1. Delivering Green Space Benefits: Irrigation planning implications Geoff Connellan G&M Connellan Consultants geoff.connellan@bigpond.com Website: www.geoffconnellan.com.au

2. What is special about green space? I.The nature and range of services to be provided II.Quality and/or standard of services III.Reliability of service delivery/supply

3. Green Space Potential Landscape Outcomes or Services Provided  Exercise – Organised sport & walking  Microclimate modification (UHI)  Contact with nature  Habitat protection  Biodiversity preservation  Aesthetics

4. MESSAGE Quality Green Space = Liveable Cities Water/Irrigation has a critical role.

5. Some Challenges for Green Space  Lack of security of water supply  Low water quality  Footprint of WSUD systems  Maintenance of WSUD systems  High cost of potable water  Cost of recycled water – capital and operating

6. What is role of irrigation? Provides critical green space in urban environments where vegetation growing under natural (rainfall only) conditions cannot deliver the required services. Main Applications - Health  Exercise – Active and passive  Microclimate modification, extreme temperature reduction including Urban Heat Island (UHI)

7. Exercise/Recreation - Green Space Active RecreationPassive Recreation Obesity a major health issue

8. Without irrigation many sites do not deliver positive services during low rainfall/drought

9. To deliver Health Benefits from Green Space (1) Spaces for Exercise 1.Attractive – Healthy, high quality plants 2.Usable and safe – Surface functional 3. Access – 300 to 400 m 4. Area – e.g. 3.0 ha per 1000 residents 5. Reliable – Independent of climate variations such as drought

10. Urban areas and cities can be hot! The Urban Heat Island (UHI) Effect

11. Feb. temps 2009 Av. Deaths 2004-2009 Extra Deaths in 2009 heat wave Reference: Rod Dedman, Vic. Depart of Health. Alternative water supplies for health and wellbeing. Deaths from excess urban heat

12. To deliver Health Benefits from Green Space (2) Spaces for Heat Moderation 1.Full coverage of vegetation – high Leaf Area Index (LAI) 2. Healthy vegetation with high ET rate. 3. Trees are powerful microclimate modifiers

13. Role of Trees – Environmental modification Crop Coefficient: E.g. Strong healthy growth (Kc 0.8), not Survival (Kc 0.4)

14. To achieve cooling ETo – Evapotranspiration Energy partition – Latent Heat ETo Lower air temperature Message: Irrigation is often required to achieve microclimate cooling.

15. Microclimate Cooling High Crop Coefficients (Kc) required

16. Security of Water Supply Strategies Work with constraints (e.g. limited volumes or times, reduced pressure) of supply from reticulation mains Water source independent of climate conditions (e.g. recycled or desalination) Storage size to meet risks Integrated approach

17. Stormwater Harvesting – Meeting irrigation demand Storage

18. Storage Sizing and Reliability of Supply Increasing storage capacity & $s Increasing reliability of supply % Diminishing returns

19. Storage Sizing and Reliability of Supply Increasing storage capacity & $s Increasing reliability of supply Use potable water to provide security of supply during drought % 80 60 100

20. Storage Sizing for Reliability of Supply Balancing increasing cost of storage and value of the benefits and/or potable water savings delivered by the system. *Important to note that the value of the services will be greatest at the time that the supply is likely to fail. Is 75% or 80% reliability adequate?

21. Water Quality What are the risks? 1. Chemical 2. Physical 3. Biological

22. Key Water Quality Parameters Chemical  pH (Acid/Basic)  Dissolved elements E.g. Sodium  Heavy metals E.g. Mercury, Zinc Physical Suspended solids – irrigation blockages Microbiological – Human health & Plant health Viruses, Bacteria - Pathogens Human: e.g E. coli Plant: Phytophthora spp.

23. Irrigation Water Quality Parameters ParameterUnit Acidity/BasicpH Salinity Electro Conductivity (EC) Total Dissolved Solids (TDS) dS/m mg/L; ppm Sodium Adsorption Ratio (SAR)SAR units Total Suspended Solids (TSS)mg/L EG. Sodium, Chloride, Phosphorous, Nitrogen. e.g. Sodium mg/L Biological/Biochemical Oxygen Demand (BOD) (5day) Dissolved oxygen mg/L Message: Define Water Quality Criteria

24. Risk of Blockage of Drip Emitter Water Parameter UnitLow RiskHigh Risk Acid/alkalinepH< 7.0> 8.0 Suspended solids (TSS) mg/L< 50  100 Salinity TDS/EC mg/L< 500  2000 Iron, Bicarbonates Source: Harris (2006) DPI, Qld.

25. Stormwater Storages What are the risks? 1. Human health 2. System effectiveness and functioning Strategies to minimise the risks a) System design (e.g. treatment systems) b) Water quality standards c) Regular monitoring

26. Water Quality Considerations Characteristics of catchment – Urban or industrial. Hydrocarbons, Oil spills, Chemical spills, Plant health chemicals Frequency of testing of stormwater E.g. 2 weeks Time for some tests e.g. pathogen to be done may be 2 weeks. Well after the event.

27. Efficient Use of Water 1.Water Use Efficiency (WUE) and 2. Irrigation Efficiency (IE)

28. Efficiency - Essential component of Green Space Irrigation How do you encourage or foster efficiency? Irrigation design standards. E.g. IAL Urban Best Management Practice In-house Irrigation standards * Specify regular performance evaluation. Message: Strongly endorsed irrigation standards

29. OVERALL IRRIGATION EFFICIENCY APPLICATION EFFICIENCY SCHEDULING /WATER MGT. EFFICIENCY Message: Both need to be high to achieve High Overall Efficiency Irrigation Efficiency

30. Green Space Messages 1.Define site outcomes and services E.g. Exercise? Cooling? 2. Secure water source to deliver benefits during low rainfall/drought. 3. Set water quality standards for sustainable use. Monitor both (a) water and (b) soil.

31. Green Space Messages 4. WSUD systems need monitoring and maintenance. Resource provision. 5. Apply design, installation and management standards that promote efficiency. 6. Irrigation zoning to allow separate watering of areas with different demand. E.g. Trees separate to grass/lawn. Keep trees healthy.

32. Green Space (Irrigation) Health Community Wellbeing