A Colorado Watershed

Constituents had been complaining, state senator Jim Isgar says. Water shortages are chronic throughout most of Colorado, so that municipal delivery systems have trouble satisfying demand. Yet collecting the storm water running off your roof to irrigate a garden or supplement the household supply made you a criminal. Enforcement personnel weren't seeking out offenders, Isgar insists, but if you were cited, a rain barrel set beneath your downspout could earn you a $500 fine. Two barrels, two fines. As chair of the Agriculture, Natural Resources & Energy Committee and a rancher, Isgar has experienced both the public and private aspects of this issue. He concluded that such a blanket ban on storm water harvesting didn't make sense. Legislation he sponsored and helped to pass this spring, Senate Bill #80, will make collecting storm water legal, at least in some situations. With carefully defined limitations, residential users who do not have access to a public water supply may now supplement or substitute such harvested water for the amount that state regulations would allow them to draw from a private well.
This may seem like a minor victory, but it is one environmental activists have been demanding for some time. They've ridiculed the ban as evidence of entrenched greed and bureaucratic backwardness.
In fact, it is better understood as a legacy of Colorado's system of water regulation, in which individuals and corporations can own rights to a certain amount of flow from a reservoir, stream or aquifer. These rights can be bought and sold, even leased or rented, and in most areas of the state, the flow is oversubscribed - when the Colorado Water Conservation Board began working to preserve the flow in environmentally sensitive streams and rivers, it had to purchase water rights in the marketplace. Harvesting storm water was prohibited because it was viewed as robbery. Your runoff nourishes a stream or aquifer, was the thinking, and if you divert that water, you're depriving someone downstream of the full flow to which they are legally entitled.
One key to the success of Senate bill #80 it that it respect this concept of water as private property. It limits the harvesting of storm water is to residential users only and even then the water obtained in this manner can be used to supply only defined purposes, such as fire protection, watering livestock or irrigating not more than an acre of lawn. A plan of any proposed harvesting system must be submitted to state engineers for approval before installation, and local authorities have the right to restrict storm water harvesting in their jurisdiction if they feel it necessary.
Another critical piece in the passage of this bill was a study commissioned by a number of water districts in Douglas County, midway between Denver and Colorado Springs. This found that on average only 3 percent of the moisture deposited by snow and rain actually reached streams or aquifers, and that the rest, 97%, was lost to evaporation. Bills passed by the state legislature more or less concurrently with Senate #80 have established pilot programs in various regions to determine at each site how much moisture storm water harvesting will actually divert from the public supply, with the plan that storm water harvesters will be required to feed an equivalent amount back into streams and aquifers at appropriate seasons.
A notable aspect of this very public battle over water use has been the hostility directed by citizen and environmental groups nationwide toward Colorado's system of water law. Owners of water rights have been branded as "water buffaloes" and a great deal of ink and bytes have been devoted to disparaging their monopolization of a resource that literally falls from the sky.
This seems outrageous, but arguably, it has had a beneficial effect. The tug of war over who owns what water has forced Coloradoans to face a fundamental truth. Water is not only a limited resource, but also a dynamic one that is always on the move throughout a vast cyclical web through the landscape, underground reservoirs and sky. The water buffaloes are correct in maintaining that wherever you tap this web, you diminish the flow throughout. Too often in other regions of the country, the various water sources are treated as discrete. When a local water utility restricts landscape irrigation to protect the public supply, homeowners drill wells, pumping down the aquifer so that streams and rivers run dry.
The test of Colorado's new right to water harvesting will be if the beneficiaries understand that what they have won is the right to become stewards of the public supply. Supporters of storm water harvesting rejoice that as many as 300,000 homeowners in Colorado will now have the use of the precipitation that falls on their roofs. If this water is used responsibly, it could provide real benefits. For example, it could be substituted in firefighting or essential household uses for some of what is currently being sucked from the state's oversubscribed aquifers and streams.
If, however, all these homeowners tap their harvest to plant the acre of lawn to which the new law entitles them, that will be an environmental tragedy. Turf grass cannot survive without constant irrigation in this arid region; maintaining 300,000 new lawns will drain trillions of gallons every week throughout the summer. As the water buffaloes could tell the new stakeholders, that water comes from somewhere and what you take, someone else, or the ecosystem, cannot use. Water may fall from the sky, but it's never free