Tamborine Mountain Boring for Facts on Water Rainfall, water storage and useage 29 th May 2005

1. Tamborine Mountain Boring for Facts on Water Rainfall, water storage and useage 29th May 2005 Tamborine Mountain - 2002 Aerial Photo Ian Shephard BE MEngSc 94 Bartle Road Mount Tamborine 07 55450481 isheps@tpg.com.au

2. Preamble The following PowerPoint presentation was prepared for the Water Forum on the 29th May 2005 sponsored by Tamborine Mountain Landcare. The analysis was based on the best available data and necessarily relies on some estimates based on other regions when Tamborine Mountain site specific data was not available in the public domain. Conservative estimates were adopted to ensure that the results of the study were robust.

3. The Earth’s Water Resource The Earth’s water exists in the following locations: oceans 97.5% (saltwater) glaciers and ice caps 2% atmosphere 0.001% Only 2.5 per cent of the world's water is fresh, and the vast majority of that is frozen in glaciers and icecaps. Less than 1% of water is in the groundwater, lakes, and rivers All told, less than 0.3 per cent of the planet's fresh water is in the lakes and rivers. ENERGY EFFICIENT SOLUTIONS PTY LTD

4. Australia’s Water Resource Total water use 24,000,000 Ml / year • Surface water 19,000,000 Ml / year • Ground water 5,000,000 Ml / year • Irrigation 75 % • Urban / Industrial 20% • Rural 5% • Equivalent to 1.2 Ml / person / year

5. Australia’s Water Resource - Rainfall

6. Australia’s Water Resource - Groundwater

7. In a typical Australian household people use more than 270 litres of water a day. Gardening is responsible for up to half of the water used each day. Flushing toilets uses about another quarter. The SEQ Infrastructure Plan states that the current average residential water use across SEQ of 300 litres per day per person is to be reduced to 230 litres per day per person by 2020

8. Tamborine’s Water Resources • No reticulated water supply • No significant dams or weirs • No run of river supply Tamborine relies on :- • Rainfall / Household Rain Water tanks • Ground Water Bores

9. Albert River

10. Tamborine Mountain Rainfall Isohyets Ref. M Russell

11. Fern Street Monthly Rainfall Ref. Aust BOM

12. The Occurrence of Groundwater in South East Queensland Ref. DNR

13. Mt Warning Volcano 23 million years ago RL 2000 m Tamborine Mountain RL 500 / 580 m Basalt cap ~100 to 200 m Ref. W Willmott

14. RL to base of Basalt Cap Western edge ~RL 300 Eagle Heights ~RL 400 Golf Course ~RL 450 ~RL 500 Ref. W Willmott

15. Ref. W Willmott

16. Ref. W Willmott

17. Basalt Plateau Comparison Atherton Tamborine Recharge Area (Km**2) 100 25 Elevation RL (m) 600/1000 500/580 Average Annual Rain (mm) 1650 1550 Annual Pan Evaporation (mm) 1800 1600 Annual Evapotranspiration (mm) 1000 750 Basalt Cap Thickness (m) 50 to100 100 to 200 Conductivity (mS/cm) 0.1 to 0.2 0.1 to 0.2 Seasonal Water Table (m) 6 ? Average Annual Recharge (%) 15% to 33% ? Suggests Ground Water Recharge for Tamborine of at least 15% Ref. CSIRO report Atherton Tablelands

19. Tamborine MountainPopulation and HousesCurrent Population ~ 6500Current Residences ~ 2750Total existing FH lots > 3600Potential Population ~ 9000Potential No. Houses ~ 3750

20. Tamborine MountainGroundwater Recharge AreaLocality Total Area 3300 haArea above 450m 2900 ha (7000 acres)Plateau Area 1800 haAdopt Recharge Area ~ 2500 ha ~ 6000 acres

21. Tamborine MountainAgriculture Irrigation AreasDCP Planning study 1997 Total area of 210 ha 25% utilising irrigationHarrison Grierson Report 2001 Total area of 170 ha Adopt agriculture area ~ 200 ha ~ 500 acres

22. Domestic Water UseHousehold and Gardening Current Population 6500 • Water Use @ 300 l/d/p and 150 l/d/p • Annual Use 6500*300*365 = 710 Ml / year • Annual Use 6500*150*365 = 355 Ml / year Future Population 9000 • Water Use @ 230 l/d/p and 150 l/d/p • Annual Use 9000*230*365 = 755 Ml / year • Annual Use 9000*150*365 = 500 Ml / year Note. Gardening is responsible for up to half of the water used each day

23. Domestic Water UseHousehold and Gardening Water Use on the previous slide is a conservative figure for Tamborine and is based on the current and planned future SEQ daily useage from reticulated water supply and includes gardening. Tamborine Water Use from household water tanks would generally be expected to be around half the general SEQ useage ( 150 l/d/p ) This lower useage rate HAS NOT BEEN USED for this water balance. Adopt conservative useage of 750 Ml / year

24. Household Rain Water tanks • Current Population 6500 / Houses 2750 • 2750 Houses / 250 sq m / 1.55 m rain / 33% yield • Annual secure rain water supply 350 Ml / year • Future Population 9000 / Houses 3750 • 3750 Houses / 250 sq. m /1.55 m rain / 33% yield • Annual secure rain water supply 500 Ml / year • Adopt conservative supply of 500 Ml / year

