Files in this item
application/pdfStormStore Feasibility Study Report_LandHydro.pdf (4MB)
|StormStore feasibility study version, reissued November 2017 with StormStore cover, acknowledgments, and project team information|
|Title:||Land and Hydrologic Analysis for Stormwater Detention and Volume Control Trading Exchange in Cook County, Illinois|
|Author(s):||Allan, Kingsley; Ballerine, Clayton; McGuire, Mary Pat; McConkey, Sally|
|Geographic Coverage:||Cook County|
|Abstract:||Numerous studies have attempted to identify the implications of climate change with respect to hydrologic extremes (e.g., IPCC, 2007; CCSP, 2008; Milly et al., 2008; USGCRP, 2017). These studies project future climate conditions with more frequent extreme precipitation events in many regions around the world, including parts of the United States. The U.S. Global Change Research Program (2017) indicates that “heavy precipitation events in most parts of the United States have increased in both intensity and frequency since 1901 (high confidence).” There are important regional differences in trends, with the largest increases occurring in the northeastern United States (USGCRP, 2017), followed by the Midwest (Karl et al., 2009). USGCRP (2017) also states that “mesoscale convective systems (organized clusters of thunderstorms)–the main mechanism for warm season precipitation in the central part of the United States–have increased in occurrence and precipitation amounts since 1979 (medium confidence).”
Climate model projections also indicate that northeastern Illinois, including the Chicago metropolitan area, will experience more frequent and more intense rainfall events in the future (Markus et al., 2012, 2016). These increases will lead to more intense and more frequent urban flooding events and to increased human, environmental, and economic risks. Thus, various planning and management measures need to be considered by urban communities responsible for administering ordinances governing the construction and maintenance of stormwater management systems and for floodplain management to address public safety concerns, property damage, and economic interruption from intense precipitation.
Future climate projections based on general circulation models (GCM) are typically downscaled to finer temporal and spatial scales using statistical or dynamical downscaling models. However, watershed-scale climate data generated by climate models still do not provide precipitation data in a format useful for community engineers and planners to prepare, mitigate, and adapt to future conditions. In this study, a method is designed to analyze and express climate data in a format that can be readily used to assess future extreme precipitation events in models commonly used for sizing stormwater infrastructure and identifying flooding potential. This report presents a newly designed framework to determine future condition rainfall frequency maps for 24- and 48-hour duration rainfall events and for a range of recurrence intervals (also called return periods). This framework directly supports climate adaptation and mitigation by providing an understandable method for community engineers and planners to demonstrate the impact of climate change at the local level and develop specific adaptation strategies that will reduce future risk.
The primary objective of the land and hydrologic analysis component of the feasibility study is to identify and quantify opportunity areas with favorable characteristics for stormwater detention or volume control. The analyses were performed on a geospatial platform, building on Geographic Information System (GIS) tools. Opportunity areas could be used to provide trading credit when a development cannot meet the requirements on-site. The analyses used to identify opportunity areas are based on existing and available geospatial data that determined the precision of the results. Desirable characteristics differ for detention and volume control facilities; thus, two sets of data compilations were prepared, one showing opportunity areas for detention and one for volume control. This feasibility assessment study showed there are ample opportunity areas for trading. Supply of opportunity area is clearly not a limiting factor in a potential market. However, these areas have not been developed before and incentivizing creation of stormwater detention and/or volume control sites for trading will be important to avoid supply constraints. The GIS tools developed as part of this study will help to identify potential sites to assist with catalyzing this trading initiative.
Site development that uses off-site stormwater detention or volume control will meet the basic precepts of the WMO. Off-site storage upstream of the development site could reduce peak flows upstream, providing additional benefits to the area. Likewise, off-site volume control holds great promise in spurring the creation of the natural, multifunctional sites that enhance the study area and provide ecological and economic benefits.
Stormwater landscapes, sometimes called “landscape as infrastructure” become highly important public and environmental spaces in municipalities. Recent research has revealed that stormwater landscapes create multiple benefits to communities visually, educationally, socially, and environmentally. Therefore, the relative “value” of given sites and their characteristics may differ among different subwatersheds and communities depending on issues and priorities. The methodology for site selection can be adapted for use by watershed or community planners to locate sites with the greatest potential to serve their development priorities and achieve the desired ecosystem benefits.
|Publisher:||Illinois State Water Survey|
|Citation Info:||Allan, K., C. Ballerine, M. P. McGuire, and S. McConkey. 2017. Land and Hydrologic Analysis for Stormwater Detention and Volume Control Trading Exchange in Cook County, Illinois. Illinois State Water Survey Contract Report 2017-04, Champaign, IL.|
|Series/Report:||ISWS Contract Report CR-2017-04|
|Publication Status:||published or submitted for publication|
|Peer Reviewed:||is peer reviewed|
|Rights Information:||Copyright ... University of Illinois Board of Trustees. All rights reserved. This document is a product of the Illinois State Water Survey, and has been selected and made available by the Illinois State Water Survey and the University Library, University of Illinois at Urbana-Champaign. It is intended for research and educational use, and proper attribution is requested.|
|Date Available in IDEALS:||2017-10-25|
This item appears in the following Collection(s)
Contract Reports - Illinois State Water Survey
Report series published by the Illinois State Water Survey from 1953 - date (ISSN 0733-3927)