A visit to Genoa etc

 I decided to go to Genoa on 22 June to check for Cattle Egrets and (being very hopeful) the Emu.  I also went out on the new bridge to check the water level in the River.  Quite a good flow, but still plenty of sand visible.

The BoM shows that water level at the flood gauge (about 12km upstream) is well below any of the flood levels.

My birding started on the far side of the village looking out over the paddocks for the Emu. it wasn't there, and hasn't been seen for some time.  However a pair (making a few judgements about their level of friendliness) of Brown Falcons were perched on the windmill.

After checking the River I crossed the highway and spotted a single Cattle Egret with some Herefords.

Pulling into the gravel patch there were a lot of waterfowl  on the main pool.  I counted 218 Pacific Black Ducks, which was not well received by the eBird tolerance monitor until I put in a comment.  My full checklist is here.  The white breasts of the 33 Masked Lapwings stood out well.

It is not unusual to find a few Australian Shelduck here but a count of 21 was higher than normal.  It seemed that various forms of pair bonding (and aggression between the males) were going on.

On the Sunday I went to the airport.  It was a swamp: I spent quite a bit of time in 4WD on the basis that prophylaxis is more efficient than therapy!  Best bird was a Tawny-crowned Honeyeater on the fence near the terminal.

Minor flooding

 Yesterday the BoM issued a minor flood warning for the Genoa River.  The gauge at the Genoa Gorge shows that happened late yesterday, but it has now dropped below that level.

The drop has yet to get to the lower parts of the River!

Sorry about the poor focus: camera wasn't happy with the lighting!

Good that PFDs float.

I did ask a Shire worker when Parks were going to open the Mouth.  He laughed and commented that "We haven't got that phone call yet."

A couple more snaps from Karbeethong Jetty, later in the day.  As it has continued to rain all day I suspect the level will be higher tomorrow morning.

24 hours (and an inch of rain) make a difference

 The difficulty of birding from Captain Stevenson's Point recently has been the vast expanse of sand visible. I can't track down a recent photo of this as a 'before image but here is a snap from yesterday (25/10) to show a total lack of sand.  The banks are sort of visible as the areas with a yellow tinge.

The only waders visible in this view were 2 Masked Lapwings in a patch of Samphire near Goat Island and an Eastern Curlew on a clump of detritus towards the Wharf.  A flock of Bar-tailed Godwits and a few Red Knot were seen at the channel to the Mouth when looking over Devlin's Inlet.

That sight made me wonder what might be visible from the beach at Bastion Point so I took myself off there and walked out to the Mouth Channel.  The current through this channel was as vigorous as I have ever seen it!

Being a very intelligent person I had left my camera at home.  Closing in on the Nobel Prize for Stupidity I also left the adapter to connect my phone to my telescope in the car!  However I was able to line up the phone on the eyepiece to get a few record shots of about 50 of each of Red-capped Plovers and Red-necked Stints foraging in the Eel Grass washed up on the far side of the channel.  I had wondered where all the Plovers had gone.

Actually I step back from "record shots": they aren't that good, but they get the idea across.

To further illustrate the level of water in Bottom Lake on the way home I took this image of jetties at the Fisheries Jetty turn out.

Measuring wasn't meant to be easy

When Medium Sized Mal (Fraser - the only Big Mal around is Meninga) said "Life wasn't meant to be easy." he was probably not thinking of trying to estimate the width of the mouth of Mallacoota Inlet.  It is however not an easy task without a good range finder.

The first estimate of the width was by Michael York who offered 100 m.  His difficulty was finding someone to hold the other end of the tape measure.  

I had a crack on June 20, taking compass bearings from a couple of spots on the Western side of the Inlet to a lump of seaweed on the Eastern side and plotting all this on Google Earth.  All a little dodgy, but gave an estimate of 130 m.  I think it was close to high tide.

My first effort on 21 June was from Captain Stevenson's Point.  That was not possible as there was very difference in compass bearing to the Western and Eastern sides of the mouth.  So I had another go from the lookout at the far end of the Campground.

I took my bearing to the end of the sand spit on the left of this image and a point on the right hand side as close to directly opposite this as I could estimate.  From the image it is very clear that the tide is quite low (and that the water depth is very low for about half the width).

I plotted the position of the lookout and the two bearings on Google Earth.  The two big clumps of shrubbery inside the SSE line of this image no longer exist (well, not in that position: I think they are now somewhere near the wharf).  The Mal-ific  difficulty here is that for precision it is necessary to know how far along the lines the actual mouth is situated.  My guess is represented by the green line: this is 120 m long.  A line joining the two pins is 140 m long and it was a good bit closer to my position than that.

