Despite the massive 24 inch pumps drinking upstream, some of the Murray-Darling water does reach the sea at the quiet town of Goolwa, in South Australia, through the 86-year-old River Murray Barrages.
My first visit to the Coorong and the Murray Mouth was many years ago, but a recent visit opened my eyes to the wonderful new system of fishways that now allow fish to move from the ocean right up to the Hume Dam, a distance of 2225 kilometres.
Fishways, also known as fish ladders, are structures that allow fish to navigate through obstacles in rivers and creeks.
Fishways create slower water velocity, eddies and resting pools suitable for fish migration.
Water flowing through the barrage fishways attracts fish to the entrances.
Once inside, fish of various sizes move through the fishway and exit on the other side of the 26 man-made locks, weirs, and barrages on the River Murray.
The installation of fishways is seen as a way of recovering the precipitous loss of native fish species in the Murray, since 30 of the 50-odd native fish species of the Murray-Darling river system are marine species or are diadromous, spending part of their lives in fresh water and part in the sea.
The congolli, for example, resides in freshwater habitats as an adult, but spawns in the ocean. As such, the ability of adults to migrate from freshwater to marine habitats to spawn and then for juveniles to migrate upstream into freshwater habitats is fundamental for the persistence of populations of this species.
The new fishways will help protect threatened fish species by allowing them to move between important habitats and ensure significant species and populations of fish are retained.