South East Drains - a key to restoring the Coorong, and Lake Albert should survive.
There are two actions needed for restoration is to improve tidal flow into and from the North Lagoon by clearing of silt from Pelican Point to the mouth area (by tidal flow from the lakes), draining S.E. surface storm water, into South Lagoon via Salt Creek.
The Blackford Drain carries water from west of Avenue, east of Robe and delivers it to sea just north Kingston. Drain ‘L’ drains to sea at Robe, and carries water from as far away as Bool Lagoon to the east and near Millicent to the south east. Many of these drains are interconnected, linked through the eastern division diversion drain and draining into Lake George, or through the Mount Hope drain through to the sea at Robe.
If this drainage system were modified to carry surface water northward, between the ranges it could be delivered into the Coorong’s south lagoon. When the freshwater injection into the Coorong is of a volume greater than evaporation loss from the south lagoon, the salinity front will move up and down the south lagoon with the seasons.
During periods of highest flow during winter there would be lower salinity in the south lagoon, and during summer salinity would increase with more tidal water entering from north lagoon. This restoration action would provide for Coorong conditions very closely approaching those existing before we came along. In fact, we are better able to restore the Coorong as it is now (because it has not been reliant on the Murray River) than we can ever hope for to achieve with the Murray River itself.
Lake Albert has always been a ‘dependent’ on the side of Lake Alexandrina. It did have some injection of fresh seasonally from the vicinity of Wallowa Swamp in the NE of Lake Albert. Rise and falls in levels, and wind surges from one side of Lake Alexandrina to the other, would have provided the flow through Narrung Narrows to keep that channel open.
There should be enough surface water available in the drains so that it may not be necessary to store water at the Martin’s Washpool and let it go as a slug into Salt Creek. The seasonal rains should provide the salinity wax and wane required, and if drain incorporation is widespread enough, there should be adequate volume.