided costs associated with green development approaches can be gained by the environment. For example, the compact, mixed-use design common in green development patterns mean less travel by car and significant savings in automobile emissions. This reduction in automobile emissions, combined with a reduced energy requirement for heating in high-density communities can reduce air pollution by 45 percent (Real Estate Research Corp., 1974). In addition, water consumed by watering lawns is reduced by 35 percent under green development schemes (Real Estate Research Corp., 1974).

Table 3.
Examples of real estate premiums charged for property fronting urban runoff controls

Location	Base Costs of Lots/Homes	Estimated Water Premium
Chancery on the Lake, Alexandria, Virginia	Condominium: $129,990 - $139,990	Up to $7,500
Centex Homes at Barkley, Fairfax, Virginia	Home with lot: $330,000 - $368,000	Up to $10,000
Townhomes at Lake Barton, Burke, Virginia	Townhome with lot: $130,000 - $160,000	Up to $10,000
Lake of the Woods,Orange County, Virginia	Varies	Up to $49,000
Dodson Homes, Layton, Fauquier County, Virginia	Home with lot: $289,000 - $305,000	Up to $10,000
Ashburn Village, Loudoun County, Virginia	Varies	$7,500 - $10,000
Weston Development, Broward County, Florida	Home with lot: $110,000 - $1,000,000	$6,000 - $60,000 depending on lake size, location, and the percent of lakefront property in the neighborhood.
Silver Lakes Development, Broward County, Florida	Varies	$200 - $400 per linear foot of waterfront, depending on lake size and view
Highland Parks, Hybernia, Illinois	Waterfront lot: $299,900 - $374,900	$30,000 -$37,500
Waterside Apartments, Reston, Virginia	Apartment Rental	Up to $10/month
Village Lake Apartments, Waldorf, Maryland	Apartment Rental	$5 - $10/month depending on apartment floor plan
Lake Arbors Towers, Mitchellville, Maryland	Apartment Rental	$10/month
Marymount at Laurel Lakes Apartments, Laurel Lakes, Maryland	Apartment Rental	$10/month
Lynne Lake Arms, St. Petersburg, Florida	Apartment Rental: $336 - $566/month	$5 - $35/month depending on lake size
Sale Lake, Boulder, Colorado	Waterfront lot: $134,000	Up to $35,000
The Landing, Wichita, Kansas	Waterfront lot: $35,000 - $40,000	Up to $20,000
Fairfax County, Virginia	Commercial Office Space Rental	Up to $1/square foot
Laurel Lakes Executive Park, Laurel, Maryland	Commercial OfficeSpace Rental	$1 - $1.50/square foot

Adapted from Economic Benefits of Runoff Controls, September 1995 EPA's Office of Wetlands, Oceans, and Watersheds, Washington, DC.

In the Fall of 1995, the Charleston Harbor Project, funded by the National Oceanic and Atmospheric Administration, and administered by the South Carolina Department of Health and Environmental Control, began a study that compared the water quality impacts of low-density, sprawl as opposed to high- density, traditional town development ("Sprawl versus," 1996). Traditional towns are compact, mixed-use, pedestrian-oriented developments typical of green development patterns.

The design team produced mock developments in both sprawl and traditional town patterns for Belle Hall, a 583-acre site in Mt. Pleasant bordered by the Mark Clark Expressway and the Wando River. As the model developments took shape, comparisons could be made between the two design patterns. For instance, the land area consumed by the traditional town scenario was one order of magnitude less than the sprawl scenario. In addition, while the sprawl scenario provided 30 acres of open space, the traditional town scenario provided 400 acres of open space and greens.

Dr. Elizabeth Blood, of the Jones Ecological Research Center in Newton, Georgia, then analyzed the runoff implications of the two development options. She and her team of graduate students used a computer model based on a modification of the Universal Soil Loss Equation to compare the two designs. Their study found that the traditional town scenario performed better than the sprawl scenario across the board. The volume of runoff from sprawl was 43 percent higher than that from the traditional town. In addition, nitrogen and phosphorus loadings, as well as chemical oxygen demand were higher in sprawl.

Because the study did not include reductions in the amount of lawn fertilizers and motor vehicle use in the traditional town scenario, these results are likely to fall even more in favor of the town design. These results are significant because they reveal the ability of green development approaches to avoid the costs associated with water pollution. At the same time, these approaches also provide aesthetic and habitat benefits associated with increased amounts of open space.

