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Hi everyone,
Does anyone know how to calculate the tides for Lake Cooroibah? I see Willyweather has tides for various sections of the Noosa river until Tewantin.
Does anyone know how much time difference there is between Tewantins tides and Lake Cooroibahs?
Thanks
hey shauno. there was an app that gave you the tide based on your location and it also gave you tide times when you marked google maps but i cant seem to find it at the moment
Nearly reverse up there.
Agree with Gunna. ffej always told me above Johns Landing high was low and low was high.
Yes, as chewy says, but lake Cooriobah is the first lake and it will be somewhere between the two, so no idea is the answer. If I was to take a guess, I'd get Tewantin tides and add 2 hours, but that's a guess.Quote:
Originally Posted by ActiveAngler
I would say 15-20 minutes later than Tewantin.
I reckon its a good half hour difference from Tewantin,its about 5ks up to Coorooibah from Tewantin.
Ok thanks everyone. I will post if I work it out.
Noosa Hd is the standard port.
Tewantin (secondary) has a time lag of 1.07 hrs for high tide and 1.49 hrs for low tide. Just add those times to Noosa Hd times for Tewantin.
Cooriobah is approx 5 km upstream from Tewantin so add about 15 minutes to Tewantin times.
That makes Cooriobah approx. + 1.20 min for high tide wrt to Noosa Hd high water times.
And makes Cooriobah approx. + 2 .00 hrs for low tide wrt Noosa Hd low water times.
The tides at Tewantin are not 6 hrs in and 6 hours out. They're 40 minutes off 6 hours. Therefore i/c tidal stream is a bit faster than o/g tidal stream to maintain the 12 hour cycle.
At Rockhampton City (50km from Fitzroy mouth) the tide times are roughly 5 hours in and 7 hours out. I/c tidal stream runs like crazy. O/g tidal stream is slower taking an extra 2 hours to drain out the water that the i/c stream put in there in 5 hours.
Not rocket science.
Be careful with Willy weather. They're reviewing all of their secondary port times and tide heights because they were basing them on the incorrect datums in some places along the coast.
From Willy weather on 11 Nov. They'd been working on the problem I'd pointed out to them for about 4 - 5 months. Use MSQ tide tables if you want correct tide info until its sorted out.
Hi Ron
We haven't forgotten our discussions on this and thank you again for the precise information you provided. We are waiting on a full database update before the Fitzroy River situation can be resolved. This will be the first update in some years. It is a major undertaking with high potential for disruption of our service. Every change has to be checked and cross checked, and there are thousands of changes, but hopefully we'll have the update done in the next few months.
best regards
Greg
WillyWeather Support
It'll be interesting what you find Shaun, there is two large ( but shallow) masses of water in the two lakes, it does funny things. Fishing the stretch of river between the lakes, you can fish a tide at one end then move and fish the same tide at the other end. As chewy said the up stream end of the between the lakes stretch is the reverse of the river mouth, but then again some days it isn't. Simple really!
I look forward to your findings.
Do you imagine that the differences (if any) might be associated with the full/dark moon tidal behaviour and the neaps tidal behaviour at the top end of 1 lake and the bottom end of the other lake? With both different to the standard port.
Significant differences that exist in 1 place between neaps and full/dark moons also happen in other places.
Imagination is easy.
I guess others will look forward to the "findings" as well, eh Didley?
have you actually fished of boated on the nossa river upstream of lake Coorooibah Douglas?Quote:
Originally Posted by Douglas
I guess that the differences in the joining stream will be related to the amount of water that has to be shifted between the 2 lakes (that varies from tide to tide) and the varying times in which that varying amount of water has to be shifted?
No and don't have to Paul.Quote:
Originally Posted by ActiveAngler
Issue is movement of water between 2 constricted waterways. You could liken it to two reservoirs connected by a 8 km pipeline.
Reservoir 1 is Lake Cooriobah and reservoir 2 is Lake Cootharaba connected via a 8 km pipeline and they're trying to balance (allow water from both to find a common level).
Only problem is there is extra water pumped into the bottom reservoir via the tides at regular intervals. How much water (and consequently the difference in "heads") is determined by the tidal differences between Tewantin and Noosa Hd.
Then the effect of water movement between Cooroibah and Cootharaba is dependent on the difference in the incoming volume of water via Tewantin. And THAT amount is dependent on the moon phase.
That's why the tidal differences aren't static.
The two lakes are differing volumes so one (Cootharaba) will tend to dominate what happens in Cooriobah.
Think about the VOLUME of incoming water via Tewantin and its effect on the head of water in Cooriobah. Easy to work out knowing the surface area of Cooriobah and the volume of water from Tewantin.
How much then needs to flow into Cootharabah ( if Cooriobah's head is above Cootharabah's head). With a larger surface area in Cootharaba,, a flow of water from Cooriobah which reduces its level by say 200mm won't produce a 300mm increase in Cootharaba.
Furthermore a reduction in level in Cooriobah can be easily mistaken as a tidal peak changing to an ebb even though the tide is still rising at the Tewantin end of Cooriobah.
If incoming volume of water from Tewantin is minimum( neaps) then the head available in Cooriobah is less than what is usually available. It might even be below Cootharabah's level. The head in Cootharabah and the flow in the 8 km pipeline going past St John's might continue in the same direction irrespective of the tide. So we're not really dealing with predictable tides in pipeline or Cootharaba.
Once again, the increase in level in Cooriobah caused by the inflow from Cootharaba can easily be mistaken for incoming tide when in fact the tide is ebbing at the Tewantin end of Cootiobah.
If there are longstanding observations in respect of Cootharaba then things might be different but even if they exist they will be one step removed from tidal predictions which are considered as reliable.
I think Tony and Paulo are pretty much spot on. Somewhere in the 20 to 30 min window after Tewantin.
Chewy summed it up pretty well too in another post.