Well let me see if I can help you Jim.
Let me guess. You clicked my link to the SSE website and got the SSE Coire Glas Hydro Scheme page OK?
So you got to this page - http://www.sse.com/CoireGlas/
Then on the SSE Coire Glas page maybe you clicked "Find out more about the Coire Glas hydro scheme"
Which should have taken you to the SSE Coire Glas Project Information page - http://www.sse.com/CoireGlas/ProjectInformation
Then on that page there is a list of Adobe PDF download links and it was with those you had a problem?
Here's the "Figure two scheme overview" link.
Now if you just click it, your browser may or may not have a Adobe add on which can display PDF files. If your browser doesn't have the add-on installed you might have problems with an ordinary click.
The better way maybe for you is to download the PDF file first then see if you can view it.
To download a file from a link, for example with Internet Explorer browser, Right-click the link and select "Save Target As..".
I think all computers and browsers can download files from links if you know how.
So download the PDF file to your PC and then you can view it assuming you have Adobe Reader installed. If you don't have Adobe Reader installed, no worries, because it is free and you should get it because it is very useful to have working on your PC for situations like this so you can download Adobe Reader from the Adobe website. http://www.adobe.com/
The water is sourced from a Scottish lake, only we call them "lochs", and this one is called "Loch Lochy" which is shown on the far right of this map I posted above.