BISCHOFF KRYPONITE 

A MYSTERY NOVEL BY A WARATAH RESIDENT – WHAT WILL SUPERFERGIE DO? 

As stated in my previous post (Doling Out a Giant Bog of Fudge Pudding – Tasmanian Times) TasWater required DPIPWE to seek public submissions to their application to decommission the Waratah Reservoir.

The local community has provided multiple and varied submissions to the required DPIPWE official Bill Shackcloth prior to the closure date of 1 February.

The submissions covered all relevant aspects with one single focus – rehabilitate the reservoir for the future of Waratah.

The below commentary from an informed resident of over 20 years history, is symbolic of the breadth and passion (dare I say anguish?) of these submissions.

Quote: 

Waratah reservoir and wetland was a large relatively shallow 52 ha lake with a water frontage of 15 kms.  

It is a naturalised lake, manmade around 120 years ago.    

It is fed by a catchment and springs beginning 2 kms upstream from the dam wall.  

It has a very small catchment, which lays directly behind and beside the lake.  

After permanently draining 2 metres of water by lowering the spillway, the lake and wetland now covers an area of <18 Ha with a water frontage of <4 km.  

52 ha down to <18 ha.  

15km down to <4 km.  

The distance from the dam wall to the Waratah Ponds is 1.4 kms. The drop in height from base of wall to Waratah Ponds water level is 6 metres. Steady grade all the way.  

The lake and wetland is surrounded by sedges, rainforest, native Poa lab grasslands. Some broom and gorse weed infestation – past infestation was significant.   

Note-local landowners and Landcare Group have been working hard for over 20 years to keep the weeds removed and controlled at their own expense.  

In 2004 local residents applied successfully to have the land surrounding the lake an environmental zone.    

The sudden dramatic lowering in August 2017 of the water level resulted in the reduction in the area and perimeter of the lake and wetland. This immediately resulted in major problems for wildlife relying directly and indirectly on this lake and wetland for survival.  

This includes but not limited to breeding sea eagles, native waterfowl, astacopsis tricornis, native burrowing crayfish i.e. Engeaus fossor and another yet unidentified aquatic burrowing crayfish, platypus, rakali, eastern barred bandicoots, ground parrots, masked owls, wedge tailed eagles.   

Sea eagles and platypus are highly territorial with displacement and or death obviously the only outcome for these protected native animals.  

