Good Morning Kathryn, 

Thank you for contacting the U of M Extension Service. 

Based on your description of the hill, you have a great spot to do a pond or rain garden. 

Since you live in Scott County, here is a link to the Scott County Soil and Water Conservation District: https://www.scottswcd.org/tacs-program

I believe this would be considered a conservation project and they provide technical assistance and would do an on-site evaluation of your location. Depending on your project, they might have grant funding to assist with the costs. 

Here is also a link to building a rain garden if this might apply to your site: https://extension.umn.edu/landscape-design/rain-gardens

Here is a link to the Minnesota Water Garden Society: https://mwgs.org/

You might consider creating a landscape to support pollinators and other wildlife (frogs): 

https://extension.umn.edu/lawns-and-landscapes/flowers-pollinators

Our pollinators are dying at an alarming rate and can use all the wild landscapes we can provide. 

Good Luck!

You are welcome!