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About EcoPlanIT Madison

Introduction And Project Overview

Ecological Inventory - Literature Review - Analysis - Recommendations & Conclusion

Each spring semester at the University of Wisconsin-Madison, a team of graduate students in the Department of Urban and Regional Planning collaborate on a project that addresses a planning issue of local or regional concern. This year’s team set out to formulate an ecological sustainability plan for the City of Madison focusing on strategies to improve land use practices.

While acknowledging that ecological sustainability is a work in progress, an ideal whose full realization remains uncertain, and a concept whose nuances will be subject to further revisions and debates, we believe it can provide motivation and guidance in creating city plans and envisioning communities of the future. With the world’s population becoming more urban and the ecological impacts of human beings more widespread, protecting the environment is not simply a matter of far flung wilderness areas. It is an issue that must also be addressed through the design and structure of the human-built environment. Furthermore, adopting ecological sustainability as a core planning principle can contribute to the creation of safe, healthy, and inspiring places to live. Our project, therefore, is based on the conviction that ecological health and sustainability are intimately connected to the quality of human life in cities.

The analysis and recommendations presented in this project report are intended to provide input to the comprehensive planning process already underway in Madison. As a starting point, we adopted four ecological-related goals identified by the City as a framework for sustainability:

The four items in this list translate the somewhat abstract principle of ecological sustainability into specific, concrete goals. In formulating a plan to help Madison achieve these goals, we structured our work around four main components: an inventory of Madison’s ecological attributes; a review of technical literature and existing plans that address ecological sustainability; a quantitative, spatial analysis of Madison’s current land use, including an evaluation of Madison’s current ecological performance; and a set of recommendations organized by district within the City. The paragraphs that follow provide an overview of these components and describe the methodology used in conducting our analysis and developing our recommendations. Links in the text will direct you to the relevant pages on this web site with more detailed information.

Ecological Inventory

The purpose of the inventory is to provide a foundation for understanding the many physical attributes of Madison that play a significant environmental role and to compile information that could be useful to the subsequent analysis. It is organized into six sections: history, air, water, land, ecologically-significant areas, and cultural resources.

Ecological Inventory

The history section provides a chronological overview of Madison’s environmental history, following the City’s growth and development from prehistoric times and early settlements to the present day. This historical perspective can be useful in understanding environmental problems encountered in the past and how the City managed them. The section on ecologically-significant areas begins by describing the regional ecological context to which Madison belongs. It then discusses Madison’s conservation parks, environmental corridors, and lakes—the spaces within the City that continue to provide viable habitat for wildlife. The land resources inventory gives special attention to soil and land cover types in Madison. It describes how the City enjoys both an abundance of soil suitable for agriculture and land suitable for urban development. The water resources section discusses the City’s lakes, streams, wetlands and groundwater, which are integral to life in Madison but highly sensitive to human impacts. The air quality section provides information on sources of pollution within Madison and highlights the concern of increasing traffic congestion and ground level ozone concentrations. Finally, the cultural resources inventory discusses aspects of the human-built environment including City parks, street networks, and historical districts.

Literature Review

After compiling the inventory on Madison’s ecological attributes, we consulted technical literature and existing plans of other cities to see what sustainability strategies are being discussed and implemented. This literature review is divided into five sections: ecosystems services, climate change, urban agriculture, stormwater management, and interjurisdictional issues. The objective of this research was to understand more thoroughly the significance of the environmental issues behind each of our four sustainability goals and to gather information and ideas that could potentially contribute to achieving those goals. Most of the performance standards we used in our analysis to represent urban best practices were derived from this literature review.

Literature Review

Analysis

The analysis component of this project consisted of three basic parts. First, we established performance standards corresponding to seven different land use attributes. These attributes provide the measurable variables used to evaluate Madison’s current ecological performance and to identify areas for improvement in meeting the four goals. Second, we conducted a detailed examination of Madison’s current land use, using a geographic information system (GIS) database. This analysis produced quantitative measurements of the quantity or spatial extent of the seven key attributes. The results were then compared to the best practice standards. Third, we conducted a survey of neighborhood groups and plans throughout the City to see what ecology-related goals and strategies have already been adopted in Madison. These three components, as well as strategies proposed in the technical literature and other city plans we reviewed, all informed our final recommendations.

