Why did we do this?

The plant in the photo is an Obedient Plant that I rescued from a rain garden that was being dug up, due to construction, at the church where it was located.   I'm hoping it will survive until September when we will be planting our baby plants and rescuees. I've been working alot of overtime lately and neglecting to write about the Rain Garden.  We are in somewhat of a holding pattern right now, until September, in terms of activity.  I was asked to post about my motivation for installing the Rain Garden.   The obvious answer is that our back yard gets very sodden with heavy rain and  when the soil gets saturated the water seeps in through our foundation into our basement. 
I have always been interested in eco-friendly approaches to doing things.   I give my mother credit for this as she is a birder, an amateur botanist, and an all-round lover of nature.  She is also feisty and speaks her mind about issues that involve destruction or degradation of natural areas.  I absorbed all of this as I was growing up.  At some point, several years ago, I became aware of a group called "Wild Ones", which is an organization that encourages landscaping with native plants.  Through Wild Ones, I became aware of the work our landscape architect, Marcus, had done on a house in Elmhurst and spent alot of time looking over the web site that he put together about it,  fascinated by the possibilities for managing water in an environmentally friendly way. 
Long story short - We got in touch with Marcus and asked if he could work with us, given that we have a fairly limited budget, and he was willing to do so.   He very carefully looked over the situation with our house and yard, had me do water-absorption research in the front and back yards, then recommended that the first step would be to establish a rain garden that would allow us to route the water coming off the roof from the back to the front yard.