Ted Turner Drive Resilience Corridor Challenge

Transcription

1 Ted Turner Drive Resilience Corridor Challenge Green Infrastructure Cory Rayburn, Atlanta Department of Watershed Management #TTDresilience

2 Mayor Kasim Reed Mayor Keisha Lance Bottoms Building Green: Atlanta s Green Infrastructure Approach 1/27/2018 Ted Turner Drive Resiliency Corridor Challenge Kickoff 2018 Presented by: Cory Rayburn Jo Ann J. Macrina, PE, Commissioner Kishia L. Powell, Commissioner Department of Watershed Management Department of Watershed Management

3 Presentation Outline Overview of Atlanta s Green Infrastructure Program What is Green Infrastructure? Why Green Infrastructure in Atlanta? What are the standards? First five years of implementation Single Family and Small Commercial Design manuals Lessons Learned Addressing Neighborhood Flooding Historic 4 th Ward economic and social benefits Southeast Atlanta Green Infrastructure Initiative combined sewer capacity relief Upper Proctor Creek Capacity Relief: Rodney Cook, Sr. Park in Historic Vine City

4 Background City s Department of Watershed Management Serves 1.2 million (450,000 night) Consent Decree CSO completed 2008 SSO extension granted nd Highest W&S rates in the country Stormwater Utility Fee Adopted in 1999 Overturned - $7 million refunded

5 How Urbanization Causes Flooding

6 Urbanization effects on Water Quality Schueler, T. R., L. Fraley-McNeal, et al. (2009).

7 Problems of Urban Watersheds Flashy stream hydrology causes in stream erosion and low base flow

8 What is Green Infrastructure? Gray vs. Green Slow, Infiltrate, and Clean Stormwater

9 What is Green Infrastructure? An interconnected natural or engineered system that mimics undeveloped hydrologic functions Capture the first 1.0 of rainfall Infiltration Evapotranspiration (uptake of water by plants + evaporation) Reuse through rainwater harvesting

10 Examples of Green Infrastructure Soil Restoration Bioretention Green Roofs Permeable Pavements Undisturbed Pervious Areas (greenspace) Vegetated Filter Strips Dry Swales Site Reforestation Downspout Disconnection Rain Gardens Stormwater Planters Dry wells Rainwater Harvesting Infiltration Practices

11 Examples of Green Infrastructure Bioretention Adair Park Bioswale - Edgewood Townhomes Permeable Pavers - Urban Market on Howell Mill Stormwater Planter - Whitehall Terrace ROW Permeable Pavers - 6 th and Juniper Bioswale - Klaus Building - GT campus

12 Amended Stormwater Management Ordinance Requires Green Infrastructure on single family infill and commercial development/redevelopment 1.0 Runoff Reduction Volume (RR v ) Mandatory versus voluntary No direct financial incentives Low threshold for compliance Process for success Technical Advisory Committee Robust stakeholder involvement Give and take approach Outreach, education, and technical guidance documents

13

14 Stormwater Management Manual Initially Adopted the Coastal Stormwater Supplement Provides design criteria and credit system for green infrastructure Dependent on soil type Includes Green Infrastructure / Runoff Reduction practices Does not address SFR or Small Commercial projects

15 Simplified Design Approach

16 SFR Manual GI for Single Family Residences Provides a list of acceptable practices Reduces the need for complicated calculations Provides tear-off details and construction specification for each practice Simplifies the review and approval process

17 General Info & Tear-off Details

18 Easy-to-Use Sizing Tables Impervious Area Treated Design Options Sizing Charts Options within practical range Accommodate actual rainfall and runoff data Allows for median infiltration duration Assumes in/hr infiltration rate Practice Size Modified French Drain Example

19 Small Commercial Manual GI for Small Commercial For projects that add/replace between 500 and 5,000 ft 2 of impervious surface Catered to small urban redevelopment and addition projects Supplement to CSS and Blue Book Provides clarification to specific issues

