Capturing rainwater to replace irrigation water for landscapes: rain harvesting and rain gardens

Abstract

Capturing rainwater and using it for landscape watering needs is a reasonable and realistic way to reduce the use of potable water for landscape irrigation. This option has until recently not been given much consideration in humid climates such as Georgia. However, today water conservation is a critical issue for Georgia’s growing population. For many irrigated landscapes, harvesting of rainwater is a valuable alternative. An irrigation system coupled with a rain harvest system provides a source of irrigation water for all but the longest dry periods, and it reduces the amount of stormwater that moves offsite. Capturing stormwater during a storm and holding it on site to be used later for irrigation has many advantages. In Georgia, enough stormwater can be captured to significantly reduce or eliminate the need for potable water use in landscapes. Harvesting and storing rainwater for irrigation uses is only one method to make better utilization of rainwater for landscapes. Rain gardens and bioretention areas are intentional low areas where runoff water from impervious surfaces is diverted and contained so that the runoff will infiltrate into the soil. Rain gardens are most often a feature in a residential or small landscape. The purpose of a rain garden is to create a more natural flow keeping stormwater on site to infiltrate and reducing the amount of stormwater that runs into streets and storm drains. Bioretention areas serve a similar function to rain gardens but tend to be located in larger commercial landscaped settings. They collect rainwater from roofs of commercial buildings and/or parking lots.