It sounds okay, but I prefer Brook/Brooke because it sounds softer. I don't mind nature names. It sounds like a plural/possessive noun, so that might be confusing in conversations.
But I don't think its a big deal. I believe that people don't usually say the word 'brook' unless they're interested in nature. Everyone says river or lake though, out of habit, especially for location names. (
Lake Erie,
Lake Ontario; Amazon
River, Indus
River, etc.)
Its a good nickname for
Brook, too. It sounds manly. I prefer it to Brookie, which is usually given to girls named
Brooke. I don't like the -ookie in the name. I think it sounds rough.
All in all, 7/10.