Friday, April 08, 2016

Vegetation is about to take over -- so what's the plan ?

These pictures were taken on 8th April showing last seasons boundary of weed growth about 400m from the shore north of the Yacht club ,
Over 100 hectares of growth has occurred already below the new highly shore line established in the 1980's. This year new large areas of reeds  and docks and other tough colonising plants can be expected to take off over the next few months creating a management issue of huge proportions.


While a good depth of water is desirable its unlikely that  we will get the 4- 600 mm of rain in the next few months to kill the new areas of  growth.  Presumably in the past , grazing by stock helped reduce this risk...... and yet its not stated in the plan .
The  autumn rain ( 15mm on 6th ) can be expected to get lots of new growth going on the dry surface; areas that previously carried no growth .




Unless the management plan address the existing 100 ha of  growth,  the amount could easily double before next year .The highly fertile soils  and high moisture content will mean removal of this  material could be very difficult. How can we hope to retain the lake as a place for recreational use by boats ?
This new reed growth is happening in the clay only area about 500 metres from the shore .

April 1st 2016

The lake officially declared dry . Easter saw several people celebrate with a cross out in the cracked clay.

















Others,  in their walks,  have found anchors and substitute anchors like this one
and this
and this 

What to do with Lake Colac?

Pleased to hear from the ranger in charge James Gorman   that the meeting held late last month reflected the result of our survey -- that the people want a range of State experts to make a recommendation. Sarah Henderson is just another  person to waste OUR money on yet another consensus survey .
Might rerun the survey if we have another public meeting and lets hope Andrews government come to the party in running more than just another superficial survey.

Thursday, February 18, 2016

When tough and rigorous science is needed - ie NOW

I truly hope the meeting on the 25th ( Lakes Bowling club) over the lake is not another talk fest.
Without the tough medicine of a better water budget , any scheme to revive and improve the lake  is doomed to failure , The only water that we will ever get is the water  we get now - so we just have to use it a whole lot better - and that means two lakes - One more permanent than the other,


Think
The only way something as complex as this lake system is to change is if the State Authorities study it properly .We have had a whole century of wishing and hoping , thinking and praying  but most of it talking around the edges - the same old same old problems of shallow and inadequate water supply.  (both for aquatic life and aqua loving life ) -
--So we haven't been willing to grab the water bull by the horns .We have had the courage , not that many years ago, to raise the water level by raising the  weir down the Meredith Park end by over a metre.
--Have we the courage to put the weir where it would work,,  or even more importantly talk about weir specifics at Thursday nights meeting?
Like some notorious political movements , it seems to me our leaders are afraid of upsetting somebody - esp those who might  give in to a bit of half worked through worry and self maintained ignorance. Sure a cuaseway will change the view but not enough way out there to stop the lake's exapnse being obvious ,Infact everyone who uses it will surely say " Must stop here sometime"

Yet we have this consensus breeds sense nonsense . The only stakeholders who get to influence these dumb processes are the big stakeholders . Is this really the way to move forward ?

-- "We'll canvass all opinions and get back to you " is not enough if most of us IMO just want someone to study and make a studied recommendation on the real possibilities - its called making an informed decision " . In 100 years no one has got back to us except a few with hard edged decisions like ones sought for by a more clear thinking Council in 1942.

Sure there are downsides and I am certainly not ignoring them( see previous posts )  What this fear and giving into factions first up does is produce,  not solutions, but ineffective sidelines and tokens ; attempts to cross things off the list without examining them properly . Another $50000 on talk fests from Sarah Henderson wasted .  (I hoped that wouldn't happen after the meeting and said so in a previous edit  )
Instead of  properly researching and  facing up to the tough tests of the biological and engineering truths we end up half way doing nothing - cause its easier . There is, quite clearly,  by treating Nature as family,  a strong possibility of worthwhile change  ( a eutrophic lake is by definition a dying lake

--We can design something that will keep more birds and fish than we do now and  with the same 200 -300 million .How many birds and fish have been in there in last 10 years ?
--We can be expected to achieve all that is there now ( without always having algae fish and life kills some new and bigger resilience targets ,  not just the inevitable eutrophic death and dying,that we will get for the next thousand years;
--We can have more --at least 2 new ecosystems that have perennial life ,
--We can  still have the old type of eutrophic lake-- up north more ?
--We can have trucks crossing the lake without them looking too big from key vantage points ( see earlier posts )


My suggestion;
Vote for a State government sponsored proper scientific review of the possibilities - which should include ways to raise and keep the water level higher .Will such a motion be put at the meeting? I have another appointment that day , so I wish you well

While the AURECONS report  is completely inadequate as a  study of all the issues,  at least they made some estimates of the costs.( up to 300 million)
Interestingly a causeway really close to north shore  would be a new type of proposal of little interest for sailors  but would be easier to manage for water quality and levels .   I think far too close for everyone's general comfort. But that's all to be discussed once the State shows a causeway is a positive possibility.

