Thank you for your information request on planning a swimming pond.  There are numerous considerations including siting, water source(s), size and shape, permitting and management. 

I assume you have a site in mind for your pond.  The best water source for a swimming pond is groundwater – so avoid siting your pond where there will be a stream or surface runoff coming into it.  To determine if the soils at your site will hold groundwater I recommend getting a back hoe in to dig a small hole deep enough that you have standing water in it – then watch that water level for a year to see how much it fluctuates.  Will you even have water in this pond during the hot, dry months when you want to swim?

Swimming ponds should be fairly steep sided except for your access/play area.  Steep slopes into the water restrict submergent aquatic plant growth and provide open water.  Shallow ponds where light can penetrate to the bottom allow aquatic plant growth all the way across the pond.  Emergent aquatic plants growing around the edge of your pond is a positive for bank stability and habitat for frogs, etc.  Swimming and fishing are compatible pond uses.  Even if you don’t want to manage for fish I recommend this $4 MSUE bulletin  http://shop.msu.edu/product_p/bulletin-e1554.htm as it provides good pond design guidance. 

If your site is within 500 feet of a lake or stream or within 1000 feet of a Great Lake you will need a Part 301 Soil Erosion permit from your county prior to construction.  If it is near a wetland you will need a Part 303 permit from the MDEQ.  Search on www.michigan.gov/deq for these permit applications.

A buffer of native plants around the pond’s shoreline will provide stability and habitat. Closer to the water’s edge you should choose rushes and sedges for their rhyzonimous rooting to hold soils.  As you move upland in your buffer design you can go from wetland to upland plantings.  You can find a list of suggested native shoreline plants on the website of the Michigan Natural Shoreline Partnership (MNSP) www.mishorelinepartnership.org

The less turf grass you have around the pond the fewer problems you’ll likely have with Canada geese.  Also, turf grass clippings blown into the water contribute nutrients which can lead to overgrowths of aquatic plants.  (Same goes for leaves falling from deciduous trees.)  Install turf grass for mowing to the water’s edge in your access area only.

Submergent aquatic plants are important in a pond ecosystem but can take over quickly.  They will most likely come in with birds so don’t purchase or transplant (the latter is highly illegal).  When purchasing any plant for your pond avoid non-native, possibly invasive plants sold at big box stores (no matter the label).  Do your homework with the MNSP plant list mentioned above, purchase according to scientific name, and purchase from a MNPPA member www.mnppa.org.

A buffer strip of native plants is like a perennial bed and requires maintenance – especially in the first few years so keep that in mind when designing.  There are additional design helps on the MNSP website under Library.

Best wishes with your pond endeavor and thank you for asking these questions before you start the project!!!    Jane Herbert, MSU Extension