Johnsons Waterhole Monitoring Report (2013-16) 1

Water for Nature Environmental Watering

Site Monitoring Report by Dr Anne Jensen

Johnsons Waterhole, South Australian Riverland July 2013 to June 2016

Nature Foundation SA is a not-for-profit nature charity that works to Save, Protect and Restore South Australia's natural biodiversity. Since 2008 one of our flagship programs, Water for Nature, has been delivering environmental water along the Murray River to help reduce the loss and stress to ecosystems and habitats caused by river regulation and drought. Over the last three years, our Water for Nature program has worked with 200 volunteers to deliver 4.56 gigalitres of environmental water to more than 35 wetland and floodplain sites along the Murray River. Healthy wetland and floodplain environments are important for environmental, economic, cultural and social reasons, providing an optimal environment for flora and fauna, improved water quality for human consumption and agricultural use, and opportunities for recreation and tourism. We work with private landholders, irrigators, community groups & local government on smaller sites to deliver environmental water, complementing larger government watering projects. Nature Foundation SA also works closely with the Commonwealth Environmental Water Holder to deliver environmental water.

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Water For Nature Environmental Watering Site Monitoring Report Site name Johnsons Waterhole, South Australian Riverland Reporting period

July 2013 to June 2016

Date prepared July 2016

Location

Johnsons Waterhole is located adjacent to Ral Ral Creek, approximately 5 km north-west of Renmark

Contact Name NFSA Water For Nature Program Manager Natalie Stalenberg RIT: Kate Strachan

Water Provider Commonwealth Environmental Water Holder allocation to NFSA

Partners Renmark Irrigation Trust (RIT), District Council of Renmark Paringa (DCRP), Renmark to Border LAP, local landholder & irrigator Kate Strachan

Aim of watering project

The environmental watering project aims to create inundation in the wetland of 10-12 weeks from late October, with natural draw-down by evaporation over summer. This would mimic historic natural conditions and allow completion of life cycles in frogs, water plants and waterbirds.

Regional Planning Context

Siebentritt et al. (2013) ‘Reviving the Ral Ral Floodplain: An Options Analysis Paper’ included a recommendation for watering Johnsons Waterhole and connecting the flow path from Ral Ral Creek to Bookmark Creek

Renmark

JohnsonsWaterhole

River Murray

Ral Ral Creek

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Key objectives Environmental watering at this site has the following objectives: 1. provide and maintain seasonal habitat to support aquatic plants, yabbies and frogs 2. extend feeding habitat for waterbirds and increase the abundance and diversity of

waterbirds at the waterhole 3. improve soil moisture levels to enhance understory cover and provide optimum

condition for the survival of trees and riparian plants on the wetland fringe

Site Description

Johnsons Waterhole is located adjacent to Ral Ral Creek, a permanent floodplain anabranch approximately 5 km north-west of Renmark. It is approximately 570 km from the Murray mouth. It is a key temporary wetland site on the 610 ha Ral Ral floodplain, opposite the Murray River National Park (Bulyong Island) and is adjacent to the Renmark Irrigation Area. While the waterhole itself is only 4 ha, it is a key element in the flood-runner which links Ral Ral Creek to Bookmark Creek across the floodplain when river flows exceed 50,000 ML/d. The flood-runner inlet is located south of the Goolwa Street boat ramp, and the flow path continues south-east through the waterhole to link up with Bookmark Creek close to Ral Ral Avenue. This section of the Ral Ral floodplain lies between Ral Ral Creek and the Renmark Irrigation Area and is managed by the District Council of Renmark Paringa. The Ral Ral floodplain north of the Goolwa Street boat ramp is managed by Renmark Irrigation Trust. The floodplain once had river red gums and lignum along minor flow paths, scattered black box trees over saltbush shrubland and thriving samphire shrubland. The inlet to the waterhole starts to flow at 35,000 ML/d. The waterhole filled nearly every spring and persisted for several months, but reduced flooding and extended drought have caused extensive damage through lack of freshwater flows and the impacts of highly saline regional groundwater. A line of stark dead red gum skeletons show where floodplain communities and the waterhole once thrived.

Habitat Johnsons Waterhole holds water for 2-3 months once filled, indicating sufficient clay in the bed to create water-holding capacity. Locals report a healthy yabby population when the waterhole has filled previously in floods, and waterbirds such as avocets have been observed feeding in the remnant pool. In spite of the lack of riparian vegetation, there are multiple roosting trees with hollows, nearby healthy black box woodland with understory plants, and samphire shrubland surrounding the wetland, providing varied riparian habitats to supplement the aquatic habitat when the wetland is filled.

Watering History 2013-16

Watering commenced in November 2013 with the aim of delivering 150 ML over 3 years. The purpose is to create temporary wetland conditions starting in late spring and persisting into summer. More than 300 ML has been delivered 2013-2016 in three seasonal waterings. 103.9 ML was delivered in two pulses in the period November to March 2013-14. 91.4 ML was delivered to the wetland in October 2014-15 to provide a second seasonal filling, including a top-up in March 2015. A further 116.5 ML was delivered from July to October 2015 to continue to support development of aquatic plants and provide food sources for waterbirds. Native riparian and low shrub species were planted on the edge of the wetland in July 2014, and watered by sprinkler (2ML) in October 2014.

