Try and get your hands on a copy of the 'Waterside Wirral' book, produced by the Mersey Basin Trust. It's full of maps, photos, and info etc., on Wirral's waterways. Ask at your local library if you can't find one in the shops. Seem to think it use to sell for something like a fiver.
Anyway, failing that, see if the Greg Dawson books say anthing about it. His book on Arrowe might be a good starting point.