HOW CREEKS (should) AFFECT DEVELOPMENT

HOW CREEKS (should) AFFECT DEVELOPMENT Clark Wilson, Community Design + Architecture SCVURPPP Workshop December 7, 2005

Stormwater is not a mechanical system. It is an environmental process, joining the atmosphere, the soil, vegetation, land use, and streams, and sustaining landscapes. Bruce K. Ferguson Source: City of Portl and, OR

What Is Green Community Design? Smart Growth Principles 1. Increased Density 2. Transit and Pedestrian Accessibility 3. Infill and Brownfield Development 4. Bridging Institutional Barriers Green Infrastructure for Water Quality 1. Non-mechanical treatment of storm water run-off 2. Landscape for detention and detention 3. Maximizing water reuse Source: ww.sanlorenzopress.org

Goals for Green Community Design Livability 1. Improve Water Quality 2. Use Land Efficiently 3. Embrace Natural Processes 4. Provide Cost Effective Solutions 5. Create Unique and Attractive Communities and Neighborhoods

A Watershed Strategy to Community Design 1. Land Use Planning Developing land-use pattern at a sub-watershed scale to meet water resource goals 2. Land Conservation Consider value of existing aquatic resources both cultural and ecological 3. Aquatic Buffers Protect streams, wetlands and natural floodplains 4. Better Site Design Reducing impacts at the site level 5. Erosion and Sediment Control Mitigate the impacts of erosion and sediment discharge 6. Stormwater Treatment Practices Integration of structural design solutions 7. Non-stormwater discharges Septic and sanitary sewer spill prevention 8. Watershed Stewardship Programs Necessary to increase public understanding and awareness

Concepts Thinking About Watersheds The Hydrologic Cycle and the Effects of Urbanization Brownfield Conditions Integrating Solutions Development Types and Associated Runoff Volumes

The Hydrograph

Development Type and Effect on Hydrograph

Integrating Solutions: Solving Multiple Issues 1. Stormwater 2. Parking 3. Recreation + Green Space 4. Pedestrian Amenities 5. Multi-modal Streets 6. Habitat Protection + Creation 7. Energy Efficiency 8. Visual Interest

Integrating Solutions T Source: SE WNE Green Stormwater Treatment & Management Source: SE WNET Pedestrian and Bicycle Amenities Convenient Parking Source: SE WNET Aesthetic Benefits EcoTrustParking Lot, Portland OR

Green Community Design Principles

Green Infrastructure the Metro Portland Green Streets Project Green Streets Steering Committee 1. Federal Fisheries & EPA 2. State Fish & Game, DoT, & Environmental 3. Metro Regional Transportation Staff 4. County Public Works & Planning 5. City Transportation & Planning 6. Environmentalists 7. Developers 8. Bicycle Advocates

Lower to Mid Density Design Solutions Detention Infiltration Bio-Filtration

Detention Basins/Wetponds A permanent pool of water that detains and treats runoff Water follows a path of pools created by including jetties and islands Provides ecological habitat (including mosquito-eating predator species) Design as amenity - not a hazard!

Detention Basins - Linear Linear drainage basins provides temporary storage, attenuates flow and allows some infiltration Incorporate into road r.o.w and other leftover spaces Aesthetic designs include stone "walls" and vegetative covers

Infiltration Infiltration Basin Plan Infiltration Basins Similar concept to Rain Gardens A range of scales depending upon context Infiltration Basin with Parking Source: City of Portl and Source: Stor mwat er Center Source: Stor mwat er Cent er Source: City of Portl and Infiltration Basin with Parking

Source: City of Portl and Source: SE WNET Bio-Filtration - Swales School Parking Lot,Portland OR Swale, Cross Section Required slope >1% but < 5% Over 3%, use check-dams Side slopes should not exceed 1:3 Broad range of plant types appropriate/preferred Curb treatments can be flexible, but intake must be controlled Allow appropriate residence time for water to be in contact with vegetation - typical length >120 feet No ponding longer than 48 hours For clay soils, use amended soils or underdrains

Creating Livable Streets Menu Approach to Edge Conditions Green Streets, Metro, Portland,OR

Creating Livable Streets* (*what not to do) Flagstaff,AZ

Creating Livable Streets Green Streets, Metro, Portland,OR

Creating Livable Streets

Mid to High Density Design Solutions Tree Preservation and Planting Permeable and Pourous Paving Infiltration Bio-Retention Bio-Filtration

Tree Preservation and Planting Stormwater Functions Intercept and hold large quantities of rainwater on the leaf surfaces Absorb and transpire large quantities of ground water Remove pollutants from stormwater and stabilize them Canopies shade and cool paved areas, reduce heat pollution

Structural Soils Artificial growing medium encourages root growth and satisfies pavement requirements Gap graded gravels: crushed stone, clay loam, and a hydrogel stabilizing agent StructuralSoils, Cross Section Work well on remediated sites that require new fill Ideal for trees in parking lots, sidewalks, and other constrained spaces

Permeable and Pourous Paving Reduces amount of impervious surface Appropriate for low-speed locations Alameda Installation is key ADA issues Limited applicability in brownfield conditions due to soils and ground water Grass Pavers, Havana, Cuba

Bio-Retention Street Tree Wells 1. Appropriate for urban streetscapes Source: Landscape Ar chi t ectur e 2. Use structural soils to provide sub-surface planting trench 3. Provide better environment for street trees

Creating Livable Streets Menu Approach to Edge Conditions

Creating Livable Streets Green Streets, Metro, Portland,OR

Permeable Paving - Example Project SE 20th & 21st Avenues between Knapp & Lambert Portland, OR Designer: Steven Berger, P.E. City of Portland Bureau of Environmental Services

