Waukesha County


Why build a rain garden? 
  • Water that soaks in replenishes groundwater and helps prevent flooding
  • A rain garden protects water quality by trapping sediment, fertilizers and other pollutants
  • Restore our natural hydrology allowing more water to soak in and less water to run off
How Can You Have a Rain Garden? 

All the information you need to site and design a garden is found in the Rain Gardens: A Guide for Homeowners and Landscapers. Once you have a plan in place, select the plants for your garden. Choose plants by height, bloom time, color - whatever your preference.

A typical rain garden: 
  • Is a sunken garden 4-8 inches deep
  • Has a flat bottom
  • Is 1/3 the size of the area draining to it - usually 75-300 square feet in size
  • Can be formal or informal in design
  • Drains within two days, so it does not provide breeding grounds to mosquitoes
  • Is planted with native plants to better infiltrate the water.

Why use native plants? 
  • With roots growing down twice as deep as the plants are tall, native plants are very efficient at absorbing water.
  • Also, each year, 1/3 of the roots die, providing deep tunnels for water to filter into the ground.
  • Rain gardens need no additional fertilizer and little pesticides
  • Native plants provide food and shelter for butterflies, song birds and other animals

The DNR has a listing of Native Plant Nurseries.

Schools may be eligible for free native plants for rain garden projects at your school site.  Email us to see if your school is eligible!