We haven't got even a way towards " how far out would be best for the causeway " YET. Clearly it can't be more than half way out as an effective long term water budget won't spread that far .

Whatever the change , How much different is to putting in  a weir , or shifting the existing one at Meredith Park ?

Here the link to the report by Aurecon’s
four bypass recommendations and the estimated costs for each route.

http://www.colacherald.com.au/2013/03/381m-price-tag-for-lake-bypass-option/


Thursday, January 21, 2016

21Jan 2016

Low rainfall low runoff over the last few years and our lake is about to dry out ,Range of birds still feeding in SE corner ( view from pier)  The water is still a long way out .


  The view near home


Anyone who wants to constructively discuss the future of Lake Colac is welcome to join in the discussion on http://lakecolac.blogspot.com 
While many favor leaving it as it is , I as a geomorphic landscape planner favor change. We have watched the fish die and birds disappear for decades .The lake is not an ecosystem but a series of death threat events in a eutrophic lake - see blow for more detail .

 Talk of a regatta has been just that for a hundred years and will remain that way for another hundred if we do not embrace the only change we will ever be offered- esp one  that we can afford .Dust too will increasingly be our lot as it is the natural product of this sort of temporary water basin. also Lakes and Craters Australia FB page  Will post a picture of the blown out boundaries sometime .




2015

2014

Thursday, April 25, 2013

12 April 2013

The birds are only small , inactive and not overly large in number as there is still some growth in the still relatively clear autumn waters . 
How much lower will our Lake go this year ? As shown on the graph here , the evaporation about matches the rainfall around now ,so little lake level fall is likely .

What is deeply disturbing is the growing area of potential swamp ( now out several hundred metres ) an area and boundary that can be expected to grow rapidly this year .
What are our Councillors doing to plan for this / you better ask them . 

Monday, April 01, 2013

Outside profs need to get involved to be taken seriuosly

What should happen to Lake Colacis a complex matter and will take time to get some sort of consensus. We don't need know all's and we don't need outsiders with a "no can do" attitude; Its always easier to do nothing till we have nothing left .
Problem solving isn't helped  by Councils who trust outside so called academics and outside experts who press the kill button on people's questions . When people like Prof Gell get involved with a proper review of the details of a bypass proposal , I will take them seriously. So far its just one careless comment.  
The floor of the shallow basin we call Lake Colac is already dumping dust on Colac ( in dry periods ) and will continue if nothing is done to change the basic hydrodynamics.  If heavy metals are a problem Mr Gell can tell us now about how much we have recieved , without getting side tracked into finding just another reason for our Council to say and do nothing about it. Clearly 2 lakes will lower the load into north Colac at least .
Mr Gell wants us to believe  we can't do anything ; the problems are 'unmanageable "  Seems like even academia , like the Greens , need a lesson in how to not despair of everything we do and our ability to do anything .Come on Mr Gell; get seriously involved .

Monday, March 18, 2013

St Patricks Day 2013


The last significant rain was in late November . It rained a few millimetres on the Kana parade at the weekend. Our normal non growing season of 2  months is increased this season  to a 4 month dry break .This probably means effective net evaporation of the warm water in Lake Colac of 200-300mm. However the lake is not going back as fast as this figure suggests ( photo to come). Its been dry hot and stable (like the nature of "high pressure"  has been? - slow moving and centred on this latitude)  Maybe the lack of wind is important in the lower apparent evap rate .



Wednesday, September 19, 2012

QC7 - Is water quality likely to be the biggest natural challenge if a causeway is contructed?

Probably. (Noise at certain times ? See much earlier posts for visual impact )









Well published water pond planner Nick Romanowksi is, like many,completely opposed to the idea of changing the lake in any way at all ( Colac Herald 31st August)
As an ecologist I have a lot of sympathy with his view that managing water quality will be a difficult issue.I don't however think we should not modify the presently highly modified systems  just because its seen to be interfering in nature . The water quality is very poor NOW because plants and animal can't reliably use its huge nutrient load.  Decomposers are the main functioning biological elements  operating in the lake at any one time.
What we do need , in my opinion,  is to make sure we are working with nature , not against it ; That we are working with natural systems,  not presuming they will not change and that we cannot  be part of that change to more diversity too .As stated previously the water body does not function as a stable ecosystem because its very shallow ,wave prone with its dispersive clay content not allowing consistent algal growth .
I can't see any real reason why we can't have a  more " natural " lake up north than we have ever had and a more diverse stable water body to the south by planning development and design systems  that are thoroughly committed to managing nutrient loads  and using the earthworks for a road to do much more diverse things to the water bodies adjacent . There will be no other time we could afford to consider anything else. 

Time for your questions?