Johanna McCrehan, Urban Designer, Georgia Conservancy

Richard Dagenhart, RA, Associate Professor of Urban Design, Georgia Institute of Technology

March 31, 2014Park Pride Parks and Greenspace Conference

Urban Designand StormwaterandUrban Design

Georgia Conservancy + Georgia Tech Urban Design Studio

Urban Design and Stormwater

1. Why Stormwater?2. Understanding Stormwater Management3. Conservancy Blueprints + Urban Design Studios

Colonial Homes, Bobby Jones Golf Course and the Peachtree Creek Watershed

Maddox Park, Boone Boulevard and the Proctor Creek Watershed

Pittsburgh, University Avenue and the McDaniel Creek Watershed

Ansley Mall and the Clear Creek Greenway and Watershed

4. Conclusions: Urban Design and Stormwater

STORMWATER IS AN URBAN DESIGN PROBLEM

AND

URBAN DESIGN IS A STORMWATER PROBLEM

Georgia Conservancy

GC - Blueprints for Successful Communities Sponsored by

The Home Depot Foundation The Sartain Lanier Foundation, Inc.

Georgia Tech Urban Design Studio School of Architecture, School of City and

Regional Planning Richard Dagenhart, RA, Associate Professor Dr. Tom Debo, PE, Professor Emeritus

Why Stormwater?

Research-based Blueprints for Successful Communities

Education through partnerships

Statewide initiatives and technical assistance

Regional Atlanta Watersheds:

Upper ChattahoocheeUpper Middle ChattahoocheeUpper FlintUpper OcmulgeeEtowah CoosawatteeUpper Oconee

ARC area

www.atlantaregional.com

GEORGIA’S 52 WATERSHEDS

Understanding Stormwater Management

Stormwater problems have been defined as the control of peak rates of runoff from new urban development

The engineering solution: control post-development runoff from specific rainfall events (5-, 10-, 100-year storms) so they do not exceed pre-development runoff

The design solution: construct a storm detention basin at the development site’s drainage outlet

Criticism of Stormwater Management Practices

Evidence shows that end-of-pipe stormwater solutions do not address the hydrologic changes induced by new development, nor do they consider stormwater quality

The problem in previous approaches was to focus on individual development sites rather than the processes of water flows … as they move from the individual development sites into the larger ecological system of urban waterways or into the equally important migration into ground waters.

Low Impact Development (LID) – The New Approach

Stormwater management focuses on both water quantity and water quality

Stormwater management incorporates natural processes with mechanical processes to design hydrologic solutions

Attention is directed as close to the source of stormwater as possible, not the exit from the site

Stormwater and Urban Design

The LID goal is to allow urban development to occur in most situations, but require that the project be designed to limit hydrologic impacts

The LID objective is to have urban development approximate the hydrologic characteristics of rural or undeveloped land

When LID is broadened beyond a single parcel of land, the design challenge expands from site design to urban design.

Urban Design Studio:Research + Design

Questions

HOW CAN URBAN DESIGN ADDRESS

STORMWATER SOLUTIONS?

HOW CAN STORMWATER ADDRESS

URBAN DESIGN SOLUTIONS?

Stormwater in Context

Four sites along the BeltLine, where the BeltLine Subarea Plans did not specifically address stormwater issues

Pittsburgh, University Avenue and the McDaniel Creek Watershed

Maddox Park, Boone Boulevard and the Proctor Creek Watershed

Ansley Mall and the Clear Creek Greenway and Watershed

Colonial Homes, Bobby Jones Golf Course and the Peachtree Creek Watershed

Urban Design, not engineering, is the focus of the projects – the concern is the relationship of stormwater solutions, environmental quality, and the future of public and private developments for housing, commercial and other uses.

4 SITES

PITTSBURGH, UNIVERSITY AVENUE AND THE MCDANIEL CREEK WATERSHED

EXISTING CONDITIONS

WATERSHED ANALYSIS

HYDROLOGY

PART ONE: PITTSBURGH NEIGHBORHOOD

PITTSBURGH NEIGHBORHOOD – STORMWATER PLAN

GREEN STREETS

PITTSBURGH NEIGHBORHOOD

PART TWO: UNIVERSITY AVENUE

UNIVERSITY AVENUE SITE – SUBDIVISION (LOTS, BLOCKS, STREETS)Pittsburgh block width – 200 ft. – same as New York City – accepts any density

UNIVERSITY AVENUE STRATEGIES

UNIVERSITY AVENUE MASTER PLAN

BIRD’S EYE VIEW OF CENTRAL PARK

CENTRAL PARK – LOOKING SOUTH TOWARD THE BELTLINE

PART THREE: MCDANIEL BRANCH

MCDANIEL BRANCHGREENWAY PLAN

MASTER PLAN

MADDOX PARK, BOONE BLVD AND THEPROCTOR CREEK WATERSHED

EXISTING CONDITIONS

HYDROLOGY

URBAN ANALYSIS

EXISTING PROPOSAL URBAN DESIGN STUDIO PROPOSAL

ANSLEY MALLCLEAR CREEK GREENWAY AND WATERSHED

EXISTING CONDITIONS

EXISTING SITE FEATURES

SCHEMES

STRATEGIES

PROPOSED SECTIONS

SUBDIVISION PLANS AND PHASING

PERSPECTIVES OF NEW WATER SYSTEM

CLEAR CREEK GREENWAY MASTER PLAN

COLONIAL HOMES, BOBBY JONES GOLF COURSE AND THE PEACHTREE CREEK WATERSHED

EXISTING CONDITIONS

URBAN DESIGN AND STORMWATER TACTICS

STORMWATER PERFORMANCE

STORMWATER PERFORMANCE

ECO-GOLF COURSE 100 YEAR STORM EVENT

CONCLUSION 1

EVERY project – public or private, no matter how large or how small, must begin with an understanding of its associated drainage basins.

For urban design – watersheds always come first!!!!

GEORGIA’S 52 WATERSHEDS

CONCLUSION 2

The location of a project in its watershed shapes both urban design and stormwater decisions.

For urban design, site based solutions are the wrong approach. Stormwater policies and regulations must recognize this fact. UNIVERSITY AVENUE,

PITTSBURGH AND McDANIEL BRANCH GREENWAY

CONCLUSION 3

High performance site design, for urban design and stormwater, can combine greenways as incentives for revitalization and new development.

MADDOX PARK, BOONE BOULEVARD AND THE PROCTOR CREEK

WATERSHED

CONCLUSION 4

Urban design can MANAGE stormwater when flooding cannot be eliminated.

Combine retention and detention in greenways, swap land out of flood plains, create new development opportunities.

COLONIAL HOMES, BOBBY JONES GOLF COURSE AND PEACHTREE

CREEK

STORMWATER IS AN URBAN DESIGN PROBLEM

AND

URBAN DESIGN IS A STORMWATER PROBLEM

QUESTIONS?