30 SECONDS WITH YOUR MAYOR Building Codes & Rainwater Harvesting By the year 2050, the worldwide availability of freshwater will have decreased by a third as a result of global warming, population growth, and wasteful habits. 1 As a water conservation strategy, rainwater harvesting conserves water through the collection and storage of water for human use, and is easily implemented, replicable, and regulated. Another benefit of rainwater harvesting is a reduction in stormwater runoff and erosion. Building codes with provisions for rainwater harvesting promote water conservation and site management on a community scale. Could include local data on stormwater runoff rates and fees or water conservation statistics. PROPOSED ORDINANCE If not explicitly prohibited, rainwater harvesting and re-use within buildings is often not allowed. Rainwater harvesting policies should address several issues, including: Intended use of captured rainwater: harvested rainwater used for irrigation will not need to be as regulated as water that needs to be treated for consumption Scale of project: residential and commercial projects may have different requirements, largerscale projects may need more guidelines than smaller ones Process for permits: when permits are required, the municipality must stipulate the process for and requirements of individual permits Design and installation of system: including plumbing issues that may be associated with the project Water treatment requirements, if applicable BENEFITS The environmental benefits of rainwater harvesting are two-fold: water conservation and reduced stormwater runoff. Additionally, there are economic and social benefits associated with rainwater harvesting. Reduced potable water use (e.g. harvested rainwater use for irrigation and flushing toilets) Reduced stormwater runoff as less water runs off impervious surfaces into surface water bodies untreated, meaning fewer water quality, erosion, and habitat problems Improved soil quality through minimization of erosion. Reduction in utility demand Decrease in stormwater runoff fees, if applicable Promotes accountability in site management issues COSTS Estimated [Initial] Capital Investment: $25,000 + for commercial facilities; depending on the size of the program, a consultant can provide for $10,000 – 50,000. Often building code officials can research and propose their own amendments. 1 http://www.southface.org/web/resources&services/publications/factsheets/27_rainwater-recovery-v2.pdf WWW.SUSTAINABLECITIESINSTITUTE.ORG ©2012 The National League of Cities, All Rights Reserved 1 WWW.SUSTAINABLECITIESINSTITUTE.ORG ©2012 The National League of Cities, All Rights Reserved 2