Point Sturt and Districts Landcare Group Inc: Milang Jetty
Bottle number: 111
About the water
Collected at: Near the end of the Jetty at Milang, Lake Alexandrina, South Australia
E: 316279, N: 6079776, Zone 54
Collected by: Point Sturt and Districts Landcare Group Inc.
Milang is with-in the Landcare Group district and the current state of Lake Alexandrina at Milang (and the whole of Lake Alexandrina and Albert) should be a national diaster area.
|Turbidity:||NTU ~ 40|
|Nitrates:||less than 0.5mg/L|
The township of Milang and the surrounding areas are devastated by the current state of Lake Alexandrina. Milang is suffering as a result of the condition of Lake Alexandrina.
ACT Waterwatch says:
The samples from Bottle 110 and Bottle 111 (like others in this batch) reflect the upper estuarine nature of Milang and the mouth of the Angas as the many years of low flows and saline ground-water input have quietly affected the system. I'm sure the Angas in Strathalbyn is quite high in pH, but relatively low in electrical conductivity and much of that coming from the limestone and phyllite in the catchment at the top of the Mt Barker part of the Mount Lofty Ranges. If, as the sample indicates, flow in the mouth of the Angas is tidal, then the salinity is equivalent to that of Lake Alexandrina, which has become steadily more saline in recent years. This is a product of the combined effects of low flows in both the Murray and the Darling, saline seepage in the ground water of the lower Murray from at least Murray Bridge and backflow mixing from the Coorong as the Murray Mouth/ Younghusband Peninsula has been closed more often than not for at least ten years. The water is probably salty to taste and not wonderful on the citrus but ...
The turbidity reflects the level of suspended material that comes from both the lake bottom sediments, which are marl-like, and the coloured sediments of the lower Murray (and Angas) catchment. The moderately high phosphate load may be an indication of prolonged agricultural use of the flood plains. Lake Alexandrina has had cyanobacterial blooms in the recent past, and supports plenty of biological activity
About the site
Only the very end of the Jetty is in the Lake, large areas of the Lake bed are dry and the current shore-line is (in some area) 500m from the original shore-line.
Near end of Milang Jetty, focus of riverboat use from late 19th century. Only the last few metres of the 60 metre long jetty are now in water.
Lake Alexandrina was maintained at between 0.75 AHD and 0.85 AHD since completion of Goolwa Barrages in 1940s.
At time of sampling it had fallen to (minus) -0.8 AHD and shoreline had retreated about 150m and in some places up to 500m.
What's going on:
Bioremediation project underway around shoreline of Lake Alexandrina, under direction of SA Government.
Includes planting of natural and exotic grasses, intended to limit wind erosion and return carbon, and fencing of shoreline to prevent stock incursions after water returns to Lake Alexandrina.
Milang Primary School student have, since 2007, undertaken a rescue effort for long-necked tortoises with massive encrustations of marine bristle worms, resulting from increase in salinity in Lake Alexandrina.
Monitoring of water levels, salinity and ph levels.