GREEN INFRASTRUCTURE DESIGNS SCALABLE SOLUTIONS TO LOCAL CHALLENGES UPDATE SEPTEMBER 2017 ABOUT DELTA INSTITUTE Founded in 1998, Delta Institute is a Chicago-based nonprofit organization working to build a more resilient environment and economy through sustainable solutions. Visit online at www.delta-institute.org. This publication was originally released in July 2015 with support from the National Oceanic and Atmospheric Administration through the Illinois Department of Natural Resources (IDNR, CFDA Number 11.419). The September 2017 update adds two new green infrastructure designs to the toolkit. Delta thanks Tim King PE, LEED AP BD+C and Luke Leising, AIA, PE, LEED AP O+M of Guidon Design for their work designing the initial five templates. Guidon Design, Inc. is a multi-disciplinary architecture and engineering firm. Delta also acknowledges the work of graduate students Loren Ayala and Liliana Hernandez-Gonzalez, civil and environmental engineering students at Northwestern University and Kimberly Grey, Chair of Chair of Civil & Environmental Engineering at Northwestern in developing the box tree filter and green roof designs. Additionally, Delta acknowledges Claire Costello, an undergraduate student at University of Chicago for her assistance reviewing, editing and preparing additional components for publication. Additionally, we are grateful to the following Calumet region communities for their contributions and review of the toolkit: Jodi Prout, City of Blue Island Jason Berry, City of Blue Island Dawn Haley, Village of Riverdale Mary Ryan, Village of Calumet Park Bryan Swanson, City of Calumet City Stan Urban, Village of Dolton Hildy Kingma, Village of Park Forest Ernestine Beck-Fulgham, Village of Robbins Finally, Delta Institute thanks Josh Ellis of the Metropolitan Planning Council, and the Calumet Stormwater Collaborative for their support of the project. 2 TABLE OF CONTENTS 1| Introduction ..............................................................................4 2| Stormwater Management .......................................................7 3| Green Infrastructure ................................................................8 4| Decision Support Tool ............................................................12 5| Bioswale/Hybrid Ditch ...........................................................14 6| Rain Garden ............................................................................23 7| Stormwater Planters ..............................................................30 8| Permeable Pavement .............................................................43 9| Underground Storage ............................................................49 10| Box Tree Filter .......................................................................55 11| Green Roof ............................................................................62 Appendix A: EPA Brownfields Decision Flow Chart .......................................69 Appendix B: Illinois Urban Manual..............................................71 Appendix C: Engineered Soil Specification ...............................87 Appendix D: Resources ..............................................................90 3 1| INTRODUCTION Introduction a wide geography, but they are particularly well- Many municipalities struggle to effectively address suited to the Midwestern climate. stormwater and flooding issues that impact their Why Green Infrastructure? communities, and they are increasingly interested To avoid flooding, precipitation must be redirected in green infrastructure as tool for stormwater from impermeable surfaces, which is often management. However, these municipalities often achieved using a "gray infrastructure" approach face barriers to green infrastructure installation, which uses gutters and underground pipe networks such as the lack of capacity and technical that discharge to local sewers or water bodies. expertise for implementation; these barriers can Green infrastructure is a valuable supplemental tool be particularly significant for municipalities with to alleviate stormwater overflow, and it uses natural constrained human and financial resources. conditions to slow the movement of water, helping To help municipal managers and decision-makers to manage the flow of stormwater and mitigate begin the process of exploring and implementing flooding issues. green infrastructure, Delta Institute (Delta), created Green infrastructure can also deliver a variety this practical toolkit which features scalable tools of co-benefits to the surrounding community. and design templates. For example, rocks and soil can help stormwater The target audience for this toolkit includes infiltrate the soil, and plants can purify the water public sector managers, planners, and decision- by storing contaminants in their root systems. makers, particularly those at the municipal level. Additionally, green infrastructure can mitigate flooding while also helping to alleviate stress on This toolkit aims to provide users with a clearer aging gray infrastructure systems. See Table 1 understanding of how to identify opportunities for on the following page for more co-benefts of the green infrastructure implementation, which green included designs. infrastructure treatments are most suitable for a specific site or purpose, and how to make informed Green infrastructure can also support community decisions based on reasonable cost estimates. planning objectives and provide additional benefits. These tools are designed to be broadly applicable These benefits include more aesthetically pleasing to a variety of sites and decision-makers, but uses of blighted parcels or brownfields, which can they maintain a focus on addressing the issues create economic development opportunities while and constraints that are specific to resource- providing habitat or recreational improvements. constrained municipal managers and decision- Overall green infrastructure installations can makers. All of the green infrastructure treatments enhance neighborhood vitality and increase included in this toolkit can be scaled to sites across property values. 4 Table 1: Shared and unique benefits of the seven green infrastructure applications included in this toolkit. Stormwater Bioswale/ Permeable Underground Rain Garden Box Tree Filter Green Roof Planter Hybrid Ditch Pavement Storage Pests Green infrastructure in any format reduces standing water, eliminating breeding grounds for mosquitoes Urban Heat Retaining water in the soil lowers surface temperatures, reducing the urban heat island effect. Island Effect Water entering existing stormwater infrastructure is cleaner, with substances removed by physical and biological Water Qiuality means. Plants can absorb and process harmful compounds through phytoremediation and use carbon Air Quality dioxide during photosynthesis. The introduction of green spaces into urban environments create a habitat for wildlife, Grey Spaces improve quality of life, and are aesthetically pleasing. Longevity Green roofs on average last longer than grey roofs. Food Production Green roofs create a space for urban agriculture. Noise The additional insulation from green roofs block noise pollution. Energy Costs Green roofs act as an insulating layer that retain heat and cold, reducing energy bills. Winter Weather Materials used in permeable pavements better retain heat and require less salt during winter. 5 This page has been intentionally left blank. 6 2| STORMWATER MANAGEMENT Overview to the point where it falls. This allows for the natural Stormwater management is paramount to the processes of infiltration and evapotranspiration design and function of any human development. to occur and minimizes stormwater runoff. There The natural water cycle allows for the infiltration are multiple ways that this can be integrated into of stormwater into the ground and for the the design of the urban fabric. For example, a absorption of water by plant roots and leaves strategically placed planting bed can function as (evapotranspiration). Impervious surfaces a pocket storage area for rainwater. This allows from pavement and buildings fulfill our need for rainwater to infiltrate directly into the ground shelter and commerce, but they also eliminate water table and allows for uptake into plants, or opportunities for infiltration and natural plant it slowly redirects runoff elsewhere. The green processes. This causes more rainfall to flow from infrastructure approach mitigates flooding of impervious surfaces, and the increased rainfall receiving waters and aging infrastructure which runoff causes flooding and accelerates erosion. gets overwhelmed with urban runoff during even Rainfall runoff also collects pollutants as it flows moderate storms. over impervious surfaces, causing increased water Municipalities face a growing need for effective quality issues. stormwater management because of localized Gray vs. Green Infrastructure flooding due to inadequate gray infrastructure When rain falls on an impervious surface, it must be and more extreme weather events caused by redirected to avoid flooding of streets and buildings. climate change. Stormwater quality regulations The traditional approach to redirecting runoff are also becoming increasingly more and more has been to remove it from the area as quickly as stringent. Green infrastructure is a method of possible. Embedded below the street system is an handling stormwater that can be cost-effective underground network of pipes and structures