Bio-retention - Example Project New Seasons Street Planters SE 20th and Division, Portland, OR Designer: Kevin Perry, City of Portland Bureau of Environmental Services

Bio-retention - Example Project New Seasons Street Planters SE 20th and Division, Portland, OR Designer: Steven Berger, P.E. City of Portland Bureau of Environmental Services

Bio-retention - Example Project New Seasons Street Planters SE 20th and Division, Portland, OR Designer: Kevin Perry, City of Portland Bureau of Environmental Services

Bio-filtration - Example Project NE35th & Siskiyou Street Filter Strips Project, Portland, OR NE 36 th Avenue NE Siskiyou Street NE 35 th Place Designer: Kevin Perry, City of Portland Bureau of Environmental Services

Bio-filtration - Example Project NE35th & Siskiyou Street Filter Strips Project, Portland, OR Designer: Kevin Perry, City of Portland Bureau of Environmental Services

High Density Design Solutions Parking Roofs Water Harvesting Bio-retention

Parking Strategies What is the Link between Parking and Stormwater runoff? 1. Reducing Impervious Surface 2. Incorporate Stormwater Systems into Parking 3. Increased Development Potential of Dense Green Infill Source: N\N & CD+A

Shared Parking for Mixed-use Districts Structured or Stacked Parking 1. Encourage parking structures (with design controls), or other vertical parking strategies like valet and parking lifts 2. Guide Design - Greens stormwater treatments, Control curb cuts, blank walls, and other design controls Source: N\N & CD+A

Site Design Strategies for Compact Development

Green Roofs Extensive Green Roofs 1. Bio-Filtration, evapotranspiration- can intercept 10 to 100% of the rain that falls on them ch Source: Ameri can Hydr ote 2. Light, thin layer of planting medium and vegetation Gap Corporate headquarters, San Bruno,CA 3. Maintenance is minimal but key-especially during plant establishment period Source: City of Portl and 4. Not intended for frequent access ExtensiveGreen Roof Cross Section

Green Roofs Extensive Green Roofs 1. Create savings through reduced energy demand c. Source: Roofscapes, In 2. Provide bird and insect habitat 3. Provide aesthetic value and benefits 4. Feasible on contaminated sites 5. Potentially feasible for retrofit projects A merican Motors Corporate Headquarters,Irvine

Green Roofs Intensive Green Roofs 1. Bio-filtration, evapotranspiration of runoff Oakland Museum Garden Terraces, Oakland, CA 2. Public or private access to gardens, open space or recreation facilities 3. Feasible on contaminated sites 4. Higher economic/structural demands- less suitable for retrofit projects Kaiser Parking Garage, 5 th Level Roof Garden, Oakland,CA

Infiltration Infiltration Trenches Collect storm water and slowly infiltrate or attenuate Can employ filtering devices to pre-treat storm water e Source: Landscape Ar chi t ect ur Can connect to existing storm sewer system Source: City of Portl and Infiltration System, Portland, OR Pima Community College, Tucson, AZ

Water Storage and Harvesting v Source: www. eere. ener gy. go Cisterns 1. Collect rainwater from roof and store it for irrigation and other non-potable uses 2. Attenuate peak runoff flows Source: Landscape Ar chi t ectur e CBF MerrillEnvironmental Center, Annapolis, MD 3. Conserve potable water resources 4. Cisterns can be located above or below ground 5. System should include a roof washer or first flush device Cistern Detail

Bio-Retention oc. Source: City of Portl and; Murase Ass Rain Gardens 1. Utilize soil, plants, trees, hardscape elements to support and enhance infiltration and bioremediation 2. Proven method of bioremediation. 3. A broad range of plant types can be appropriate and are preferred BES Water Pollution Control Lab, Portland, OR 4. Can provide habitat and aesthetic value

Bio-Retention Source: City of Portl and Drip-Line Planters 1. Suitable for contaminated Sites- planter prevents exfiltration to underlying soils Source: City of Portl and Drip-linePlanter, Cross Section 2. Feasible for sites with space constraints 3. Feasible for retrofit projects 4. Should include a roof washer or first flush device Buckman Heights Apartments, Portland,OR

Bio-Filtration Swales Swale bottom to be at least 4-6 ft. wide Side slopes should not exceed 1:3 Avoid erosion - use cobbles and no V-ditches Use rough calculation of 1200 sq.ft.of usable swale per acre of impervious surface ( Start at the Source ) Inspect, mow and water Resource: Darren Greenwood Public Services, Water Resources, City of Livermore Parking Lot, Livermore, CA

Other Devices and Programs Source: Landscape Ar chi t ectur e Rain Catchers 1. Intercept rainfall for storage and harvesting 2. Unique urban design elements-- lend visual character and identity Source: New Leaf Gal ery/scul pture Site Phoenix Office Complex with Rain Catchers Sun Shades 1. Shade sidewalks, reduce heat pollution in runoff 2. Provide pedestrian amenity 3. Create visual interest Sun Flower Shades,Palo Alto, CA

Selecting and Sizing Design Solutions Combined Solutions: A A. Green Roof B. Cisterns C. Rainwater garden with drip line D B D. Drip-line planter E. Bio-retention tree well E C F F. Infiltration basin

Selecting and Sizing Design Solutions Design Considerations 1. Opportunities to reduce impervious surface coverage: reduce surface parking? reduce building footprints? 2. Can passive or intensive green roofs be integrated into design? 3. Can turf be irrigated with captured rainwater? Or replaced with rain gardens? 4. Can pervious paving be used as a hardscape material? D E A C F B

I never learned to doubt that the city was part of nature Cities must resist the habit of fragmenting nature. Only by viewing the entire natural environment as one interacting system can the value of nature be fully appreciated. Anne Whiston Spirn