Tuesday, February 23, 2010

Dirty water.

Within two months of the marina opening and it was producing fowl water. One corner of the marina basin does not flush properly. The water in that corner is already red. It’s as if the excavated faces of the marina basin has pierced a flow of iron colour underground water to flow into the marina.
This colouring makes the water opaque. At low tide the water in the marina basin is below sea level, like a rock pool stranded by the tide. The opaque, stranded water heats up. On the 5 February at low tide the water temperature was 4 degree hotter in the marina basin than at the boat ramp, 500 metres away.
Worse is the overall water quality and the stuff that’s growing on the marina piers and boats below the water line. Petro-chemical slicks stick around for days and some weird looking stuff grows on the surface. The algae looking stuff on the piers and boats feels like jelly but alive and it’s growing very well.
Before the marina the estuary water was never this colour, the area did not amass petro-chemical spills, did not rapidly grow red / brown stuff. The opaque colouring, the petro-chemical build up and the algae (?) growth are environmental affects from the marina being constructed in that place.
Not enough tidal flushing is part of the problem. What did the Environment Court say about this matter when assessing the environmental affects?

Decision No. A 173 / 2005.
[44] Ms Sheffield went on to suggest that tidal flushing of the marina would not occur over a two day-day tidal cycle, contrary to evidence adduced for the society. Mr Caldwell stated in response that, in the light of calculations undertaken with the flushing rate, based upon a marina water depth of approximately 4.0m and a neap tidal range of greater than 1m, “ the ebb and flow during the tidal cycle and the mixing that that(sic)induces in the marina will be sufficient to ‘turn over’ the complete volume of the marina in two days (four tide cycles)” He went on to explain the reasoning supporting his view, and, having considered it against the concerns raised by Ms Sheffield, we accept that poor quality due to lack of flushing is not likely to be an issue on the basis of the works proposed in creating the marina basin and channel and maintenance dredging intended.

Good guess in theory but the Environment Court has got the reality wrong.