The potential loss of Lake Lanier as a potable water source for metro Atlanta has spurred an intense search for new sources and new methods of water conservation. The recently passed Georgia Water Stewardship Act and the Governor’s Water Contingency Planning Task Force adopted a multiprong approach, seeking new sources of water as well as measures to enhance conservation, efficiency and data collection for the use of existing sources. Yet part of the solution that has received little attention is the use of rainwater harvesting, or catchment.
Rainwater catchment is as old as human civilization. Most of us are likely familiar with rain barrels — simple devices used to capture and store the rainwater output from the gutters on our homes, which is then used for irrigation. Potable rainwater systems are similar in theory and simplicity. They collect rainwater in the same way, capturing it as it runs off of roofs or other hard surfaces as a supplement to municipal water, but with an advanced filtration system. This filtration cleans the water to a level that equals — if not exceeds — the cleanliness and purity in municipal water systems. The catchment systems are simple, can be relatively small in size and can provide enough water to reduce the typical household user’s municipal water consumption by as much as 80 percent.
Such systems are already used in several states and foreign countries, but not yet in Georgia. While Georgia allows for rainwater catchment for nonpotable uses, such as irrigation, state and local building and plumbing codes do not yet allow for the permitting of such systems for potable use. Yet success with potable rainwater catchment is already being experienced in cities, such as Portland, Ore., and others throughout Texas. Experts from the American Rainwater Catchment Systems Association are currently working with the city of Atlanta to amend its building and plumbing codes to allow for the use of rainwater as a potable water source in residential and commercial buildings. If successful, Atlanta would join the vanguard of communities implementing this water solution.
While the initial investment can now cost upward of $12,000 to design and install a household system, attractive financing options exist to help make potable rainwater harvesting a reality until the law of supply and demand makes them more affordable. Gov. Sonny Purdue recently signed into law Georgia’s Property-Assessed Clean Energy, or PACE legislation. It allows local development authorities to provide financing for water conservation improvements where the financing is repaid by a special property tax assessment on the improved property. Georgia joins 19 other states with PACE legislation, which places potable rainwater catchment systems within reach of a greater number of people without a substantial net outlay of government funds. Georgia also recently enacted HB 1069, which allows a tax credit of 25 percent, or $2,500 of the cost of certain energy efficient equipment, including rainwater catchment systems.