  • Waratah Reservoir was suddenly drained 1.5 metres in August 2017 by TasWater by lowering of the spillway. This was because of alleged imminent failure of the dam wall.  This had a catastrophic effect on the life in the 52 hectares, 15 km water frontage lake and wetland with displacement of significant numbers of platypus and trout downstream, displacement of rakali, and nowhere for sea eagles to hunt for food.   
  • Permanent displacement of pair of resident breeding sea eagles (known for at least 60 years to reside and breed in the reservoirs area) and their juvenile occurred.  Juvenile last sighted by me and another person October 2017 sitting on exposed logs in shallow water in eastern end of lake by itself, no parents been seen since September 2017. Juvenile appeared to be attempting to acquire a wood duck as the flock of wood ducks flew up from within metres of the eagle as we arrived, brown juvenile also flew up in front of us and into the direction of the southern arm of the reservoir and into a large tree on the hill to the south.  No parents seen anywhere in vicinity. V-shape of profile was clear and bird very large easily identified as sea eagle. Had been sitting perched in exact same place as parents had been regularly seen prior. Unknown the fate of the juvenile.  
  • The following summer 2017/2018 resulted in very warm temperatures for weeks in the lake of 24 degrees C, as measured by author, very hot days in the mid30s, and lowered oxygen levels from very low and restricted water flow resulting in resident Astacopsis tricornis going to bottom seeking refuge and not surviving. Astacopsis tricornis were surveyed in good numbers in the Waratah and Bischoff reservoirs by Inland Fisheries Tasmania in the 1970s and 1980s. I have seen them personally in all four Waratahs lakes and Waratah reservoir up to draining Waratah reservoir in August 2017. Information on survival of A tricornis in warm water gained from Todd Walsh. Warm summer temperatures have persisted for seasons since and no chance the Astacopsis tricornis could return to the lake until water levels are raised.    
  • I have observed and photographed burrows and observed burrowing crayfish exiting from burrows around shallow water edges Waratah Reservoir within 200m of dam wall. Engeaus fossor at least existed in far reaches North and South Arms prior to draining 1.5 m. I will make it clear that Entura surveyors walked over the top of (observed doing so by Author) exposed burrows within 200 metres of the dam wall of Waratah reservoir repeatedly doing their short survey yet failed to observe those clear signs of unknown burrowing crayfish species. ‘’No-one saw the Elephant in the Room.’’ They also walked past obvious burrows in the shallow water where same colony had relocated after water levels dropped. These have been seen by myself personally and are NOT Engaeus fossor. They are NOT introduced pest Cherax destructor. I had notified Alastair Richardson in an attempt to find out what they were and to date unknown what species. He suspected to NOT be engaeus after I gave him a description of location burrow crayfish and photos of burrows. They are a small aquatic native crayfish.   
  • The numbers of frogs have plummeted in the reservoir and wetlands evident by the frog sounds that were heard prior to draining in August 2017.  One year later to the day very little sound. Been the same since.   
  •  Its basic high school biology – Pull the rug out on food supply in the food chain and the apex predators, animals at the top, will suffer. The lake and wetland provides a HUGE amount of food by its very existence and correct function at original water levels. Wedge tailed eagles live hunt and breed close by. Sea eagles used the Waratah reservoir to breed and hunt, used the Bischoff Reservoir to hunt. These beautiful raptors would visit Bischoff reservoir and my property where I reside twice a day morning and late afternoon then flying back to Waratah reservoir. Author observed this for 16 years until they disappeared in late 2017. Not seen since.  
  • Water flows in winter are significantly higher than summertime. The rainfall alone is looked at but does not tell the entire story. It is heavy snowfalls followed by heavy rain causes significant amount of water going into the catchment in a short space of time. The reservoir until August 2017 acted like a huge shock absorber, absorbing the sharp sudden increases to water flowing into and down the river into Waratah township. Some level of control is to be enjoyed with the Waratah reservoir dam and operating gate valve to buffer the town from road damage from flooding. Of significance is the risk to the weir, the only thing holding back water for the water treatment plant, and the road culvert beside Fagan’s sheds at the top of the waterfall.   
  • In contrast, in January 2019 the water coming from the Waratah reservoir slowed to a trickle. A trickle was running through the timber weir in town.  When a fire threatened the town the Fire Services drew water from the mains close to the fire twice, before the supply shut down. The levels in the Waratah ponds dropped where the intake by treatment plant is situated, thus apparently drawing AIR into the pumps. A water main then blew out in town and water was unavailable in the mains supply until repaired many many hours later. The weather was very hot, very dry and blowing north easterly. The fire tankers travelled a distance to draw water from the Waratah Caravan Park pond to the top of Magnet Valley to extinguish the fire, with assistance from a water bombing helicopter luckily in the area and diverted from Rosebery fires. Water was airlifted from the lower Waratah Ponds. The author has recently seen how rapid the spread of fire through wet eucalypt forest is even after a fairly damp summer with rainfall the week before i.e. still had ground moisture. This was 18 km from Waratah. The bushfire threat to Waratah during a hot dry windy summer as in the 2018/2019 Summer cannot be ignored nor dismissed. It is inevitable. Surrounded by vast Eucalypt plantations, Poa grass plains, and native Eucalypt forests consisting of dense stands of forest with large stringy barks and mountainous terrain, it will not take very long for Waratah to be under threat. Finite resources stretched and the township is on its own. In an isolated area water levels maintained for firefighting by the local brigade helibombers and a functioning water mains system is imperative. Into the future and present helibombers will be used for and more for the majority of firefighting operations. Close by water sources make all the difference to rapid attack. The author can foresee and predict if the Waratah reservoir dam wall is removed, significant winter flooding will occur, and significant dry summer years the weather will result in no significant water coming down the Waratah ‘River’, which is not a river but fed by seasonal springs 3.5 kms upstream from Waratah township. There will be a dire need for water to be released from upstream to replenish very low levels in the Waratah township ponds.  
  • The dam wall in its current state is not a danger as the spillway has been deepened by 2 metres and widened since 2017. The front of spillway has been cleaned out of collected silt and debris. An operating gate valve has replaced the seized old one. This dam wall is of very little difference if what smaller than most farm dams in Tasmania. The drop of 6 metres over 2.4 kms is a gentle grade from dam wall to the top Waratah Pond. Gentle all the way.   

In Summary  

  • Waratah reservoir- wetland, lake and dam needs keeping for the benefit of native aquatic life and all native wildlife that naturally inhabit the lake and wetlands. Including rare, endangered, vulnerable and protected species and their food sources and habitats.  
  • Waratah reservoir and Dam needs keeping for future water security for times of extreme dry, for replenishing downstream to Waratah Ponds, for firefighting purposes, and as a shock absorber for heavy snow followed by heavy rain.   
  • For the mental and emotional wellbeing of people who use the reservoir for recreation and relaxation, both locals and tourists.  
  • The dam wall in its current state is not a danger as the spillway has been deepened and widened from the original.    
  • The author’s preference is for the reservoir level to be reinstated. Or left alone as it is so to not destroy or displace any more wildlife.  

Unquote:

A chronicle of amazing depth and understanding.

Perhaps the most interesting (which of course TasWater and Entura will deliberately ignore) is this comment “clear signs of unknown burrowing crayfish species.”

Is it possible that they might be those of the short-tailed rain crayfish (Ombrastacoides parvicaudatus) recently identified at Lake Burbury?

Well, that would certainly make it interesting for the recalcitrant “I know nothing” Minister Michael Ferguson and the TasWater Board and Management Team, and the environmental surveyors in Entura.

And of course, there still remains, the not well-known deposit of kryptonite hidden in the mud at the base of the reservoir, which will be revealed if the decommissioning occurs.

SuperFergie will be goneski!