20 Sizing Charts for each Practice

21 Example Design

22 Typical Details

23 Retrofit examples: Landscape Islands

24 Example Landscape Plans

25 Innovative designs included Upturned S Underdrain Creates saturated zone, aids in denitrification, additional infiltration in poor draining soils

26 Tracking Green Infrastructure with GIS Permitted Sites Since Feb Commercial 3,200+ Single Family Residential GIS attributes contain: Owner Date of completion Copy of I&M agreement Inspections information Green infrastructure BMPs Detention BMPs Runoff Reduction Volumes

27 Green Infrastructure can compete for space Creativity with site layout Upfront coordination between Civil, LA, and Architect Dual purpose practices: permeable pavement landscape islands bioretention green roof underground detention/infiltration systems Able to meet tree planting and runoff reduction requirements with one practice

28 Infiltration Practices in Atlanta Soils analysis required for all commercial sites Infiltration rates, high water table, bedrock, contaminated soils Compaction of Silt and Clay soils Loosening compacted soils on redevelopment sites Prevent compaction during construction Innovative designs (upturned underdrain) to encourage surface drainage and promote infiltration in clay soils Erosion control Phasing installation to prevent sedimentation issues Installation of appropriate BMPs

29 Erosion Control and Phasing

30 Green Infrastructure Task Force City staff plus partners Watershed, Public Works, Parks & Recreation, Mayor s Office of Resilience, Planning and Community Development, Aviation Atlanta Beltline, The Conservation Fund, American Rivers, Invest Atlanta, Chattahoochee Riverkeeper, Trees Atlanta, etc. Task Force Origins and Goals Began through a Peer Exchange trip (2012) to Philadelphia Create Best-in-Class program Focus on CIPs and processes Recently published Strategic Action Plan

31 Strategic Action Plan Strategic Action Plan Goal Through policies, projects, and partnerships, install enough GI to reduce an additional 225 MG runoff volume each year Actions - Subcommittees Project Implementation Policy, Funding, & Planning Partnering & Outreach Data Tracking & Technical Analysis

32 Name that site!

33 Historic 4 th Ward Capacity Relief

34 Historic Fourth Ward Park Opened Combined Sewer Capacity relief

35 Nature Influenced Design

36 Aerating Fountain

37 Which would you prefer?

38 Spurring Economic Development $500M in Redevelopment Apartments Condos Ponce City Market

39 April 16, rain event

40 Three days later

41 April 16, rain event

42 Three days later

43 Southeast Atlanta Green Infrastructure Initiative Combined Sewer Capacity Relief

44 Contributing Conditions Point of Surface Flooding July 2012 (Peoplestown)

45 Historical Perspective Historical Perspective Map of Atlanta 1886 Ormond Peoplestown Junction Box Location

46 Peoplestown Flooding

47 Phase 1 Projects- Completed

48 Phase 2: Permeable Roadways 4+ miles of Permeable Pavers

49 Permeable Paver System The paver system is made up of the following components: #4 Stone #57 Stone #89 Stone LLDPE 40 Mil Liner Permeable Pavers

50 Unique Design Considerations Steep slopes - impermeable liner check dams used

51 Construction Sequence Excavation, aggregate reservoir, paver installation

52 Completed Streets

53 Boone Blvd Green Street

54 Proctor Creek Watershed - UWFP

55 Basin wide planning efforts

56 Boone Blvd Green Street BeltLine Lowery Blvd Project Extent Northside Drive

57 Before and After Leveraging Funding and Partnerships Invest Atlanta $1M Grant for streetscape improvements Renew Atlanta $1.1M EPD 319(h) Grant $387K Total $8.9M

58 Current Photos

59 In Summary Utilizing green infrastructure as a tool to address historic drainage issues and water quality is possible, practical, and can spur economic growth Coordinating w/ other City Departments and developing partnerships is vital Providing a robust outreach and education program and developing relevant guidance documents aids in transition Leading by example is key

60 Questions? Cory Rayburn, CPESC, CFM, EIT, Env SP, MSCE Watershed Manager II