Laws Inconsistent in Their Support of Rainwater Harvesting

Tucson Breaks New Ground With Proposed Water Harvesting Law

Due to the complexity of water law, seemingly simple solutions often end up not being so simple after all. A case in point is rainwater harvesting, a method to concentrate and collect rain falling on house and grounds for direct use and storage. Free, literally falling from the sky, rainwater can augment domestic water supplies.

The law of gravity, however, is not the only law affecting the harvesting of rainwater. Other laws also apply. For example, laws from two different locations, one in effect in Colorado and the other proposed in Tucson, take much different approaches to rainwater harvesting, one essentially forbidding the practice and the other requiring it. Together, the two laws provide an interesting case study of different views of water harvesting.

A person wanting to harvest rainwater in Colorado faces a rather formidable barrier in state law. The doctrine of prior appropriations with its mantra of "First in time, first in right" rules and determines surface water rights. This means that senior water right holders, those who first put water to beneficial use, have priority water rights in the now overly appropriated rivers. In the event of shortages on the river, their rights are satisfied before junior water right holders.

Prior appropriation does not disallow water harvesting; nor does the Colorado state constitution which allows the right to divert the ?unappropriated waters of any natural stream.? Problems arise, however, with the Colorado Supreme Court?s rather broad interpretation of the term ?natural stream.? That, along with the presumption that the flow of all diffused water ends up in groundwater or streams, complicates rainwater harvesting efforts in the state. A person harvesting rainwater is, in effect, diverting water from those with more senior rights to it.

(Other states have definitions more accommodating to rainwater harvesting. Also a prior appropriations state, New Mexico, for example, considers roofs as an artificial surface while water running downstream flows on a natural surface.)

A June 6 article in the Denver Post provided a case study of the state?s regulatory approach to water harvesting. A woman living in a solar-powered home in rural Colorado makes ends meet by growing organic food for sale. She applied for a water right to collect rain running off the roof of her house and greenhouse to water her crops. The state engineer opposed her application arguing that her roofs were ?tributary? to the San Miguel River and that her water gain from roof runoff could result in a water loss to senior water right holders on the river. The state water court agreed.

She could harvest rainwater for her garden, however, if she developed an augmentation plan and provided proof to the state engineer and water court that she would release to the stream the same amount of water she captured to grow her vegetables. Further, an engineering analysis would need to be done ? she would pay for it ? to demonstrate that her augmentation water would be released to the river consistent with the natural cycle.

Washington state appears to have an ambivalent attitude about rainwater harvesting. Technically harvesting runoff from a roof is illegal since the collected rainfall is considered a resource of the state and is regulated as public waters. Despite the legal restrictions, however, state officials have allowed homeowners to harvest small amounts of rainfall.

State officials are more concerned when large amounts of rainwater might be harvested, although the threshold between acceptable and illegal amounts has not been defined. This uncertainty has discouraged collection projects in the state. To reassure potential rainwater harvesters, Seattle obtained a citywide water-right permit enabling its citizens to legally collect roof runoff in most areas of the city.

Compared to the above states, Tucson is taking a more determined approach for encouraging rainwater harvesting. Up for an Oct. 14 vote by the City Council, a proposed law would mandate water harvesting for landscaping on commercial properties including most apartment complexes. Per the proposed law, beginning June 1, 2010, when the law would go into effect, new business premises must have plans to install systems to harvest rainfall. Further, within three years of legally occupying the premises, at least 75 percent of the water used for landscaping must be water harvested by the system.

The proposed law has raised concerns among developers. In response to such concerns, a July 22 meeting conducted at Tucson Councilman Rodney Glassman?s office provided an opportunity for developers and others with questions and concerns about the law to meet with city staff. About 60 people attended the meeting.

Concerns raised at the meeting included cost: some feared that installing a rainwater harvesting system will add significantly to the cost of a building. Aesthetics also was a concern with some questioning whether rainwater harvesting systems with cisterns and large basins could be attractively worked into a building design. Questions also were raised about having to meet the 75 percent quota of harvested water on landscaping during times of drought.

If the lively exchange did not end with the issues decidedly settled, it did demonstrate that the proposed law has attracted broad community interest.

Val Little, director of the Water Conservation Alliance of Southern Arizona (Water CASA), believes the proposed Tucson law is taking an innovative approach to rainwater harvesting. She says, "It is setting performance-based goals by saying you will get 75 percent of your landscaping irrigation from rain. ... This is a very creative way to set up requirements because it offers landscape architects, designers and engineers the opportunity to come up with unique solutions that match the site. So you could say [the proposed law] is very forward looking and unique in the nation."

But, at the same time, Little says Tucson?s action is not particularly unique in that efforts are underway all over the country to remove obstacles to the harvesting of rainfall. Tucson is taking a prominent place in that growing movement.

The state of Arizona also has a rainwater harvesting strategy, its approach differing, however, from Tucson?s efforts at the local level. Rather than a legal mandate, the state relies on economic incentives, offering taxpayers a one-time tax credit of 25 percent of the cost of a rainwater or graywater system, up to $1,000. Builders plumbing new residences to capture all graywater sources are also eligible for an income tax credit up to $200 per residence.