Lower Lakes, Coorong and Murray Mouth

Watering events 2015-16

In spring, 76 GL of The Living Murray (TLM) environmental water was delivered to the Lower Lakes Coorong and Murray Mouth. The water consisted of 56 GL of environmental water returning from the upstream Barmah-Millewa watering action and 20 GL of water that was delivered directly to the South Australian border.

The watering helped to inundate fringing Lower Lakes’ wetlands, provided flow through the barrages and supported the continued operation of the barrage fishways. The watering resulted in frog (including southern bell frog) and fish recruitment, large numbers of nesting colonial waterbirds (more than 1,000 nests) and movement of fish (congoli and common galaxias) through the barrages.

A further 20 GL of environmental water will be delivered to the Lower Lakes in March to maintain water levels.

The Coorong at Lake Alexandrina, where the Murray meets the sea (Goolwa, South Australia). Photo by Arthur Mostead.

Ecological objectives

There are 3 high-level ecological objectives for the Lower Lakes, Coorong and Murray Mouth icon site:

  • an open Murray Mouth
  • more frequent estuarine fish recruitment
  • enhanced migratory wader bird habitat in the Lower Lakes and Coorong.

Underpinning these ecological objectives, there are 16 ecological targets, which were developed to quantify changes in the condition of the site. These targets are detailed in the Lower Lakes, Coorong and Murray Mouth Environmental Water Management Plan.

Engagement of the Ngarrindjeri people, Lower Lakes, Coorong and Murray Mouth (LLCMM)

The Ngarrindjeri people work with the South Australian Department of Environment, Water and Natural Resources (DEWNR) on environmental water planning at the Lower Lakes, Coorong and Murray Mouth (LLCMM) icon site.

One aspect of the program involves Ngarrindjeri people working together with scientists to capture, measure and identify threatened fish in Lake Alexandrina and Albert. This information is used to monitor the ecological health of the fish and their associated habitat while ensuring cultural needs are maintained.

The joint effort to undertake monitoring has been valuable for Ngarrindjeri participants who have learnt skills in data collection, interpretation and fish ecology. Meanwhile, the DEWNR scientists have been able to learn about Ngarrindjeri culture while working at the icon site.

“We look at numbers, we look at data, we don’t have that real connection that I’ve felt the Ngarrindjeri have. They’ve been able to say, ‘we used to fish here, we used to get swan eggs from here’. I’m very tunnel-visioned, I look at aquatic plants. The insight that’s been passed down through the generations is something that I think a lot of scientists can really learn from, because they [Ngarrindjeri] come at it from the opposite direction, where they look at everything as a whole.” — Dr Jason Nichol, Sub-Program Leader Plant Ecology, SARDI Aquatic Sciences (FLOW – Life Giving Lands and Waters TLM DVD)

Sharing knowledge across cultures also occurs in conversations about environmental watering at the LLCMM. The program provides the opportunity for the Ngarrindjeri, DEWNR scientists and the Murray–Darling Basin Authority to get together and talk about where water is needed.

From this collaborative approach, environmental water has been targeted to meet a variety of ecological and cultural objectives. These include providing water to assist fish migration and spawning, providing suitable migratory wader bird habitat, and enhancing germination and recruitment of the vulnerable aquatic plant (Ruppia tuberosa) in the Coorong.

The flowering plant, Ruppia tuberosa is culturally important to the Ngarrindjeri and environmentally important by the DEWNR. Thus South Australia has delivered water aimed at improving the population of flower — an action which met the goals of both groups.

The working relationship between DEWNR and the Ngarrindjeri has grown stronger over the years. This has enabled the Ngarrindjeri to be empowered to lead discussions on how ecological and cultural outcomes can be achieved at their traditional lands and waters.

For more information, visit the South Australian Department of Environment, Water, and Natural Resources website.

Past watering events

Water Year Volume (GL) Outcomes
2014–15 703.9 Managing healthy salinity levels for ruppia, supporting native fresh water and estuarine invertebrates, wetland connectivity and health
2013–14 156 Created suitable conditions for flowering and fruiting of ruppia into early summer
2012–13 239 Maintained connectivity between the lower lakes and estuary, maintained open Murray Mouth, maintained acceptable salinity levels in Lake Alexandrina and provided lateral connectivity with the Murray River channel
2011–12 142.24 Enhanced migratory bird habitat in the Lower Lakes and Coorong, increased frequency of estuarine fish spawning and recruitment and maintained an open Murray Mouth
2010–11 34.3 Enhanced migratory waterbird habitat and allowed greater fish passage across the barrages between the Coorong, Murray Mouth and Lake Alexandrina
2009–10 48.6 Maintained drought refuges for threatened waterbirds and fish species, prevented loss of aquatic vegetation and reduced salinity and the risk of broad scale acidification in Lake Albert