At a more discrete level, green development BMPs also prove to be cost-effective approaches to improving and protecting water quality. Maine's Casco Bay Estuary Project studied the cost- effectiveness of several BMPs used to protect the state's water quality, concluding:

 

• The BMP cost was low compared to the costs of conventional construction practices;

• The BMP cost was small when compared to the overall project cost; and

• The BMP provided additional aesthetic benefits that cannot easily be assigned a dollar value (Casco Bay Estuary Project, 1995).

The Casco Bay report compares green development BMPs to conventional construction practices on a case-by-case basis. For example, there were two options to combating concentrated runoff from carrying soil and phosphorus into Taylor Pond. One was providing additional pipe drainage, the other, construction of a level lip spreader and vegetated buffer. As Figure 3 shows, the level green BMP spreader option was $12 more, but provided the additional benefits of improved water quality, passive recreation, and aesthetics. Based on these benefits, the lip spreader and buffer were installed at Taylor Pond. Of the benefits of this decision, resident Anne Stocker proclaimed, "I love the idea that it [the level lip spreader and wildflower buffer] is low maintenance and property enhancing, since wildflowers don't have to be mowed" (Casco Bay Estuary Project, 1995).

Figure 3. Cost comparison between a traditional and a green approach at Taylor Pond.

[forthcoming]

Adapted from BMPs: Cost-Effective Solutions to Protect Maine's Water Quality, July 1995, the Casco Bay Estuary Project.

In another case cited by the Casco Bay report, the owners of a year-round residence on China Lake wanted to build an addition towards the shoreline. Because the addition of impervious surface could increase phosphorus loadings to the lake, the residents compared two measures that would protect water quality: 1) extension of gutter, a traditional construction practice and 2) an infiltration trench combined with a wildflower buffer, a green approach. A cost comparison between the two options, depicted in Figure 4, showed the trench and buffer to be $50 less (Casco Bay Estuary Project, 1995). Not only was this option more cost effective, but it removed the burden of maintaining gutters that an extension would have required, while providing the aesthetic benefits associated with the wildflower buffer.

Figure 4. Cost comparison of a green BMP and its alternative for protecting China Lake.

[forthcoming]



Adapted from BMPs: Cost-Effective Solutions to Protect Maine's Water Quality, July 1995, the Casco Bay Estuary Project.

Green development that incorporates open space can provide critical flood control during peak flow events and can protect surface and ground water resources by filtering trash, debris, and chemical pollutants before they can enter the water system. The capacity of open space to absorb stormwater and provide natural drainage means that a preserved system of natural streams, or greenway, can substitute for or supplement extended sewer systems (Neighborhood Open Space, 1987).

Studies made in cooperation with electric utility companies show that when the costs of planting, watering, and maintaining trees are considered, tree planting is a more cost-effective energy conservation and carbon dioxide reduction strategy than many other conservation measures. A Chicago study found that in one day 120 acres of canopy cover can absorb up to 5.5 pounds of carbon monoxide, 127 pounds of sulfur dioxide, 24 pounds of nitrogen dioxide and 170 pounds of particulates. Trees in a 525- acre area of Lincoln Park had an annual air pollution mitigation value equivalent to $25,000 of conventional air pollution controls (Nowak and McPherson, 1993). In addition, trees function in the noise pollution reduction process by modifying humidity and climate, by absorbing sound, and by deflection and refraction (USEPA, 1995).

Hazard Mitigation

Use of environmentally sensitive areas for open space can reduce potential property damage costs and loss of life. Hazards that can be mitigated through green conservation of open space include flooding, slope instability, structural fire damage, and earthquake losses. This translates into significant annual savings to the public.

In Summary

Green development approaches have the potential to improve quality of life, increase property values, expand local businesses, encourage alternative transportation, reduce costs to the developer, reduce costs to the public, and more. Although nonmonetary values of alternative green development approaches continue to be the fundamental emphasis of conservation efforts, clear communication of potential economic benefits will help decision-makers to recognize innovative development as vital to the well-being of a community.

There is a need for further study of the costs and benefits of green development. It is necessary to compare green versus traditional development of the exact same parcel of land in order to obtain meaningful results. There is also a need to promote existing inentives to developers and financers to implement green development approaches.

Green Development Literature Search: Summary and Benefits Associated with Alternative Development Approaches. Presented to the U.S. Environmental Protection Agency, Office of Wetlands, Oceans, and Watersheds; Rod Frederick, Work Assignment Manager; in conjunction with Oceans and Coastal Protection Division; Margherita Pryor, Jessica Cogan; September 30, 1996; Prepared by--Tetra Tech, Inc., 10306 Eaton Place, Suite 340, Fairfax, VA 22030; Under EPA Contract #68-C3-0303; Work Assignment #3-112

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