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Water Source NFSA allocation from Commonwealth environmental water 2013-2016; delivered by Renmark Paringa District Council, NFSA pumps and RIT infrastructure

Event details 2013-14 Initial fill of 58.6ML in November 2013 using DC Renmark Paringa pump and NFSA pump, second fill 45.3 ML in March 2014 using NFSA pump (total 103.9 ML) 2014-15 Fill of 91.4 ML in October 2014, using RIT infrastructure, operated by Kate Strachan 2015-16 116.5 ML fill in October 2015, using RIT infrastructure, operated by Kate Strachan Maximum area inundated (ha) Estimated area 8 ha, including overflow Duration of the environmental watering project (2013-16) Three seasonal fillings, in late spring through summer

Figure 1 Johnsons Waterhole filling in October-November 2014, showing extent of inundation in connected flow paths upstream and downstream of the main wetland (Photo: Teagan McKillop; aerial photo: DEWNR 2014)

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Annual Observations against key objectives (including species of conservation significance (state or Commonwealth listed threatened species, or listed migratory species) observed at the site, any breeding of frogs, birds or other prominent species observed at the site and details of any observable responses in vegetation, such as improved vigour or significant new growth)

2013-14 (report by Irene Wegener, DEWNR) Initially relatively low numbers of birds of 20 species used the waterhole for foraging and resting. There was good functional group diversity, with dabbling duck, diving ducks, waders, piscivores, and herbivores, indicating the availability of diverse habitats and food sources. The largest numbers (up to 200) were grey teal, mountain duck and hardhead. A range of terrestrial birds were also observed, including superb fairy wrens, and red-rumped parrots nested. Frogs recorded included eastern banjo frog, spotted marsh frog, Peron’s tree frog, southern bell frog and long-thumbed frog. Tadpoles of Peron’s tree frog were observed but it was not clear if successful recruitment (survival to maturity) occurred as a result of watering. 2014-15 (report by Teagan McKillop, RB LAP) Multiple bird species with conservation status EPBC-Migratory were observed, including Black-Fronted Dotterel, Australian Shelduck, Black-Winged Stilt, Red-Kneed Dotterel and Red-Necked Avocet. No rare or threatened species were sighted. A significant submergent aquatic community developed in early 2015, with water milfoil (Myriophyllum salsugineum), ribbonweed (Vallisneria americana), Ruppia spp. and filamentous green algae. Monitoring of water table height, groundwater salinity and surface water salinity was carried out in 2014-15 by Teagan McKillop of the Renmark to Border LAP (see observations below and graphs attached). These findings addressed concerns about potential salinization of surrounding areas on the floodplain. There was evidence that a freshwater lens developed overlying saline regional groundwater. 2015-16 (observations by Kate Strachan and Anne Jensen) During 2015-16, over 200 black swans were observed using the wetland for feeding and resting. Other species included grey teal, white ibis, straw-necked ibis, mountain duck, little grebes and masked lapwings. A pelican was observed fishing in the wetland, indicating that fish can survive the filling process via pipelines. Most planted riparian native species survived well, maintained by watering. Bulrush (Typha domingensis) appeared in riparian zones from September 2015, similar to the riparian fringe observed in historic photographs of the wetland from the 1950s.

Future Watering Continue late spring-early summer fillings 3 years in 5, taking into account any natural floods or extended drought periods, and ecological condition. Note that management of this site has been handed over to the Renmark Irrigation Trust from 2016-17.

Figure 2 Johnsons Waterhole filling in November 2013 (Photo: Peter Hunter)

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Figure 3 Views of Johnsons Waterhole, showing bulrush riparian fringe in 1950s (photo: Dud Foweraker); Google Earth image in spring 2015; views of watered wetland and fringes (photos: Kate Strachan)

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Figure 4 Johnsons Waterhole dry in July 2013: looking downstream along inlet channel towards waterhole; red gum sapling surviving at northern end of waterhole near inlet channel; dry waterhole looking upstream from western viewpoint toward inlet point; dry waterhole looking downstream from western viewpoint towards outlet point; dry waterhole looking across from western view point to line of dead red gums on riparian edge (2 photos) (photos: Anne Jensen)

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Figure 5 Johnsons Waterhole filled in October 2014: looking downstream along inlet channel towards waterhole; nardoo growing in flooded inlet channel; filled waterhole and riparian zone; filled waterhole looking upstream from western viewpoint toward inlet point; filled waterhole looking downstream from western viewpoint towards outlet point; filled waterhole looking across from western view point to line of dead red gums on riparian edge (photos: Anne Jensen)

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Figure 6 Johnsons Waterhole receding in May 2015: receding waterhole looking upstream from western viewpoint toward inlet point; receding waterhole looking downstream from western viewpoint towards outlet point (3 photos), red colour is stranded azolla fern, which will act as mulch; receding waterhole looking across riparian zone from western view point to line of dead red gums on riparian edge, showing large number of black swans (2 photos) (photos: Anne Jensen)

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Figure 7 Johnsons Waterhole receding in October 2015: growth of lignum and red gum seedlings in inlet channel, looking downstream to waterhole; receding waterhole looking upstream from western viewpoint toward inlet point; receding waterhole looking across riparian zone from western view point to line of dead red gums on riparian edge, showing large number of black swans and extensive algal mats (3 photos); receding waterhole looking downstream from western viewpoint towards outlet point (photos: Anne Jensen)

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Figure 8 Johnsons Waterhole receding in March 2016: red gum sapling thriving near inlet channel; receding waterhole looking downstream from inlet point, showing variety of waterbirds using habitat (3 photos); receding waterhole at western viewpoint; receding waterhole looking across riparian zone from western view point to line of dead red gums on riparian edge, showing large number of black swans and riparian growth (photos: Anne & Bjarne Jensen)