SUSTAINABILITY: Principles, Techniques, Design, and Regulations Ann Audrey City of Tucson Office of Conservation and Sustainable Development January 2009
6 Steps to creating a sustainable site 1. Describe site characteristics 2. Inventory needs and products 3. Apply sustainability principles 4. Apply sustainability techniques 5. Incorporate brainstorm results 6. Develop sustainable design
Step 1. Describe site characteristics SITE CONTOURS Gravity controls the flow of many elements Determine design implications
Step 1. Describe site characteristics HUMAN AND ENVIROMENTAL CONTEXT Surrounding Land ownership Watershed context Biotic communities Western hemisphere Design implications
Step 1. Describe site characteristics NATURAL CONDITIONS Climate Geology Hydrology Solar orientation Rainwater drainage Wind patterns Fire sources Cold air drainage Soils and erosion Flora Fauna Many others, specific to the site Design implications
Step 1. Describe site characteristics HUMAN-BASED CONDITIONS Land use and land condition on site On-site infrastructure: power lines, water lines, buildings, etc. Off site infrastructure: roads, railroads, utility poles, etc. Traffic noise Artificial light Many others, specific to the site Design implications
Step 2. Inventory needs and products: Site Elements Needs Products Characteristics Building materials Access Utilities Human maintenance Water Food Shelter Community Microclimates: shade, reflected light & heat Water runoff Hosts human eyes Work Attention Ideas Waste Can use recycled & earthen materials Expensive Long lasting Not movable Creative Busy Designers Consumptive Water Soil nutrients Sun Moderate care Shade Fruit, leaves, twigs Wood Vertical structure Host birds and wildlife Affect soil quality Grow to meet its water supply Tallest living element Water Sun Soil Nutrients Lots of care Food Fiber Detritus Fragrance and color Sensitive to microclimates Sensitive to insect pests Seasonal
Step 3. Apply sustainability principles Place every element in relationship to others so they assist each other. Meet the needs of one element with the products of another.
Step 3. Apply sustainability principles Each element performs multiple functions
Step 3. Apply sustainability principles Each important function is supported by multiple elements
Step 3. Apply sustainability principles Plan for efficiency by placing elements according to their need for human attention.
Step 3. Apply sustainability principles Use local biological and mineral resources rather than fossil fuel-based resources, when possible.
Step 3. Apply sustainability principles Use and accelerate natural plant succession to establish favorable sites and soils. Use a diversity of beneficial species for a productive, interactive system
Step 3. Apply sustainability principles Use edge and natural patterns for best effect
Step 3. Apply sustainability principles Collect and recycle energy, materials, and elements on site
Step 4. Apply sustainability techniques Rainwater harvesting Gray water reuse Passive solar design Active solar collection for electricity and heating Strawbale, rammed earth, adobe and other natural building materials Wind-power generation Growing native and locally adapted foods Composting Gleaning native plants Earth ovens, outdoor kitchens Water gardens and ponds Community networking And many more..
Step 4. Apply sustainability techniques Example: Applying Water Harvesting Principles and Techniques 1. Start harvesting at the top of the watershed 2408 2408 2408 2408 2408 24 24 24 24 24 2402 2406 2406 2406 2406 2406 2406 2424 2424 2424 2424 2424 NG G WASH RD 2412 2412 2412 2412 2412 2410 2410 2410 2410 2410 2414 2414 2414 2414 2414 2416 2418 2418 2418 2418 2418 N CAMINO DE OESTE W SWEETWATER SWEETWATER SWEETWATER SWEETWATER SWEETWATER DR DR DR DR DR 2422 2420 2420 2420 2420 2420 2426 2426 2426 2426 2426 2420 2428 2428 2428 2428 2428 2. Capture water in multiple small catchments
Step 4. Apply sustainability techniques 3. Collect, slow and infiltrate the water 4. Raise paths; lower adjacent planting areas
Step 4. Apply sustainability techniques 5. Prepare for overflow 6. Apply mulch to reduce evaporation
Step 4. Apply sustainability techniques 7. Plant appropriate vegetation 8. Put harvested water to beneficial use 9. Inspect, adapt and maintain your system
Step 4. Apply sustainability techniques Microbasins Swales
Step 4. Apply sustainability techniques Infiltration Basins French drains
Step 4. Apply sustainability techniques Curb cuts Porous pavement
Gabions & Weirs Step 4. Apply sustainability techniques
Tanks Step 4. Apply sustainability techniques
Step 5. Incorporate brainstorm results Faithfully record ideas from meetings Prioritize concepts
Step 6. Create a sustainable design Assimilate characteristics, principles, techniques, and brainstorm into site design. Name at least four good reasons for placing each element in its location!
Tucson s newly adopted Gray Water Ordinance Title: Residential Gray Water Ordinance (Ordinance No. 10579) Adopted: September 23, 2008 Effective: June 1, 2010 Applies to: New single family and duplex residential units Primary requirement: Installation of segregated drains for graywater and blackwater plumbing fixtures to allow future gray water distribution systems
Major Elements of New Greywater Ordinance Detailed Requirements: - Graywater drains stub out three feet from building foundation - Gravity-fed drain for washing machines - All gray water systems must comply with ADEQ codes for residential gray water use Allows: - Installation of graywater distribution system is not included in the requirements
Tucson s current water harvesting requirement: make maximum use of site storm water runoff for supplemental irrigation Applies to: New or redeveloped, - Commercial sites - Subdivisions - Public buildings - Public rights-of-way
Tucson s new Commercial Water Harvesting Ordinance Title: Commercial Rainwater Harvesting Ordinance (Ordinance No. 10597) Adopted: October 14, 2008 Effective: June 1, 2010 Applies to: New Commercial development that is nonresidential Primary requirement: Offset 50% of landscape water demand using harvesting rainwater
Elements of New WH Ordinance Detailed Requirements: - Rainwater Harvesting Plan - Water budget - Metering of outdoor water use - Soil moisture-based irrigation control - Annual reporting Allows: - Three years to establish plants - Relief from 50% requirement during drought - Goal can be met using earthworks. Tanks not necessary
Monthly Low-Water-Use Plant Demand vs Adjusted Rainfall, Tucson, Arizona 2.5 Annual Average Amount (inches) 2 1.5 1 0.5 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Months Plant Water Demand (Arizona Department of Water Resources) Adjusted Rainfall (calculated) Design implications Determine ratio of water harvesting catchment area to plant canopy area that is needed to meet plant water demand
Design factors Water supply = 50% rainwater plus 50% potable April, May, June = 36% annual plant water demand March is the next limiting month for plant water demand Plant canopy area drives needed water harvesting catchment area Design water harvesting area to meet March plant water demand 1.32 inches March water demand per sq ft of canopy = 3.1 0.43 inches adjusted March rainfall per sq ft of canopy Therefore, harvest rain from 3 times the canopy area to meet March demand Water harvesting catchment area Tree canopy area
Monthly Low-Water-Use Plant Demand vs Harvested rainfall, Tucson, Arizona Annual Average Amount (inches) 4 3.5 3 2.5 2 1.5 1 0.5 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Months Plant Water Demand (Arizona Department of Water Resources) Harvested Rainfall (based on March data need 3:1 catchment ratio) Design implications Use 50% potable water supply to meet April, May, June demand and additional demand if needed. 50% harvested rainwater should meet or exceed the rest of demand.
CELEBRATE RAIN!
CELEBRATE RAIN!