Identification of Performance Standards for Land Use Attributes

The four goals guiding this project provide an essential framework for applying the principle of ecological sustainability to city planning. But in order to develop practical, land use strategies to meet these goals, it is important to establish criteria or metrics with which to evaluate the current ecological status of the City’s neighborhoods and identify specific objectives for improvement. For example, impervious coverage (including surfaces such as street paving and rooftops) is a land use attribute strongly linked to the quality and volume of stormwater runoff. The proportion of impervious coverage in a city’s total surface area can be measured and used as an indicator of the environmental impacts of stormwater. From our inventory and literature review research we established the following set of attributes to analyze in detail:

Although this list is not necessarily definitive or exhaustive, these attributes are particularly relevant to our four sustainability goals. The summary that follows explains how each attribute is related to one or more of the four goals and the performance standards associated with the attribute used to evaluate Madison’s districts. These standards are derived whenever possible from published studies and comprehensive plans, but for the cases in which no standard exists, we developed our own based on our analysis of Madison. More information on the significance of each of the specific goals can be found on the detailed pages for each goal: Green Space - Natural Areas - Climate Change - Stormwater and a summary of the attributes organized according to goal can be found in Table 1.

Open Space

The availability of public open space is an important characteristic of cities that contributes to their aesthetic appeal and provides recreational opportunities for residents (Green Space). Accommodating greater areas for open space produces additional benefits including stormwater infiltration (Stormwater) and the mitigation of climate change (Climate Change). The performance standard for open space was adopted from the National Recreation and Park Association (NRPA) as described in Park, Recreation, Open Space and Greenway Guidelines by James D. Mertes and James R. Hall (1995).

Performance Standard: Ten acres of public open space per 1,000 residents.

Natural Areas

Because of the range of ecological services they provide, natural areas relate to all four sustainability goals. In order to constitute effective habitat for viable wildlife populations (Natural Areas), however, a natural area must be sufficiently large. Research has shown that at least 25 acres of compact forested area are needed to sustain a diversity of bird populations, and at least 250 acres are needed for populations of small to medium-sized mammals. Whether or not it is practical or even feasible for a particular urban area to provide such habitat remains somewhat of a value judgment.

The standards we used, therefore, are derived partly from scientific literature and partly from our own analysis of Madison (described in the next section). Our GIS analysis revealed six 25-acre patches of natural space and at least two additional potential 25-acre sites. With Madison’s population of 208,000, eight 25-acre sites citywide translates into 25 acres per 25,000 residents. The 1,200-acre University of Wisconsin Arboretum is currently the only natural area in Madison that is larger than 250 acres. One additional area encompassing the Cherokee Marsh conservation park and adjacent lands could be expanded to meet this standard as well. A “no net loss” recommendation has also been included in our district level recommendations to protect existing natural areas from development pressures.

Performance Standards:
  1. Eight natural area sites of 25 acres or more on a citywide basis
  2. One additional site exceeding 250 acres
  3. No net loss of existing natural space.

Total Green Space

In combination, patches of open space and natural areas constitute the City’s total green space. While we have not developed a unique performance standard for total green space, we have created a series of maps and charts to illustrate the distribution of all ecologically productive areas throughout the Madison study region.

Community Gardens

Community gardens create opportunities for urban agriculture (Green Space). As with other types of open space, these gardens can also contribute to other goals, such as stormwater reduction (Stormwater). As part of a thriving local food system, community gardens can contribute to energy conservation by cutting energy consumption associated with transportation and storage needs for food distribution. Our standard for community gardens is derived from a citywide standard currently under consideration for inclusion in Madison’s comprehensive plan. Applying it on a district level can ensure that community gardens will be equitably distributed throughout city.

Performance Standard: At least one community garden site per 2,000 residents.

Street Trees

By shading buildings, cooling the air through evapotranspiration, and intercepting rainfall, street trees are important to mitigating the urban heat island effect (Climate Change) and to reducing stormwater runoff (Stormwater). In general, increasing the coverage of urban tree canopy can be a significant part of an effort to promote pedestrian-friendly streets and city neighborhoods that are not overwhelmed by automobile traffic. Because they provide many benefits with few or no negative side effects, we adopted a standard of complete tree canopy cover for Madison’s streets.

Performance Standard: 100 percent street tree coverage in residential neighborhoods.

Impervious Coverage

As described above, research has shown a strong link between impervious coverage and the environmental impacts of stormwater runoff. Aquatic ecosystems can start to experience environmental stress when impervious coverage within a watershed reaches ten percent. Reducing the amount of impervious coverage can reduce quality and volume of runoff that enters surface waters by allowing for greater natural infiltration into the ground (Stormwater). In addition, a reduction in the surface area of street paving and roofing shingle can help mitigate the urban heat island effect and reduce the use of energy-intensive air conditioning in the summer months (Stormwater). In establishing a performance standard, we selected three targets for different levels of city density: high (more than ten residents per acre), medium (five to ten residents per acre), and low (fewer than five residents per acre). This classification is used to recognize that, while one would expect denser areas within a city to have a higher percentage of impervious surface area, higher densities in one part of the city can accommodate impervious coverage reductions in other parts of the city.

