LID Practices in Urban Areas Example Projects and Opportunities in Redevelopment

Transcription

1 LID Practices in Urban Areas Example Projects and Opportunities in Redevelopment 2011 Low Impact Development Symposium Philadelphia, Pennsylvania September 25-28, 2011 Lisa Hair Senior Environmental Engineer USEPA Office of Water Brian Kuchar, R.L.A., P.E. Sr. Landscape Architect

2 Acknowledgement and Project Partners The is working with the EPA s Office of Wetlands, Oceans, and Watersheds to develop a handbook on Green Infrastructure (GI) and Low Impact Development (LID) Best Management Practices to encourage communities and developers to incorporate GI/LID into their projects. The handbook is intended to be part of a series of EPA Green Infrastructure Municipal Handbooks. The handbooks are available at the EPA website listed below:

3 Background

4 Highlight projects from the 10 EPA regions of the US, of different size communities and climate types Objectives Projects demonstrate a wide range of development conditions and scenarios; Cost effectively meet the identified performance goals; provide a range of ancillary benefits and can be used to reduce excess runoff volumes and/or pollutants.

5 Selection Process

6 Selected Project Case Studies Region 1 Watch Factory Waltham, MA Region 2 Queens Botanical Gardens Queens, NY Region 3 Radian Apartments, Philadelphia, PA Kensington CAPA High School Philadelphia, PA Region 4 Aiken Green Infrastructure Aiken, SC Region 5 Uptown Normal Circle Normal, IL Menomonee Valley Milwaukee, WI

7 Selected Project Case Studies Region 6 Railyard Park Plaza Santa Fe, NM Central Corridor Light Rail Transit St. Paul, MN Region 8 Stapleton Airport Denver, CO Region 9 Mint Plaza San Francisco, CA Region 10 Pacific Avenue Bremerton, WA, Thornton Creek Seattle, WA

8 Central Corridor Light Rail Transit- St. Paul, MN History Located on University Ace, one of the oldest streets in the metro area Heavily urbanized 100 acre watershed with 93% impervious cover 120 ft. ROW High GW, contaminated soil Description 11 mile Light Rail development Capitol Region Watershed District (CRWD) infiltration requirements Innovated integrated tree trench system Region 6

9 Problem Develop a Light Rail line in a 120 ft ROW Maximize infiltration to meet the CRWD requirements in a highly impervious environment Contamination & High Groundwater in some areas Current drainage discharges untreated to the Mississippi portions of which are impaired for turbidity, nutrients and bacteria

10 Stormwater Design Solution Maximize reduction of stormwater runoff volumes through infiltration via an innovative Tree Trench Design and permeable pavers CRWD rules require infiltration of runoff from a 1 storm Per CRWD rules the project meets approximately 50% of their rule but achieves all infiltration attainable Minimize polluted stormwater runoff to the Mississippi

11 GI and LID Practices Integrated Tree Trench System 3.56 miles Pervious Pavers 1.42 miles

12 Construction Costs Total Cost of project = ~$957,000,000 Tree Trench System Costs -$ 2,803,800 Total impervious area = ~93.5 acres Cost Cap -$30,000/Impervious Acre -Cost cap achieved at $2,803,800

13 Highlights Largest public works project in Minnesota history ($) The project would not have been possible without LID practices Effective implementation of infiltration requirements Adding/replacing street trees to soften urban landscape along the rail corridor Use of runoff to water urban landscape reduce irrigation use Links urban areas and promotes revitalization along the rail line Promote public transportation

14 Thornton Creek- Seattle, WA Site 9.1 Acres Within the Thornton Creek Watershed Highly developed watershed Drains to Lake Washington At 11.6 square miles, it is Seattle s largest watershed Region 10

15 Thornton Creek- Seattle, WA History 9-acre paved parking lot 1,800 concrete pipe that carries base flow from the watershed above to the South Fork of Thornton Creek Political controversy and litigation stymied development Description 6.4 acres of multi-family housing, commercial, and market-rate senior housing 2.7 acres of public green space (water quality channel)

16 The Problem Surface runoff from impervious surfaces has been cited as one of the leading causes of the continuing degradation of the Puget Sound and associated lakes, rivers and streams Contradicting goals for developing the site created an impasse to development Controversy developed into a political logjam for over 15 years and site remained under utilized

17 Stormwater Design Solution Outcome of political compromise between developers and Thornton Creek advocates Improves watershed water quality by removing sediments and associated pollutants from 91% of the annual runoff from the 680 acre watershed Designed to remove 40-80% of TSS and associated pollutants Meets the target flow rate corresponding to 91% of the average annual rainfall volume over the subbasin Based upon standard guidelines established by the Washington State Department of Ecology (DOE) Limited amount of space and a target flow of 13 cfs, required a creative solution which diverged from standard guidelines

18 GI and LID Practices Water Quality Swale A series of cascading weirs, pools, boulders and large woody debris End of pipe treatment

19 Schematic Plan UPPER CASCADE WATER QUALITY CHANNEL OUTLET TO THORNTON CREEK 60 PIPE DIVERSION STRUCTURE

20 Construction Costs Total project cost = $14.7 Million Includes: Design and land acquisition Upslope plantings Pedestrian walkways Walls and railings 340 (14,810,400 sf) acres of impervious area Approx. $1.00 per sf of impervious area

21 Project Highlights Public/Private Partnership Collaborative team effort of consultants, public agencies, community groups and private developers Significant part of urban redevelopment Unique end of pipe treatment Project provided much more than stormwater quality treatment

22 Summary The intent of the manual will be to demonstrate How the use of GI can improve urban redevelopment by creating more livable places. How costs compare to conventional drainage systems. Performance of pollutant removal Available on EPA s Green Infrastructure (GI) website Provide a valuable resources for municipalities, designers, and developers. Provide cost/benefits/performance data and demonstrate affordability of these practices. dbook.cfm. As a follow up, the next section in the handbook will be developed and focus on; Stormwater/GI policies adopted by municipalities to incorporate LID/GI practices in a dense urban setting.

23 Questions?