25. Rainwater Tank Sizing • Volume of water needed • Number of people • Average consumption per person • Range of uses • Conservation measures • Rainfall records • Area of roof catchment • Security of supply ( back up source ?) • Determine Tank Size

27. Beaudesert Shire Council Computer Simulation Model - INPUT

28. Beaudesert Shire Council – Model Results

29. Beaudesert Shire Council – Model Results

33. 2004 Rainfall at 94 Bartle Road Fern Street Monthly Rainfall Ref. Aust BOM

34. Beaudesert Shire Council – Model Results

35. Bore Water Supply • Total of 800 plus bores currently on Tamborine Mountain • Average 60 m deep (200 feet) • Some as deep as 150m (500 feet) • Not all bores were successful • Not all bores are currently active • Approx. 100 bores used predominantly for agriculture irrigation, domestic water carriers and off mountain water supply • Approx. 500 bores used predominantly for supplementing domestic rain water tanks and for gardens.

36. Bore Water Supply - Agriculture 100 bores used predominantly for agriculture irrigation and water supply • Typical capacity 1litre / second (800 gph) • Typical capacity factor 17% maximum ( 4 hr / day) • Total bore water pumped from 100 bores 100*3600*24*365*0.17 = 500 Ml / year

37. Bore Water Supply – Domestic & Gardens 500 bores used predominantly to supplement domestic rain water tanks and for gardens. • Typical capacity 0.275 litre / second (220 gph) • Typical capacity factor 5% maximum (1+ hr / day) • Total bore water pumped from 500 bores 500*0.275*3600*24*365*0.05 = 220 Ml / year

38. Bore Water for Off Tamborine Supply • Hartley Road 20 / week • Holt Road 6 / week • Curtis Road 6 / week • Power Parade 2 / week • Bateke Road 1 / week • St. Bernard Street (2@1/2) 1 / week • Siganto Street ? • Prospect Street ? Average of 36 loads per week 36 * 52 * 28000 litre = 50 Ml / year

39. Bore Water for Domestic Carriers 3 Domestic Water Carriers • Operate 6+ days per week • Up to 12 loads per day typical • Typical load 12000 litre • Do not operate at full capacity all year • Adopt 8 months (April – November) 3 * 6 * 12 * 12000 litre * 35 weeks = 90 Ml / year

40. Agriculture Irrigation Water Use • Agriculture area of 200 ha • 33 % of area utilising irrigation • 500 mm of irrigation water per year • Equivalent to 10 mm every week • Equivalent to 5 Ml / ha / year Total Agriculture Irrigation useage 330 Ml / year

41. Domestic Bore Water UseSupplementing rain water tank supply • Assume 500 active domestic bores • Assume 3 tank refills per house • 50 Ml / year • 500 mm of garden water per year • Equivalent to 10 mm every week • Assume Garden / lawn area of 40 ha • 200 Ml / year Total domestic bore water useage 250 Ml / year

42. Estimated Water Balance Tamborine Mtn. 1550 mm rainfall (2500 ha) 38 750 Ml 100% 750 mm evapotranspiration 18 750 Ml 48.5% Surface run-off to creeks 13 650 Ml 35% 15% groundwater recharge 5 800 Ml 15% 15% recharge is an estimate based on the Atherton Study in the absense of data specific to Mount Tamborine Household rain water tanks >500 Ml >1.3%

43. Estimated Groundwater Balance Tamborine Mountain 15% groundwater recharge 5 800 Ml 100% 15% recharge is an estimate based on the Atherton Study in the absence of data specific to Mount Tamborine Exported off Tamborine 50 Ml 0.9% Bore water - domestic carriers 90 Ml 1.5% Bore water - agriculture irrigation 330 Ml 5.7% Bore water - domestic & gardens 250 Ml 4.3% Total groundwater extraction 720 Ml 12.5% Net groundwater extraction approx. 10%

44. Estimated Groundwater Storage Tamborine Mountain • Basalt Cap adopt 150m thick over 2500 ha • Basalt effective porosity typically 3% to 50% • Basalt effective porosity Atherton 5% to 20% • Adopt effective porosity 5% for Tamborine Basalts • Groundwater storage in Basalts • 150m * 2500ha * 5% = 187 500 Ml • Equivalent to 32 years of average annual recharge • Equivalent to 260 years of current annual extraction

45. Boring for Facts on Water • Rain water tanks generally meet household demands supplemented with domestic bore water supply or bore water delivery • Agriculture irrigation demands are decreasing • Garden water supply demands are increasing • Bore water supply for supplementing domestic and off Mount Tamborine uses are sustainable • Low water demand native gardens should be encouraged • Conservation of water should be encouraged

46. Boring for Facts on WaterWhere to now? • Have good rainfall data • No data on stream flows • May need stream flow monitoring • Little data on bores • Need background watertable monitoring • Need Tamborine specific data on ground water recharge to confirm adopted recharge rate of 15% • Need data on existing bore useage to confirm irrigation, supplementary domestic and gardening demands