Picking the Right Location
The best locations are in natural depressions or low lying areas where water flows naturally from a downspout, driveway, patio or sidewalk. Avoid steep slopes and areas near septic systems or drinking water wells. You must be able to move water from the hard surface (roof, etc.) to the garden location, either by directing a downspout with an extended tube towards it, or simply by following contours and capturing water that is naturally flowing downhill.
The garden must:
- Be at least 10 feet away from foundations and utilities.
- Have well-drained soils. A rain garden is not designed to be wet all of the time. You want it to fill during storms and then have all of the water infiltrate over the next day. Infiltrating water within a day after a storm will prevent mosquitoes from breeding in the standing water.
To test your soil, dig a small 6-8 inch deep hole and fill it with water. If it drains within 6 hours, you have a good site. If it takes longer you may need to adjust your soil content by adding sand and compost or find another location. Here is a short video on soil testing that might be helpful.
- Be large enough to handle the amount of water it will receive. There are several online tools to help calculate the right size based on the area being drained to the garden, including a calculator and a map based tool.
- Be positioned so that overflow during large storms will move away from your house.
For more information to guide you through the rain garden creation process, consider downloading the free Rain Garden app
(for iPhone and Android) developed by the University of Connecticut.