1. Water Conservation Strategies for Commercial Landscaping

2. Increasing demand

3. Metro Atlanta water use Single Family residential water consumption = 191 MGD to 280 MGD (149 GPCD) Outdoor water consumption = 38 MGD to 56 MGD

4. Regional Limitations to Water Resources 98% of Atlanta’s water needs are supplied by surface water sources 80% of surface water is supplied by the Chattahoochee Atlanta’s location at the headwaters limits the supply Bedrock limits groundwater sources Increasing demand: +1,000,000 residents in 10 years SOURCE: ARC

5. 1.Minimize water demand 2.Meet demand with non-potable water 3.Deliver water efficiently 3 Steps for Outdoor Water Conservation

6. Minimize Water Demand Use regionally native or Drought-tolerant non-invasive species Minimize the use of turf

7. Keep stormwater runoff on-site to nourish the landscape Minimize Water Demand

8. Protect and restore healthy soil. Minimize Water Demand

9. Meet Demand with Non-potable Water Benefits of Rainwater Harvesting Rainwater is free – helps to reduce utility bills Can eliminate costly infrastructure Not subject to watering restrictions Eliminates the need for water softeners if used indoors Rainwater is the most pure water (chemical free) to use on plants, vegetables, etc. Reduces runoff to storm drains Entire system costs range from $.75/gallon to $2/gallon with a payback period of less than ten years (NCSU). Important part of an overall strategy to conserve water resources

10. History of Rainwater Harvesting Rainwater harvesting is an ancient technique dating back as far as 4,000 years ago. Still widespread in India, Australia, the Caribbean and other regions with poor public infrastructure and dry climates. Enjoying a resurgence in the US, partly due to superior water quality and partly due to the desire to reduce consumption – an estimated 100,000 systems are in use. Currently, there are no national standards governing rainwater harvesting. However, rainwater harvesting is currently mandated for new construction in Bermuda, US Virgin Islands and other Caribbean islands. Incentives are in place to offset costs in Texas (maybe in the southeast soon?) Simplest systems are land-based and may consist of earthen berms and reservoirs. More complex systems take many forms… Meet Demand with Non-potable Water

15. Memorial Garden @ the SLC (Photo courtesy of Kevin Kirsche, University Architects)

22. Components of A Rainwater Harvesting System Meet Demand with Non-potable Water

23. The supply (amount that can be collected and stored) must equal or exceed the demand (anticipated amount that will be used) Water Balance and System Sizing Meet Demand with Non-potable Water

24. Assumptions: demand of 3,000 gal/mo; collection efficiency of 85%;.62 gal/S.F. of catchment per inch of rain; 10,000 gallon storage capacity; 1,000 gallon starting volume; Dallas, Texas location System Sizing Example Meet Demand with Non-potable Water

25. Drip Irrigation Deliver Water Efficiently Avoid waste through overspray and evaporation. Deliver directly to the plant.

26. Irrigation Zones WeatherTrak Controller Apply water only when and where it is needed. Rain Sensor Soil Moisture Sensor Deliver Water Efficiently

27. The Lady Bird Johnson Wildflower Research Center – Austin, Texas 70,000 gallons of total cistern storage capacity 17,000 S.F. of catchment area Broken up into several catchments and cisterns throughout the site Aesthetic / experiential system created by conveying water through aqueducts to exposed above-ground cisterns Local materials create a sense of place Used solely for irrigation

28. The Lady Bird Johnson Wildflower Research Center – Austin, Texas

29. The Southface Energy Institute – Atlanta, Georgia 1,750 gallon rooftop cistern for toilet flushing and mechanical demands Below-grade cistern stores site runoff for non-potable uses (irrigation) Collector area should yield approximately 42,000 gallons per average year Combined with efficient interior fixtures, this results in a total water savings of 150,000 gallons per year when compared to a comparable conventional building – a 74% reduction.

30. Potable water should not be used for landscape irrigation. However, allowance should be made for plant establishment (first 1-3 years). Although the landscape industry has taken some short-term hits due to the drought, there are tremendous long-term business opportunities: –Rainwater catchment design and installation –Low-impact stormwater design and installation –Xeriscape design and installation –Research / Propogation of new landscape plants –Landscape management –Efficient irrigation design and recycling –Soil restoration –………… Final Thoughts

31. Resources: http://www.twdb.state.tx.us/assistance/conservation/alternative_technologies/ rainwater_harvesting/rain.asp http://www.twdb.state.tx.us/assistance/conservation/alternative_technologies/ rainwater_harvesting/rain.asp