000A88A4.12B.tif · 132003.221037

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The AQUALM analysis compared pollutant exports and concentrations for the existing site
(modelled as “forest”), with the proposed development (modelled as “Rural”) with and without
road filter strips. Preliminary simulations indicated that the volume of runoff for the developed
scenario was within acceptable limits; the annual volumetric runoff coefficient (AVRC) for the
developed site was 0.29 compared to the value of 0.24 given in the Brisbane City Council
Guidelines.

The results are summarised in Table 7.3.1, East Visitor Precinct - Summary of Results of
AQUALM Analysis.

Table 7.3.1 : East Visitor Precinct - Summary of Results of AQUALM Analysis

 

 

 

 

 

 

 

 

 

 

 

 

 

Median Existing 1.6 0.35 0.01
Pollutant
Concentrations Post-development no 5.0 0.73 0.05
(mg/L) treatment
Post-development with 2.9 0.58 0.04
treatment
80%iie Pollutant Existing 2.3 0.36 0.04
Concentrations
(mg/L) Post-development no 5.0 0.73 0.05
treatment
Posi-development with 4.3 0.68 0.05
treatment
Poilutant Existing 40 1.2 0.05
Exports
(kg/halyr) Post-development no 102 6.0 0.69
treatment
Post-development with 53 4.0 0.46
treatment

 

 

 

 

 

There is good agreement with the pollutant exports (expressed as kg/ha/yr) for the post
developed scenario with no treatment and the Brisbane City Guidelines for “Rural” lend use
(Total Solids = 107 kg/ha/yr, Total Nitrogen = 5.7 kg/ha/yr, Total Phosphorous = 0.70 kg/ha/yr),
which is considered to validate the model.

The median pollutant concentrations may be compared with Brisbane City Council’s water
quality objectives for freshwater — modified eco-systems (TS = 14mg/L, TN = 0.65mg/L, TP =
0.07mg/L.}. The pollutant concentrations discharged from the filter strips compiy with these water
quality objectives.

The 80%ile pollutant concentrations may be compared with ANZECC/ARMCANZ trigger values
for slightly to moderately modified eco-systems. Trigger values indicate the upper limits for
sustainable pollutant loads on natural eco-systems. For discharges into tropical wetland
systems, these trigger values are-TN-=--+.2mg/L and PP = 0.05mg/L. The AQUALM analysis
demonstrates that the trigger values for TN and TP are not exceeded, which indicates that the
proposed development discharges sustainable poilutant loads into the wetlands.

7.4 West Visitor Precinct

The proposed Wesi Visitor Precinct occupies approximately 4.0ha in a catchment that is to
discharge into a central lake. The proposed lake has a surface area of approximately 2,300m?
and it is located on the site of an existing dam. The lake is to discharge into a wetland located
within the property boundaries.

 

PETRAC LAND HOLDINGS P/L Noosa North Shore Eco-Tourism Portal September 2003
LA7296-03\ReporiiFINAL REPORT - 18Sept03.doc Commercial in Confidence Page 23