Talk:Cardiff Corporation Waterworks

Llanishen Brook and megalitres

Hi Bob1960evens - nice piece of work, thanks for an excellent addition to WP. Two observations if I may: i) in this line - Works included a storage reservoir at Lisvane, with a catchment area of 2,200 acres (890 ha), collecting water from the Llanishen, Nant Mawr, Nant Draw, Nant Felin and Nant Dulas. - are you referring to Llanishen Brook?, and ii) I puzzled over the storage capacities initially before realising that 'MI' is in fact 'Ml' (yes, looks the same in this font! - but one is a capital 'i' and the other a lower case ell) and is the result of the automatic conversion into Megalitres. It's a WP-wide issue but might MI be explained on first encounter to avoid puzzlement of other readers? cheers Geopersona (talk) 07:58, 15 September 2020 (UTC)

Hi Geopersona. Thanks for the observations. I have now used 3 million imperial gallons (14 megalitres)(Ml) on first occurrence. I am not sure about Llanishen Brook. Wheatley only calls it the Llanishen, and I cannot find anything labelled Llanishen Brook either on the modern 1:25000 map or on historic 1:2500 maps. Bob1960evens (talk) 23:27, 20 September 2020 (UTC)

Hi Bob1960evens - if you take a look at https://maps.nls.uk/view/135197707 then a stream which runs off the southern edge of the sheet is labelled Llanishen Brook at that point and is almost certainly what Wheatley had in mind, though there's a judgement as to whether we stick strictly with the reference or make a reasonable inference, I guess. cheers Geopersona (talk) 10:25, 21 September 2020 (UTC)

Hi Geopersona. I have looked at the map, and managed to find the same brook on old-maps, so I can relate it to where it occurs on the modern map. I am unsure whether it is the same, since it appears to be too far west to feed a storage reservoir in Lisvane, although I suppose it is possible that Lisvane described a much larger area than it now does. I wonder if a more precise location for the reservoir is documented anywhere? Having said that, I have just re-read the article, and it says that pipes were laid from intakes on the various streams, so perhaps too far west is not a problem after all. Bob1960evens (talk) 22:03, 21 September 2020 (UTC)

Purely speculation on my part(not in itself good enough!), but looking at the maps, I'd have thought that a diversion (by pipe) of the headwater stretches of the Llanishen Brook into the Nant Transyrhebog tributary of the Nant Fawr would make a lot of sense, given their separation of only half a mile in the Thornhill area. Of course, Welsh Water would know. cheers Geopersona (talk) 06:32, 22 September 2020 (UTC)