Appendix J - Water Supply and Wastewater Servicing Report

Lutheran Services                                                                                 Page 8 of 15
PF80 - Cooroy Care Farm
24 May 2018                                                                                 Ref. No. 2017.0616




       From February 2017, the requirements apply to Queensland Health hospitals with inpatients,
       Queensland Health operated residential aged care facilities and licenced private health facilities,
       however, the requirements are expected to be extended to the private residential aged care
       sector at a later date, following consultation with the sector.
       Under the new regulations, facilities will be required to:
       ▪ Develop a water risk management plan;
       ▪ Ensure the water risk management plan is complied with;
       ▪ Notify the Department of Health if Legionella is detected; and
       ▪ Submit periodic reports summarising the results of Legionella tests.
       These requirements will apply regardless of whether the facility has a private supply or is
       connected to a mains service.


       3.4           Roofwater Water Balance
       A detailed water balance model has been developed to assess the potential for roofwater to meet
       the requirements of the development.
       An indication of historical site rainfall is provided in Table 5.

Table 5 Rainfall Data – Black Mountain

 Parameter                                  Value
 Annual Average Rainfall                    1,585 mm
 Range (5%ile – 95%ile)                     975 – 2,287 mm
                                            (-38% to +46% of average)
 Monthly Average Rainfall                   Average 138 mm
                                            Range 58 mm (Sept) to 232 mm (Feb)


       The daily roofwater model was developed as follows:
       ▪ 100 years of daily rainfall data was used (01/01/1917 to 31/12/2016 from the Bureau of
         Meteorology’s Data Drill);
       ▪ Effective connected roof area = 90% of total;
       ▪ Initial rainfall losses 2mm;
       ▪ Average demand as per Table 4; varied +/- 25% seasonally;
       ▪ It is assumed that tanks will be provided at each building pumping to a central raw water
         storage and water treatment plant.
       The results of the modelling are shown in Figure 5 and summarised in Table 6. The analysis
       indicates that a total of approximately 850 kL of roofwater storage will be required to supply all but
       1,000 kL/year of demand on average (ie 85% reliability). Note that this is an average value and
       the actual shortfall is expected to vary between zero and 3.2 ML/yr depending on seasonal
       rainfall.