Performance Standard: Maximum of 50 percent impervious coverage for high density districts (Isthmus); maximum of 30 percent impervious coverage for medium density districts (Near West); maximum of 20 percent impervious coverage for low density districts (West, South, East, and North).

Residential Sidewalks

Sidewalks and sidewalk connectivity help create pedestrian-friendly neighborhoods that are less dependent upon automobile use for short trips (Climate Change). Adding sidewalks, however, can have some negative side effects; sidewalks increase impervious cover, and installing them on older streets that currently lack them could entail removal of trees and shrubs that have grown up along the road. To allow flexibility in addressing sidewalk deficits, we adopted a performance standard slightly below 100 percent. In addition, our goals for impervious coverage reductions account for any increase in sidewalk paving required to meet the sidewalk performance standard.

Performance Standard: Sidewalks on a minimum of 95 percent of residential streets.

Transit Service

As mass transit is more energy efficient on a per rider basis than auto travel, expanding transit service can provide alternatives to auto use and reduce greenhouse gas and waste heat emissions (Climate Change). Rather than adopt a uniform standard for the City, we established a standard that depends on the population density of each district. Literature on mass transportation has suggested that a density of seven units per acre is needed to support a bus transit system. With population in census blocks used as a proxy for housing units per acre, it became apparent that Madison Metro provides service in areas that are well below the seven-unit density threshold. For our standard, then, we calculated the average density of census blocks currently served by Madison Metro per district and used that as our district minimum.

Performance Standard: All census blocks with a population density equal to or greater than the average population density of census blocks presently served by mass transit should be located within 1/4 mile of a transit stop.

GIS Analysis of Madison’s Current Ecological Performance

Once we had established our set of land use attributes and identified performance standards for each, we set out to analyze and assess Madison’s current performance relative to these standards. (It should be noted, however, that in several cases, the standards were not finalized until after our analysis of Madison, because in instances where no standard could be found in existing literature or city plans, this analysis helped us determine what could be reasonable or feasible.) For purposes of analysis we divided Madison into six districts: West, Near West, South, Isthmus, North, and East. Population data for each district used in calculating our statistics was derived from the 2000 U.S. Census. To be sure, this division is not the only valid way of structuring an analysis Madison’s land use. Whatever division is used, however, should provide some flexibility for the City as a whole in meeting the ecological performance standards while at the same time ensuring that steps taken to achieve those standards will produce benefits distributed throughout the City. For example, meeting the standard of ten acres of public open space per 1,000 residents may do little good if all new open space is added exclusively near the City’s periphery.

For each district, the seven attributes were measured using data from the City of Madison Engineering Division, the Community Action Coalition, the Dane County Land Information Office, and the University’s Land Information and Computer Graphics Facility. With the aid of high-resolution aerial photography and a geographic information system, an ecological land use database was created and analyzed. ArcGIS software was used for this analysis. This section of our overview explains how we measured each of the seven attributes in Madison.

Open Space

In this study open space is defined as non-forested patches of public or private land greater than one and a half acres in size; this size represents a minimum area that could produce significant environmental benefits. Using high-resolution aerial photos of Madison, open space patches were identified visually and digitized manually. The digitized layer was then matched with a land ownership data set provided by the City to determine whether the digitized open space is public or private. From the total area of public open space, we calculated for each district acres of public open space per 1,000 residents.

Natural Areas

Our analysis attempted to measure the size and abundance of Madison’s natural areas, which were defined as forest fragments, water impoundments, and conservation parks. Forest fragments were identified using aerial photography. As with open spaces, only those forested patches of 1.5 acres or greater were mapped. Using data from the City of Madison, they were then divided into two subsets: publicly-owned land and privately-owned land. This distinction is important because land that is publicly owned may be easier to secure for conservation purposes. Water impoundments were defined as inland lakes or ponds exceeding 1.5 acres in size, and they were identified using the aerial photographs and digitized manually. Finally, data on conservation parks was provided by the City’s Parks Department and added to our database.

Community Gardens

Madison currently has 14 community gardens supported by the Community Action Coalition for South Central Wisconsin, Inc. (CAC). Information on the location of these gardens and other private community gardens were obtained from CAC and mapped by address.

Street Trees

We examined the aerial photos to identify street segments with fewer than one tree per approximately 100 feet of linear distance. While many residential yards have trees, our definition of “street tree” was limited to mature trees with canopy extending over public street surfaces and young trees located within ten feet of the roadway and capable of shading street pavement once mature. Street segments without these trees were manually digitized in ArcGIS, and the final statistic was calculated as a percentage of treeless streets in each district.

