Chicago Wilderness Green Infrastructure Vision

Download:  the Final Report and the full Green Infrastructure Vision map.  This project provides a visionary, regional-scale map of the Chicago Wilderness region that reflects both existing green infrastructure -- forest preserve holdings, natural area sites, streams, wetlands, prairies, and woodlands – as well as opportunities for expansion, restoration, and connection. The broader goal of this effort is to bring the Chicago Wilderness Biodiversity Recovery Plan to life in a more meaningful, visual, and accessible way. This project has developed a map that is, in a sense, a visual interpretation of the Biodiversity Recovery Plan's broad recommendations for protection, preservation, and restoration at a macro scale.

For the purposes of this project, green infrastructure is: The interconnected network of land and water that supports biodiversity and provides habitat for diverse communities of native flora and fauna at the regional scale. It includes large complexes of remnant woodlands, savannas, prairies, wetlands, lakes, stream corridors and other natural communities that have been identified in the Biodiversity Recovery Plan. Green infrastructure may also include areas adjacent to and connecting these remnant natural communities that provide both buffers and opportunities for ecosystem restoration.

The principal objective of mapping recommended regional-scale “resource protection areas” is to draw more focused attention to the biodiversity needs and opportunities of Chicago Wilderness. While clearly not intended to be precise plans for protection or restoration areas, the mapping of large resource protection areas can stimulate the many ongoing local efforts at the community and watershed scale by offering the implicit support of the CW coalition for regional and local conservation actions.

The three principal tasks and objectives of this project are:

  • A multi-state, Chicago Wilderness regional map that identifies on-the-ground, regional-scale opportunities for biodiversity protection and restoration. These opportunities are mapped as recommended “resource protection areas.”
  • The identification of specific protection techniques for each resource protection area, including: acquisition, conservation easements, restoration, greenway connection, and conservation development.
  • The identification of simple guidelines for conservation development, recognizing that urban/suburban development inevitably will occur in or adjacent to many of the recommended resource protection areas.

This plan recommends that a high priority be given to identifying and preserving important but unprotected natural communities, especially those threatened by development, and to protecting areas that can function as large blocks of natural habitat though restoration and management. More specifically, the plan recommends the:

  • Creation of large preserves,
  • Creation of community mosaics,
  • Protection of priority areas, especially remaining high-quality sites,
  • Protection of any large sites with some remnant communities, and
  • Protection of land that connects or expands existing natural areas.

The plan recommends that these areas be preserved where possible by the expansion of public preserves, by the public acquisition of large new sites, or by the actions of private land owners. Much of the focus of the resource protection area identification proposed in this project is tied to sensitive watersheds and stream-based greenway linkages.

The Biodiversity Recovery Plan contains an extensive focus on the need to involve local governments and regional policy makers in the preservation, management, and restoration of land and water resources. The Biodiversity Recovery Plan also contains the following objectives for local governments: inventory sensitive habitats and identify opportunities for open space preservation and restoration; modify comprehensive plans, ordinances, and engineering practices to consider the impacts of development on biodiversity; incorporate provisions for biodiversity protection and restoration in the design plans for new development and redevelopment.

In total, over 1.9 million acres of recommended resource protection area were identified and mapped within the “Chicago Wilderness” assessment area. It is notable that more than 545,000 acres of protected “natural” public open space already exist within this region. 

For each of the identified resource protection areas, workshop participants identified and recorded recommended conservation approaches. Recommended approaches addressed opportunities for acquisition, conservation easements, greenway connections, and restoration. Workshop participants also made recommendations about appropriate development within resource protection areas, ranging from no new development to limited conservation development.

Conservation Development Recommendations: Recommendations also were developed for conservation development for how projected development and redevelopment should be planned and designed to maximize preservation and restoration of biodiversity. It was observed that traditional land development approaches have generally ignored the natural functions of the landscape. In particular, development activities have fragmented ecosystems, disrupted natural hydrologic patterns, introduced invasive plant and animal species, and eliminated fire from the landscape. The consequences are striking. Illinois has lost roughly 90 percent of its wetlands and over 99.9 percent of its tallgrass prairie ecosystems. In northeastern Illinois, over 40 percent of the stream and river miles have been channelized and almost none of our urban/suburban rivers support healthy, diverse fish communities. Average annual flood damages total about $40 million. And new development threatens our surface and groundwater supplies. In response, new and evolving development standards and ordinances promise to reduce additional adverse impacts. But with about 2 million new residents forecast in northeastern Illinois alone, our already degraded natural environment will continue to suffer.

In order to be truly sustainable, development must not only protect beneficial environmental functions but must improve systems degraded by past disturbances. Not only does the technology exist to achieve this objective, but sustainable development approaches cost no more than conventional approaches. Further, sustainable development will reduce long term maintenance costs, enhance property values, and improve the quality of life in our communities. Goal: All development shall protect and improve the natural environment.

Development Principles:

  • Minimize the total consumption of land, particularly the creation of impervious surfaces, by new development.
  • Utilize existing infrastructure by maximizing infill and redevelopment.
  • Maintain and reestablish functional natural systems: soils, plants, water.
  • Minimize disturbance of soil structure and topography.
  • Develop landscapes sustainably, utilizing a diversity of native plant species.
  • Manage precipitation as a resource close to where it falls, not as a disposable waste product.
  • Utilize the landscape to naturally filter and infiltrate runoff before it leaves the development site.
  • Eliminate adverse off- site and downstream effects of runoff and wastewater.
  • Maximize, interconnect, and restore natural open space.
  • Maximize opportunities for local access to open space.
  • Establish administrative and financial mechanisms for the long-termmanagement of the natural elements of developed sites.
  • Assess cost-effectiveness of sustainable designs based on their long-term, life cycle costs.

