Terryland River

snubbleste

According to todays Tribune, the stream flows from the Corrib at Terryland castle as far as Castlegar and then disappears underground at Castlegar before re-emerging at Lough Atalia and Oranmore.
Is this true?

I never heard this before, under whose grounds does it flow, why is it a secret etc.

Sponge Bob

snubbleste wrote: »

According to todays Tribune, the stream flows from the Corrib at Terryland castle as far as Castlegar and then disappears underground at Castlegar before re-emerging at Lough Atalia and Oranmore.
Is this true?

Yes, always was.

I never heard this before, under whose grounds does it flow, why is it a secret etc.

Under Ballybane Industrial Estate and The top of Doughiska then Roscam and out in Oranmore, the lough Atalia branch is small.

dilallio

http://www.castlegar-county-galway.com/the-sandy-river-terryland-river-castlegar-galway

snubbleste

Is that part of the town mostly limestone then?

jkforde

snubbleste wrote: »

Is that part of the town mostly limestone then?

Ya, see map from the GSI (http://spatial.dcenr.gov.ie/imf/imf.jsp?site=GSI_Simple)

Surprised to learn that it flows the other way, always presumed it flowed towards the Corrib! :eek:

I had wondered why the weir at Sandy Road went apparently away from rather than towards the Corrib.

joeKel73

jkforde wrote: »

Surprised to learn that it flows the other way, always presumed it flowed towards the Corrib! :eek:

From walking up to that damned post office place to collect parcels I'd noticed where it "came up" just behind Glenburren Park. I'm very surprised to hear it's flowing into the ground there.... that's uphill from Terryland surely... where's the GRAVITY people! The world's gone mad! :eek::eek:

(Image from Bing)

Sponge Bob

It goes DOWN at Glenburren FFS

muskyj

the river does indeed sink at glenburren, i work a stone throws away from the spot. interesting link to the castlegar info pages. from reading that site i have a question. whereas i had heard of coopers cave, have any of you heard of or know where the two mile ditch cave is?

joeKel73

Checked the elevation difference between the start at the corrib and the point where it sinks in Google Earth and it appears to go uphill 2m. I'm sure the accuracy of Google Earth's elevation values is worse than +/- 2m though.

Anyone got an ordinance survey map for the area? Still can't get my head around it!

JohnCleary

foto joe wrote: »

Anyone got an ordinance survey map for the area? Still can't get my head around it!

http://ims0.osiemaps.ie/website/publicviewer/main.aspx#V1,531198,727042,5

joeKel73

I was on there already, not enough detail on the levels, when you zoom to any detail it switches to aerial maps.

jkforde

See attached screengrab from OSI - I've marked on the 10m contour - doesn't seem to be much of an elevation difference to drive any flow! Is the stream's flow monitored down at the old waterworks? Curiouser and curiouser...

muskyj

was down by the two 'sinkholes' this week and they clearly flow underground. just interested if anyone knows the exact points they reappear above ground and pressumably down by the sea?

siltirocker

Just saw this now. IMO that's cool and im delighted i know that wee bit of info. Thanks guys.

Fuinseog

snubbleste wrote: »

Is that part of the town mostly limestone then?

city, galway is a city. the charter was granted by the king anno 1484.

Mrs OBumble

Whose king was that again?

Fuinseog

JustMary wrote: »

Whose king was that again?

our king. galway city was always loyal to the crown, something neither the uncouth element outside the city walls or cromwell could not appreciate.
staying on suject, I wonder would it be possible with sub aqua gear to swim along the river where it goes under ground.

bonzodog2

muskyj wrote: »

was down by the two 'sinkholes' this week and they clearly flow underground. just interested if anyone knows the exact points they reappear above ground and pressumably down by the sea?

I just went for a walk to look for the exit of one branch, didn't find it.
See this thread.

But I did find an exit of some stream, which could come from Terryland, but if you managed to get there from Castlegar, you'd either have to turn round and go back, or wish you'd brought oxy-acetylene cutting gear with you for the steel bars.

I never noticed much of a flow into the ground at Castlegar. (Been there twice recently, found the cave the 2nd time)

topper75

Fuinseog wrote: »

I wonder would it be possible with sub aqua gear to swim along the river where it goes under ground.

Catch 22 there. If your balls are big enough to try it, you won't fit through.

There are such people as cave divers but they are a rare breed. You operate in darkness. If anything goes wrong, you cannot just surface. Who would be willing to risk their lives to see what is in the underground section of the Terryland river?

jkforde

Emailed a researcher in NUIG about the Terryland and he replied...

"The entire area is classed as a regionally important karst aquifer and there are numerous large conduits in the limestone (which is pure bedded Burren formation). I would guess that the likeliest outflow is probably Lough Atalia rather than Oranmore. There is some structural control on the formation of conduits in limestone and certainly around Castlegar the dip of the beds is towards the city rather than Oranmore. While the dip is gentle it would have an impact on the orientation of conduits; coupled with the driving head for the water the might make flow from the east of the city towards Oranmore unlikely.
As for the river itself, the key elevations to record are not the groundlevels, but the water levels at the sink and the water levels on the Corrib. That is the head gradient that will drive the flow. The easiest way to do this is to survey the points in. Option 1: get a differential GPS unit and record the two elevations (this will give an accuracy of within +/- 10cm in the vertical); Option 2: get a tripod, level (theodolite) and staff and do a relative elevation survey. This is the cheapest, if slightly time consuming approach. If done correctly, however, it will give you an absolute reading of relative water heights, thus allowing you to work out the gradient."

So sounds like its outflow hasn't been tied down and the surface flow needs some techy surveying with expensive gear! (apart from just looking into the sinks to see which way it's flowing on any given day!)