Impervious Coverage

Impervious coverage was divided into residential and non-residential components. Residential parcels were defined as single family and duplex housing types. We calculated impervious coverage by adding the areas of building “footprints” (the ground surface area occupied by the building), driveways, and sidewalks. Values for the building footprint areas were provided by the City of Madison Engineering Division, and residential driveways and sidewalks were estimated. Driveway areas were estimated by multiplying average driveway width by the distance of the building setback from the road. Similarly, sidewalk areas were estimated by multiplying the width of the lot frontage by the average sidewalk width, which was determined through site surveys. It should be noted that, as residential impervious coverage was not measured directly, our calculations are subject to some degree of error.

Non-residential parcels were defined as commercial, industrial, and multi-family land uses. Non-residential impervious coverage was calculated by adding building footprints, parking lot areas, walkways, and other miscellaneous spaces. Like the residential components, the footprint, parking area, and walkway data were provided by the City of Madison Engineering Division. Sidewalk area estimates were based on a published average for commercial areas and are measured as an additional four percent of impervious area to the total parcel. These estimates are also subject to some degree of error.

Although our goal is to reduce impervious coverage, sidewalks constitute one source of impervious coverage that we are, in fact, recommending. In determining the reductions in impervious coverage needed to meet our standards for this attribute, we adjusted our calculations to compensate for our recommendation of providing sidewalk coverage on 95 percent of residential streets in each district.

Residential Sidewalks

Data for residential parcels with sidewalks was obtained from the City Engineering Division, which compiled this data from site surveys. The number of parcels with sidewalks in each district was then converted into a percentage of residential parcels with sidewalks in each district.

Transit Service

To measure bus service in Madison, we obtained a GIS data layer of Madison Metro bus stops from the City Planning Department. In ArcGIS a 1/4-mile buffer was added around each bus stop in order to show the areas currently served by transit. This information was then combined with population data in order to identify those areas not currently within a 1/4-mile radius of a transit spot but whose census block population density equals or exceeds that of the average density currently served by transit.

Survey of Neighborhood Goals

In addition to evaluating Madison’s ecological performance by comparing the results of our spatial analysis to our adopted standards, we conducted a review of existing neighborhood plans in each district to learn how they are currently addressing issues related to ecological sustainability. In general, we found that neighborhood goals are consistent with our own findings, but that their plans may have not yet identified land use strategies focused on specific parcels within their neighborhood. The introduction page for each district summarizes the results of our review of neighborhood plans and goals.

Recommendations

After completing the analysis component of this project, we began to formulate specific, land use recommendations for each of the six districts of Madison. Having examined the seven attributes in detail and studying the ecological issues most critical to each city area, we considered how improvements relating to these attributes could serve our four main goals. Our recommendations are organized on this web site according to district and further organized by goal.

Conclusion

As the City of Madison prepares its comprehensive plan, it is our hope that this study on land use and ecological sustainability can contribute to the formulation of targeted planning strategies to protect the many environmental resources that are important to the City and to improve the quality of life for the City’s residents. We recognize that this study is only a beginning, and that our methodology entails considerable uncertainty. With time, new research will be completed and more planning initiatives will be implemented that may make it possible to establish standards with greater precision or certainty or to identify other measurable attributes that prove useful in evaluating ecological performance. Nevertheless, this project represents a new way of analyzing land use and its relationship to local ecology. It is a potentially valuable tool for addressing environmental issues through planning both in Madison and elsewhere. Perhaps the first test of this tool’s effectiveness will come when Madison formally adopts a comprehensive plan that includes some of the recommendations we present on this web site and to see if they serve the City well in its search for ecological sustainability.

Table 1: Metrics and Performance Standards by Goal

  Green Space Natural Areas Climate Change Stormwater
What was measured Acres open space in district: total, public, and private Acres natural area in district: Total, Public, and Private Acres of impervious cover in district: Residential and Non-residential % street segments without street trees
  Acres of open space per 1,000 population: Total, Public, and Private Acres natural area per 1,000 population: Total, Public, and Private Acres of impervious cover on public parcels % of Census block population located within a 1/4 mile of bus stop
  % of district area that is open space: Total, Public, and Private % of district area that is natural area: Total, Public, and Private Acres of impervious cover per 1,000 population: Residential and Non-residential % of residential parcels with sidewalks
  Number of community garden sites per 2,000 pop in district Number of natural areas > 25 acres in size, Number of natural areas > 250 acres in size % of district area that is impervious cover: Residential and Non-residential  
Performance Standard 10 acres of public open space per 1,000 population 1 natural area larger than 25 acres for every 25,000 population, or 8 such areas for Madison 20% impervious for East, West, and South districts (low density) 100% of streets with trees
  1 community garden site per 2,000 population 2 natural areas larger than 250 acres 30% impervious for Near West district (medium density) 100% of blocks with threshold density in 1/4 mile of bus stop
      50% impervious for Isthmus district (high density) 95% of residential parcels with sidewalks