This pump > Link is situated in a small children's play area at the eastern end of Wensum Park. It bears the maker's name "Allweiler" > Link and "Made in Germany" > Link and the number "75". The oldest German pump manufacturer, founded in 1860, Allweiler GmbH today is the European market and technology leader in fluid handling solutions for shipbuilding, power generation and special industrial applications.
I think the path you are talking about is Marriott's Way - running from Norwich to Reepham on the course of an old railway. It's part of National Cycle Route 1 (Harwich to Hull).