Recommended techniques and approaches:

Conservation development

  • Preserve natural topography, land forms, and views.
  • Avoid sensitive natural areas and hydrologic features, including seeps, springs, and organic/hydric soils when locating new developments and roads.
  • Utilize site designs that minimize the amount of impervious surface area.
  • Cluster residential development to minimize land disturbance and maximizenatural open space.
  • Make roadway widths no wider than necessary to ensure public safety and to accommodate other modes of travel such as bicycling.

Natural drainage

  • Utilize natural drainage as an alternative to storm sewers.
  • Use vegetated swales, filter strips, and perforated underdrains to maximize runoff filtering and infiltration.
  • Daylight storm sewers by converting them to open swales.
  • Eliminate paved/sewered hydraulic connections, wherever feasible.

Stormwater detention

  • Require stormwater detention that effectively controls the full range of flood events.
  • Design detention areas to minimize downstream flow variability for two-year storms.
  • Design detention to maximize removal and transformation of runoff pollutants.

Natural landscaping

  • Use native plants as a preferred alternative to the default turf grass landscape.
  • Emphasize the use of deep-rooted native vegetation on the banks of streams and detention ponds and other areas that are susceptible to erosion.
  • Buffer strips and greenways along streams, lakes, and wetlands.
  • Avoid development in riparian areas, particularly avoiding environmental features such wetlands, steep slopes, the 100- year floodplain, and wildlife corridors.
  • Protect or restore native vegetation in riparian buffers. Buffer widths may vary but the minimum average width should be fifty feet from the edge of the aquatic resource (e.g., wetland or stream), expanding to at least 100 feet for high quality aquatic resources.
  • Multiple-use riparian greenways should be established, following the recommendations of the Northeastern Illinois Regional Greenways Plan, accommodating trails and wildlife corridors wherever feasible.
  • Retain and/or restore emergent and near-shore vegetation at stream and lake edges.
  • Restore streamside wetlands.

Soil erosion control

  • Develop and implement best management practices to control soil erosion and sedimentation during construction.

Sustainable wastewater management

  • Utilize alternatives to new and expanded effluent discharges to high-quality streams --e.g., route sewage flows to regional facilities or use land treatment.
  • Utilize effluent polishing, through constructed wetlands or land application, for all discharges to moderate- and high-quality streams.
  • Utilize treated effluent for irrigation and/or grey water uses as an alternative to direct discharge to surface waterbodies.

Other

  • Develop programs to minimize use of pesticides and fertilizers on municipal lands through Integrated Pest Management policies or other means.

Mechanisms to achieve recommendations:

Designation of lands with conservation easements or dedication to local government at the preliminary planning stage.  The context for applying sustainable development principles is critical to the achievement of the goals of the green infrastructure vision. Three general situations are addressed.

Development within recommended resource protection areas: For each identified resource protection area, specific recommendations were made regarding whether and how development should be accommodated. Where conservation development is the recommendation, the principles and techniques outlined above should be implemented to their fullest extent. In particular, development should be designed and tailored to the specific natural resource characteristics of the identified resource protection area. For example, if the resource protection area contains fens or other groundwater-fed aquatic ecosystems, particular emphasis needs to be placed on assuring the protection of pre-development groundwater quantity and quality conditions. A general recommendation for conservation development within resource protection areas is to limit development intensities, particularly impervious surfaces (like parking lots) or structures that would disturb sensitive habitats. Similarly, all attempts should be made to fully preserve all significant remnants of native vegetation (e.g., by creative site designs and clustering) and to provide natural landscaping buffers adjacent to remnant or restored natural habitats. Finally, it is essential that conservation designs include long-range plans for ecosystem management, including both financial arrangements and protective legal structures such as conservation easements.

Development within watersheds of high quality streams or lakes: The Biodiversity Recovery Plan, Chapter 6, identifies priority watershed of major stream and river systems based on the presence high aquatic biological diversity and/or species or features of concern. However, this prioritization was done for just northeastern Illinois. Nonetheless, it is critical that development in the watershed of any high quality or biologically sensitive stream or lake be done following stringent conservation development principles. Information on sensitive aquatic systems in Wisconsin and Indiana can be obtained from Wisconsin DNR and Indiana DNR and/or Department of Environmental Management. While all of the listed conservation development principles and techniques are important, several should be emphasized in the protection of high quality aquatic systems. For example, site design and stormwater management must be done in a manner that maximizes both natural recharge of rainfall and runoff and effective filtering of runoff pollutants. Construction site soil erosion and sediment control also are critical.

Sustainable, alternative wastewater planning and treatment/discharge approaches are essential to protecting high quality systems. And protection/restoration of extensive naturally vegetated buffers along the periphery of stream, lake, and wetland edges – at least 100 feet on all sides – is critical.

All other development: Throughout the broader Chicago Wilderness region, in urban, suburban, and rural edge settings, there are strong arguments for conservation development. Beyond the obvious biodiversity conservation benefits, conservation development approaches generally cost considerably less than conventional design, enhance property values and quality of life, help protect groundwater aquifers, and reduce problems and costs associated with flooding and water quality degradation. Depending on the intended land use and site characteristics and constraints, appropriate elements of conservation design can and should be selectively tailored to each individual property