9 Lane Cove River 4
Water Quality Ranking: 25 / 43
Data Reliability Ranking:
3/ 43Constituent Council(s):Ku-ring-gai Municipal Council
Constituent stream(s):Rudders Creek
Rainfall Station(s):R07
Sewerage Overflows: 1
Stormwater outlets: 5
Water Quality sampling points: WQ043
Pollution Control Device Numbers: none
Overview:
Landuse:
|
Landuse |
Area (ha) |
% sub-catchment |
% LCR catchment |
|
Open space |
31 |
61 |
1.6 |
|
Residential |
20 |
39 |
0.4 |
|
Business |
0 |
0 |
0 |
|
Industrial |
0 |
0 |
0 |
|
Special Uses |
0 |
0 |
0 |
|
Special Zones |
0 |
0 |
0 |
|
Total |
51 |
100 |
0.6 |
Period of sampling records: August 1989 - July 1992 % wet days: 0
Number of sampling occasions (N): 2
Compliance of key indicators to guidelines - % of time guidelines met under all conditions.
|
Parameter |
|||||||
|
pH |
Faecal Coliforms |
% Diss. Oxygen |
Diss. Solids |
Total P |
Total N |
Ammonia |
Chl. - A |
|
100 |
50 |
0 |
100 |
0 |
50 |
0 |
0 |
Summary: The reliability rating belies the fact that data has been drawn from only 2 occasions. This is why the compliance is only, 0, 50 or 100%. However the results show that water quality is generally poor and sewage and nutrient pollution is evident in the sub-catchment.
Issues: With high levels of sewage pollution and only one designed overflow, the possibility of a large number of exfiltration events from chokes (root blockages) and cracked pipes seems a likely cause of pollution and an area worth investigating.
Knowledge Gaps: It is possible that only one designed overflow exists in such a small catchment but the paucity of water quality data needs to be addressed.
Recommendations: Assessment of the degree of chokes and pipe damage as potential causes of sewer overflows. Obtain more detailed water quality data from AWT where possible.
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