2 Renmark to border LAP area assessment - EPA - Sa.gov.au

River Murray and Lower Lakes catchment risk assessment for water quality: Results and management options
Risks to recreational use
Figure 7.5 is the key map for risks to the raw water supply environmental value in the GW & CD LAP
areas. The attached DVD has individual maps numbered according to the key map.
Frequencies of identified risks to recreational values for the various water quality stressors are
summarised in Table 7.3. The highest frequency of risks was for pathogens followed by hydrocarbons,
turbidity and nutrients. The majority of these risks (149) were assessed as low level although a large
number (103) of moderate-level risks were identified. No high or very high risks were identified.
Table 7.3 Frequency of risks to recreational use, GW & CD LAP areas
PA—pathogens; NU—nutrients; TU—turbidity; HY—hydrocarbons
Table 7.4 lists the recreational risks identified in this LAP area which are discussed in more detail below
in relation to each stressor.
Pathogens
Septic tanks (eg north side of Hindmarsh Island, Mundoo channel, Clayton West, Meningie shacks)
presented a moderate risk through leakage (exacerbated by overloading or other system failures). The
north side of Hindmarsh Island could be a priority for mitigation given that there is high-use recreation in
this area and flow/flushing restrictions imposed by the Goolwa barrage. The Milang south shores shacks
are being connected to STEDS but this was not fully operational (still some septic tank soakage trench
risks) so a moderate risk was assigned.
Vessel mooring areas and marinas were in general assigned a moderate risk ranking due to the likelihood
of greywater and blackwater discharges. A cumulative risk may be present from vessels and marinas in
and near Goolwa. The Marina, Hindmarsh Island was given a low risk ranking due to presence of a vessel
waste disposal station and no vessels with live-aboard accommodation that discharge waste (there are
only a few live-aboard vessels and the waste from these is pumped to the marina treatment plant).
There are much fewer live-aboard vessels/houseboats in the Coorong and Lower Lakes area than on the
river but there is a large amount of boating activity (over 1400 boats mainly fishing, sailing and ski,
Helicon Consulting 2003). Many of these types of vessels have only portable toilet systems (higher
potential for illegal discharge) and there are currently insufficient land-based facilities for people to
empty these toilets. Potential accidental spillage at the Goolwa river vessel waste disposal station
(connected to the Goolwa STEDS) was also given a moderate risk and community concern was raised
about its exposed location.
210
Stressor
Risk PA NU TU HY Total
Low 21 41 22 65 149
Moderate 61 7 35 0 103
High 0 0 0 0 0
Very high 0 0 0 0 0
Total 82 48 57 65 252