Denton Fire Station

Rainwater Harvesting Policies Throughout the US

Denton Fire Station
Photo: “IWS -”; 5600 gallon commercial rainwater collection system for LEED Gold rated fire station in Denton, Texas. Rainwater is used to irrigate native plant landscaping around the station.

As battles over water rights rage and profligate water usage continues in many places, policy makers will have to find tools to lead communities towards more responsible water management.  One such policy tool is an ordinance to encourage or even require rainwater harvesting.

The best rainwater harvesting policies protect water as a human right, protect public health and promote sustainability. Through a combination of incentives, taxes and penalties, meaningful water conservation can be achieved.

Restrictive policies can create barriers to implementation and add unnecessary costs, but well-designed policies will encourage rainwater harvesting and help to maximize the benefits of implementing these systems. When developing a rainwater catchment policy or ordinance, consider the following criteria.  Your policy or ordinance should be:

•    Economically viable and ecologically sustainable
•    Achievable and measurable
•    Easy for the public to understand and simple to implement with streamlined processes
•    Reviewed by actual rainwater harvesting professionals
•    Include education and technical training for the public, staff and elected officials
•    Include financial support such as subsidies or grants for low-income communities

Semantics are also important to consider.  How you define rainwater can greatly affect outcomes.  Avoid classifying rainwater as stormwater, runoff, greywater or wastewater.

Hundreds of thousands of rainwater harvesting systems exist throughout the world.  While in many places in the U.S. rainwater harvesting is actually banned because of “first come, first serve” laws dating back a century, a few American cities actually require that new buildings use cisterns to store roof runoff.

Legislation around the U.S.:

Tucson, Arizona: In October of 2008, the city of Tucson, Arizona became the first municipality in the country to require developers of commercial properties to harvest rainwater for landscaping.  The new measure – approved by a unanimous vote by the City Council – requires that new developments meet 50% of their landscaping water requirements by capturing rainwater. The new rule goes into effect June 1, 2010.

Santa Fe County, New Mexico: Residences with 2,500 sq ft or more area must install an active rainwater catchment system comprised of cisterns. All commercial developments are required to collect all roof drainage into cisterns to be reused for landscape irrigation.

Albuquerque and Bernalillo County, New Mexico: Residences with 2,500 sq ft or more area must install an active rainwater catchment system comprised of cisterns. All commercial developments are required to collect all roof drainage into cisterns to be reused for landscape irrigation.

State of Texas: In 2001, the Texas legislature amended the Texas Tax Code to allow taxing units of government the option to exempt from taxation all or a part of the assessed value of the property on which water conservation modifications have been made.

City of Austin, Texas: The residents of the city of Austin can buy rain barrels at subsidized rates and also they can claim a rebate for the installation of approved cistern systems. Commercial/industrial properties can collect rebates up to $40,000 for the installation of rainwater harvesting and Grey water systems.

City of San Antonio, Texas: The San Antonio Water System’s (SAWS) will give up to 50% rebate on the cost of new water-saving equipment, including rainwater harvesting systems, to its commercial, industrial and institutional customers. Rebates are calculated by multiplying acre-feet of water conserved by a set value of $200/acre-foot.

State of Arizona: The Government announced a one-time tax credit of 25% of the cost of water conservation system (the maximum limit is $1,000) for its residents. The water conservation system is defined as any system, which can harvest residential grey water and/or rainwater. The builders are eligible to get the tax credit up to $200 per residence unit constructed with a water conservation system. Any citizen in this state who has purchased a water harvesting system on or after January 1st, 2008, can apply for the Arizona tax credit. There is roughly $250,000 per year allocated for these tax credits.

Legislation around the world:

Mumbai, India: The state government has made rainwater harvesting mandatory for all buildings that are being constructed on plots that are more than 1,000 sq m in size.

New Delhi, India: Since June 2001, the Ministry of Urban affairs and Poverty Alleviation has made rainwater harvesting mandatory in all new buildings with a roof area of more than 100 sq m and in all plots with an area of more than 1000 sq m, that are being developed.  Furthermore, the Central Ground Water Authority (CGWA) has made rainwater harvesting mandatory in all institutions and residential colonies in notified areas (South and southwest Delhi and adjoining areas like Faridabad, Gurgaon and Ghaziabad). This is also applicable to all the buildings in notified areas that have tubewells.

Haryana, India: Haryana Urban Development Authority (HUDA) has made rainwater harvesting mandatory in all new buildings irrespective of roof area.

Himachal Pradesh, India: All commercial and institutional buildings, tourist and industrial complexes, hotels etc, existing or coming up and having a plinth area of more than 1,000 square meters will have rain water storage facilities commensurate with the size of roof area. No objection certificates, required under different statutes, will not be issued to the owners of the buildings-unless they produce satisfactory proof of compliance of the new law. Toilet flush systems will have to be connected with the rainwater storage tank. It has been recommended that the buildings will have rain water storage facility commensurate with the size of roof in the open and set back area of the plot at the rate of 0.24 cft. Per sq m of the roof area.

Bangalore, India: In order to conserve water and ensure ground water recharge, the Karnataka government in February 2009 announced that buildings, constructed in the city will have to compulsorily adopt rain water harvesting facility. Residential sites, which exceed an area of 2400 sq ft (40 x 60 ft), shall create rain harvesting facility according to the new law.

Victoria, Australia: Since July 2005, new houses and apartments in Victoria must be built to meet the energy efficiency and water management requirements of the 5 Star standard, which requires either a rainwater tank for toilet flushing, or a solar hot water system.

South Australia: New homes are required to have a rainwater tank plumbed into the house.

Syndey and New South Wales, Australia: The BASIX (Building And Sustainability Index) building regulations call for a 40% reduction in mains water usage. In order to meet the BASIX target for water conservation, a typical single dwelling design must include a rainwater tank or alternative water supply for outdoor water use and toilet flushing and/or laundry, among other water conservation devices.

Gold Coast, Australia: Construction of 3,000-litre (800-gallon) rainwater tank is mandatory in the Pimpama Coomera Master Plan area of Gold Coast. This is for all homes and businesses centers connected to the Class A+ recycled Water system (those approved for development after 29 August 2005). The tank should be plumbed to their cold-water washing machine and outdoors faucets.

Queens land, Australia: Residents can get a rebate of up to $1,500 for the purchase and installation of home rainwater storages.

Germany: Rain taxes in Germany are a great example of internalizing externalities for a more fair system.  Fees are collected for the amount of impervious surface cover on a property that generates runoff directed to the local storm sewer.  That means that the more the rainwater is caught and conserved, the less rainwater runs off and is added to the storm drains. Less runoff allows for smaller storm sewers, which, in turn, saves construction and maintenance costs at the site. Thus there is a large incentive to convert impervious pavement/roof into a porous surface.

Rainwater catchment policy has implications not only for addressing water shortages, but also for reductions in energy use and related carbon emissions, as treating water consumes a lot of energy (in California, municipal water supply and wastewater treatment systems account for about 35% of energy used by municipalities.).  As local governments begin to face mandatory emissions reductions, saving water may become a cost-effective way to shave off carbon emissions that requires little capital investment compared with other strategies.