Trying to bring all this together I think I would say that the width of the water varies from about 120 m at low tide to 140m at high tide.  Noting the area of shoaling in the second image above I'd suggest that the usable width would be somewhat less than half that at high tide and a lot less at low tide: possibly a jet-boat would be helpful! 

Who has stolen Bastion Beach?

 I went for a stroll to Bastion Beach on 18 June (at about mid-tide) to check what the big swells had done while we were away.  I had got some idea by walking down the pumping station track on the 17th: clearly the water level at the beach end had been well above normal, having knocked quite a few planks out of the boardwalk.

In summary a lot of sand has disappeared from the beach. This first image shows the wash lapping at the bottom of the steps, just after a swell had broken.  Between breaks the water would be out of this frame.

To get onto the beach, with some certainty of keeping my shoes dry, I had to clamber across the rocks to the right of the steps.  In recent times the usual level of the sand has been to the bottom of the second vertical pole.  Perhaps a metre higher,

The next image shows the length - if that is the right word - of the beach, and the width of the mouth.  I have seen an estimate of it being 100 m wide and wouldn't argue with that.

The track recorded by eBird shows my walk as ~900m return so probably 400m from the steps to the mouth.

The background offered by eBird dates from sometime in the recent(ish) past, but clearly the mouth has moved at least 600m towards the steps.  There are a few comments on various Facebook posts recording how it has shuffled back and forth over the last few decades - from the base of the steps to Harrison's Channel and back again.

The next image is a snip from the above zooming in on my track.

The light blue dashed line is the approximate edge of the water when I was there.  The dashed green line is a tide mark of debris and weed which I think marks the recent high water  mark in Develings Inlet.  The next image shows where the waves have thrown seaweed etc over the beach near the steps.

The red arrow indicates an area where the sea had been breaking over the beach: if that had been sustained it would have taken another 100m off the beach.  Here is the (near) cut through: note all the flotsam at the end of the sand.

After this walk I drove past the mouth of the Betka River.  The entire sandbar on which the Hoodies used to nest has been washed away with a vertical face to the dunes.  

A close up of the remains of the dune.

My guess would be at least a metre of sand has vanished.

A weather event shapes up

 On April one a post on the Mallacoota Community News Facebook Group (MCN) linked to a BoM Flood Warning page under the heading "Here we go again".  That seems to be a very fair call.  At 0730 on 2 April the Warning included 

"Minor to moderate flooding likely across parts of West and East Gippsland from overnight Saturday into Sunday with major flooding possible in the Cann and Genoa catchments during Sunday."

At home I recorded 5 mm of rain on 1 April and as at 0730 have 17.2mm since midnight (those data will not count towards the 2 April total due to the 0900 switchover 😠😠.  The current Bairnsdale 256km radar image suggests that we are in for a bath.

Cutting to the chase, we got an Olympic Pool rather than a bath.  On 2 April I recorded 144.2 mm (2nd highest recorded at Mallacoota out of ~17,000 observations) and on 3 April I had 120.6 mm (7th highest).  The 2 day total (264.8 mm) is ~30mm more than any other consecutive 2 days since records began. The BoM total for Mallacoota Airport was 213 mm (itself the third highest 2 day fall) and recordings there were generally lower than mine but a comment on Facebook by a resident, close to our house, indicated her readings were close to mine. 

Total rainfall since midnight, as at 1400hrs on 2 April was 83.2 mm at home according to my WS.  My Nylex had 81mm which is close enough to the same!

I went to Bastion Point to check out the state of the ocean: as shown here, a trifle lumpy.  I swung by the wharf to check the level in the Inlet.  It was at 0.56m, an increase of 0.08m since I was here at 1100 hrs: I'm not sure to what extent that is due to rain coming down into Bottom Lake; tidal variation; or the wind and swell driving the ocean inland.

By 1424 the radar was suggesting that the worst of the rain was occurring to our West and Mallacoota only had light, if any, rain.

Looking out the window, with the Narrows barely visible through the rain, suggests that is far from accurate.

The rain, together with a SE gale blowing water in through the mouth led to the Inlet being quite high for our morning walk on 2 April.

The official gauge at the Main Wharf was registering about 1.1m ( I couldn't get close enough to read accurately).

By midnight on 2 April my WS had recorded 144.4 mm of rain.  That is the second highest in the records for Mallacoota (the highest being 192.4 mm on 20 May 1978).  

