Data: Porth yr Ogof. 18/08/2015. Maxwell Fisher. Dived.

Your name:	max fisher	Observation date:	18/08/2015
Site Visited	Porth yr Ogof

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Church Sinks Observations
The river water was Flowing under the bridge
Church sinks flora: small flow down river
Church sinks fauna: n/a
Church sinks water temperature:
General Church Sinks observations:

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Top Entrance Observations
Accessible by walking up the riverbed?: Yes
Top Entrance Flora:
Top Entrance fauna: 2 trout just inside entrance area
Top Entrance water temperature: warm, 5mm wetsuit dive
Top Entrance general observations:
Dives done into Top Entrance?: Yes

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Top Entrance Dive Log
Top Underwater Visibility:
Top Water flow:
Tope entrance underwater fauna:
Top Entrance other observations:

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Tradesman's Entrance Observations
Tradesman's flora: green ones
Tradesman's fauna: 2 trout
Tradesman's water temperature: warm, 5mm wetsuit
Tradesman's water level: below
Did you dive at Tradesman's Entrance?: Yes

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Tradesman's underwater visibility: 4
Tradesman's water flow: medium
Tradesman's underwater fauna: 2 trout
Tradesman's general observations: line ok all way to four ways airbell

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Main Entrance Observations
Main Entrance flora:
Main Entrance fauna:
Main Entrance water temperature:
Main Entrance general observations:

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Resurgence Observations
Resurgence flora:
Resurgence fauna:
Resurgence water temperature:
General resurgence observations:

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Little Neath River Cave Observations
LNRC Observations:

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Final Observations
General Observations:

Blog post: Flood pulses and Secchi measurements....

There has been lots of work going on at Porth yr Ogof thanks to divers beginning to get on board with Project Baseline South Wales Caves.
Somerset Section Cave Diving Group divers Mike Thomas and Kevin Hilton have been visiting Porth over the summer and not only has the Secchi disc been installed, but the line leading up to the disc has now been tagged. This means that visibility measurements can be taken on the way in, without the need for a tape measure.

Please not the following message from Mike for details on the line and current conditions in Porth yr Ogof:

"On the 8/10/2015 on a trip to sump 8 and 9 in Porth yr Ogof we took the opportunity to fit distance marker tags on the line approaching the visibility disc. You now do not need a tape measure to work out the distance from the disc. 
From 5m back every 1m is marked with a line arrow, every 50cm is marked with a white cable tie and every 25cm with a red cable tie. So by counting the tags from the point you can see the disc until reaching the disc you now know what the distance is. Other work done was relining of sump 8 and 9. 
I would suggest the reservoir upstream of the cave has released a large volume of water recently as the line upstream of four ways junction was completely buried in sand and had to be dug out for around 10m distance. Also several line Belays found to be broken and a repair was made. I hope it was the same flood pulse that damaged the belays. As a point of note it's good practise to carry some belays on dives to repair stuff ..." M.Thomas

Sump 8-9 Porth yr Ogof Upper cave.
Photo M.Thomas

If you are visiting Porth for a dive, please make sure that the reservoir are not planning to release water while you are in there! 
Mike reported that he saw NO trout at all - of any ethnicity - and it is presumed that they have simply been flushed out by the flood pulse (but not entirely sure how we could prove this).

As a result of flood pulses, some of the belays have been destroyed. If you are diving here please make any repairs if you are able to, as it all helps facilitate a clean exit in low visibility conditions (that diver may be you!)

We are experimenting with a aide memoire sheet which Rupert Massey used to good effect recently. He came back with a very comprehensive set of data for the project. To download your copy, click here:

Project Baseline South Wales Caves (PYO) aide memoire

Mandatory post-porth icecreams.
Photo M.Thomas

It is advised to contact Welsh Water 0800 0520145 to find out the dates and times of when they plan to release water from the reservoir as it seems that the flow in Porth increases significantly, with sand some 10cm deep being found in a normally clean washed side passage (on approach to Esser's passage). 

"Dwr Cymru Welsh Water is carrying out essential investment works at Ystradfellte reservoir and dam. Between June and October, we may occasionally need to release some additional water from the dam, which could see an increase in river levels. We do not expect the levels to increase significantly but would ask that people undertaking any recreational activities in the local river and caves bear this in mind when planning their activities. Dwr Cymru Welsh Water does not accept any liability in respect of any of these activities. These activities are 
carried out entirely at the individual's own risk."