Learning Objectives Design at an Ecodistrict Scale can Change Washington, DC s Landscape Presenters Elizabeth Miller, ASLA, National Capital Planning Commission Diane Sullivan, National Capital Planning Commission Otto Condon, AIA, ZGF Architects, LLP 1. Discover how Ecodistrict planning and design can achieve greater environmental and economic results. 2. Learn about Washington, DC s unique approach to stormwater management regulations and incentives. 3. Gain insight on how these new approaches are shaping the public realm and infrastructure projects: and the opportunities and challenges to overcome. 4. Understand the application of these new approaches through three case studies: 19 th Street NW, Minnesota Avenue, and 10 th Street SW in the SW Ecodistrict. Introduction Introduction Why District-Scale Stormwater Management? Increases Sustainability Results Greater Financial Incentives Knits the neighborhood together Canal Park, DC 1
District Incentives: 2) Stormwater Credits Untapped Market for Financing for Projects Off-Site Retention Registry: SRCs for Sale Golden Triangle Business Improvement District 19 th St NW Surgical LID Final SRC Sale Prices Today Design Concept Refined concept 2
Goal Existing Proposed Reconstructing a Street to Green a Neighborhood: Minnesota Ave NW DC Great Streets Program Neighborhood Revitalization, 1-1/4 Mile Long Corridor Reconstructing a Street to Green a Neighborhood: Minnesota Avenue East Capitol 3
Minnesota Ave NW Goals 1. Support and enhance the economic viability and expand community livability by improving the retail environment, residential quality of life, and open spaces. 2. A landscape/streetscape design that will enhance the neighborhood downtown retail district and special nodes. 3. An environmental uniqueness to provide for a safe, inviting, and interesting public realm that supports diversity in use and activities. Minnesota Ave NW Framework 1 Main Street 2 Greenway 3 Transitional Mixed Use & Residential 1 2 Main Street Existing 25 Wide Sidewalks, 4 Travel Lanes 4. To promote sustainable mobility through the emphasis of pedestrian, bicycle, transit modes of transportation, while accommodating the needs of vehicular traffic. 3 Main Street Proposed 17 Wide Sidewalks, On-Street Parking, 4 Travel Lanes Minnesota Ave NW Design Sidewalk Plan 15 th St NW Safety LID Purpose Intersection improvement for pedestrian safety Permanent Improvements to replace temporary construction Sidewalk Section Treewell Bioretention Planters Treewell Example 4
15 th St NW Concept Road Diet Triangle Today New Hampshire Florida W Street 15 th Street NW Proposed Scaling up to the Ecodistrict Approach 5
10 th St 7 th St 4 th St The Study Area Planning Approach The National Mall Cotton Annex DOE DOE DOE FAA NPS FAA Education GSA USPS HUD SW Freeway NPS 21 22 Goals/Strategies Water Goals Stormwater Retain/Reuse the rainfall from 80% of the flow. (1.7 Storm Event). and Potable water Reduce municipal potable water use to 70% of what is used now. 92.4 million gallons per year 22 6 gallons/sf/yr District Scale Water Systems Large tanks (under 10 th Street) could hold enough stormwater to provide 71 percent of the total water used in the ecodistrict. C St D St I-395 23 10th Street cross section with below ground tanks 15 6
Independence Ave MD Ave Freeway 10 th St 7 th St 4 th St Urban Ecology Strategies Green Street Infrastructure Green roofs Edible rooftops Green walls Rain gardens Block/District Strategies Native vegetation Healthy soils Shade trees Pervious areas C St D St I-395 Green corridor Enhanced tree canopy 10 th Street, SW Existing Conditions Design Parameters A Street & 3 Bridge Structures 10 th Street Concept Study Design Analysis Evaluated Structure to Inform Potential Tree Rhythm 7
Independence Ave MD Ave Independence Ave Freeway Freeway Lid Banneker Independence Ave MD Ave Freeway D Street Independence Ave Banneker Independence Ave MD Ave Freeway 10 th Street Concept Study 3 Preliminary Design Approaches Hardscape, Softscape, Water National Mall to the Waterfront Maximize Tree Canopy Full growth trees where street Reconstructed Bridge Midspan is constructed on grade w/ Integrated Rainwater Cistern Reinforced bridge structure For tree planting National Mall to the Waterfront 10 th Street SW An Urban Garden Promenade Ground Plane National Mall to the Waterfront An Urban Garden Promenade Garden Room Linear Garden Garden Rooms Magnet Plaza Urban Plaza 8
Independence Ave MD Ave Freeway National Mall to the Waterfront The Urban Plaza There are a variety of design strategies for the Plaza at the peak of the street: National Mall to the Waterfront An Urban Garden Promenade Linear Garden A framed water feature in the median An architectural feature In the median Design encompasses the Right-of-way Design the plaza from building to building Stormwater Infrastructure Study Modeled Green Areas for Water Reduction Flow Through Swale 20% Reduction Flow Through Planter 20% Reduction Roof Intensive 40% Reduction Roof Extensive 100% Reduction Stormwater Infrastructure Study Modeled Daily Water Demand Existing 803,772 Gal/Day 147,686 Efficient Fixtures (20% Reduction in water with 33% increase in development) 73,392 SWECO Target (70% Reduction Municipal Water Use) 650,016 Gal/Day 650,016 Gal/Day 241,131 73,392 656,086 576,624 355,494 Tree Reduction 15 cf/year Impervious 0% Reduction Based on DDOE Stormwater Guidebook Compacted 20% Reduction Natural 40% Reduction 35 Potable Demand Flush Demand ASLA Gap 2014 Annual Meeting and EXPO 9
Stormwater Infrastructure Study Modeled Monthly Water Balance DDOE 10 th Street Corridor Cistern Sizing Stormwater Infrastructure Study gallons/month Jan Feb Mar April May June July Aug Sept Oct Nov Dec Tank Dimensions H 20 x W 20 x L 435 H 20 x W 20 x L 217 Finding new water sources through treatment Stormwater Infrastructure Study Treat stormwater and greywater for non-potable water reuse. Tap well water for potable water needs and replenish it with stormwater and greywater. The system is feasible and has a reasonable payback period. Return on Investment Value of credits will depend on supply and demand SRC = Stormwater Credit 10