Q: I read that it is against the law to catch your shower water and reuse it to water plants or to catch rainwater in buckets. That seems pretty ridiculous, especially during a drought. Any truth to either one?
A: Probably not. When you see such statements, even if they come from sources within the Colorado government, take them with a grain of salt. Usually such remarks are just speculation based upon personal opinions, or in this case probably personal interpretation of some recent Colorado Supreme Court rulings such as the Trinidad case.
Remember, quoting water law principles in the abstract is a bit like arguing religion and doctrine. Legal maxims can be found to support just about any position. But let me share with you the legal points that have won in the fiery crucible of water court in the past and I believe would be applied to your two examples.
In support of the two statements that you mentioned are a ton of old legal chestnuts. For example, once water starts running down a crop row, it cannot be reused because it has rejoined the sheet of surface water and thus is available for the next water user under the prior appropriation doctrine. Thus, only one chance is allowed to use the water. A hard reading of the recent Trinidad case would tend to add support to this old legal gem.
Concerning the "prohibition" against the "reuse" of shower water, that rule might be applied to "domestic water" (arising on the east side of the continental divide) but not necessarily to "foreign water" (transmountain diversions). Would the water court want to take the time to sort through that issue for all of the bathers and shower users in Colorado?
Additionally to prohibit a second use would void many of the agricultural and conservation practices that are currently being used.
I would submit for your consideration the argument that seems to resonant in water court. Unless restricted by the rules of the water provider, and as long as possession is not lost (flows beyond your property line), catching shower water for reuse would be permitted, provided that it is caught before it enters the house drainage system.
But what about the rules concerning the use of water for a different purpose? Our constitution gives us three basic use areas (domestic, agricultural, and industrial) with another emerging (recreational). In my opinion as long as the second use by a consumer obtaining water from a municipal provider does not cross those lines, it would be easy for the water court to permit the reuse of water for domestic purposes as long as possession is not lost. Otherwise, would it be "legal" for someone to drink the water in which vegetables were boiled? Or wash a car on the lawn? Now if the water was used to irrigate fruit trees where the fruit was sold, that would be different because the second use crosses constitutional lines.
As for catching rainwater, Colorado has a long history, especially for homesteaders in eastern Colorado, of upholding such limited domestic use. And anyway rainwater is not decreed, so if this example of possible illegal use of rainwater should ever be prohibited by the courts, what about rainwater that falls on a lawn or on farm crops?
Although the state has the right to proscribe procedural steps, limits, and even fees. My prediction is that the courts will not draw such a hard line and will permit limited domestic use of catching rain water in a barrel by an individual and distinguish such activities from cases involving water that flows across land. Our 145 year history, constitution, and water law can certainly support such a use.
Through the years it has been my observation that the water courts, for the most part, do try to apply common sense, straight forward, logical rules as opposed to trying to draw absolute rules and fine lines, especially if presented with these kinds of fact patterns. Given the choice between practical solutions vs. trying to determine how many angels can dance on the head of a pin, I would opt to be on the side arguing common sense in water court. At least so far, that normally seems to have been the more persuasive tactic to take.
Instead of spending time and energy disseminating these hypotheticals for either attempted amusement or as a show of supposed knowledge of law, I wish that practical common sense approaches grounded on a basic understanding of the reasons for various water law principles would be used to solve our real concerns -- water storage and the future of most of our interstate compacts.