Merging urls of the same site

Okay so here’s the problem

I have two major domains that I’m working with
monterey rainwater. com and monterey graywater. both .coms

This issue is with Monterey rainwater

Somehow is listed with the search engines under three different names

monterey rainwater. com

www.monterey rainwater. com

And http://www.monterey rainwater. com

the spaces in the urls is to comply with forum rules about how many urls may be present in this question

To further complicate things I have the website www.monterey

This website has a folder that contains an exact copy of the Monterey rainwater website.

I would just delete this folder but this copy is the one that is listed well with the search engines

So I’m just trying to combine them all so that Monterey graywater is its own site and all the different versions of Monterey rainwater are merged into one without losing my search engine ranking

@daveslite I think 301 redirects are what you want. This link should get you started in the right direction.