• The BoM site at the airfield recorded 113.2 mm  (which would be the 9th highest reading in my data set) over the calendar day, while BoM at Gabo Island recorded 72.4 mm.  
• A wunderground station in the town centre has recorded 111 mm for calendar 2/4/2022.  
• At one point in the morning of 3 April a friend reported - somewhere on Facebook but I can't relocate it - that she had recorded 177mm at home on Intervale Drive.
• My Nylex, positioned about 5m from the WS)  continues to give readings very close to those of my WS.  

Obviously there are cells small embedded in the continual flow which greatly boost very localised falls.

The following charts show the hourly fall and rate across the day.

The rain has not gone far inland with Bombala AWS - near the head of the Genoa River only recording 5.2 mm since 0900 0n 2 April.

As Excel will not create column charts with two vertical axes I have used a line chart instead to show the falls on 3 April at my WS.

The Flood Warning early on the 2nd said 

"The Genoa River at The Gorge is currently at 1.25 metres and rising. The Genoa River at The Gorge is expected to exceed the minor flood level (2.20 m) overnight Saturday into Sunday. The river level is likely to reach the moderate flood level (2.90 m) Sunday morning."

In fact it got to minor flood level and has since receded.

Looking at a pressure map on the BoM site the event certainly appears to meet the criteria for an East Coast Low.  It also appears to be moving closer to the coast through at least the morning of Sunday 3 April.  That being said the latest radar images show no rain the area with the only registration being a band of squalls about Cooma!  

Obviously the last paragraph was a case of speaking too soon!  Shortly after composing it we went for our morning walk and it started raining again.  That is reflected in the hourly chart above.

I also downloaded the Meteye 3-hourly rainfall forecast totals for the next two days and will compare that with actual.  We are currently at the 25% probability level for the period starting at 0500.  By 1400 my WS had recorded falls greater than those forecast with 10% probability by BoM while the BoM site had recorded falls greater than those with 25% probability (but slightly below the 10% level).    This image shows a comparison across most of the 2-3 April period.

In summary for 7 of the 15 periods both my WS and Bom recorded falls > the Meteye 25% probability forecast and for the evening of 3 April both my WS and BoM recorded > the 10 % probability fall.  My WS also exceeded the 10% probability on 3 periods on the 2nd.  Allowing for some site-effect being evident with my WS the Meteye forecasts are I think pretty  good: we should have beaten the 25% level on 4 occasions and did so on 7: we should have beaten 10% on ~2 occasions and did so once.

A final note is to look at what has developed with my pro-rata estimates of the annual total for 2022.  In the past I have ignored the very high estimates generated by falls in the first week of January.  This year they have looked like the shape of things to come so I have left them in!

Genoa Gorge

 I have long intended to visit the Genoa Gorge, firstly because the name sounds interesting and secondly because there are a heap of interesting birds seen in the immediate area that are not found elsewhere in the Mallacoota District.  The latter include Diamond Firetails, Yellow-tufted Honeyeaters  and Turquoise Parrots, both of which were seen on a recent visit to the general area (which didn't go to the Gorge itself).  With the weather of 29 January being relatively benign Frances and I headed off there.

The starting point is the turn off the Princes Highway about 1km North of Genoa, marked to Wangarabell, Wroxham and Nungatta.  Its about 10.5km along a well surfaced (but twisty) dirt road to the (un-named) track to the Gorge.  Google Earth is your friend.

EBird track marking function is your friend for showing the track to the gauging station.  This track was taken as we walked down.  Having done so, I'd rate the track as high-clearance 4WD only: and with VERY careful picking your way through the ruts.  (A concrete pipe is evident at one point with great potential to damage suspension.)  It is about 700m to the end of the road and drops (according to Google Earth) about 30 metres to the gauge shed. 

The start of the track is quite steeply downhill and the surface is very slippery in spots.  I removed  a little bark from arm and knee to validate that statement!

The density of the regenerating vegetation is evident in that image.  It made it rather difficult to see birds but there was a lot of vocalisation indicating they were around.  I suspect my list omits quite a few whose calls I didn't recognise.  Bird of the day was a clearly seen, but not photographed, dark-phase White-bellied Cuckooshrike.

The track ends at a shed housing some of the gear.  It is several metres (~15?) above the river.  This image was taken about halfway vertically between the shed and the water.  A handrail for a set of metal steps descending the final bit is just visible to the left of the tree trunk.  We went to the steps but not down them!  This looks like a granite sill .

There is a good flow in the river.

The BoM site (under River Conditions) shows the flow to be well under flood level.

Looking upstream shows the actual Gorge.