Water Law: Frequently Asked Questions

  • Q. Does Denver Water sell water to other states, such as California?

    Denver Water does not sell water outside the state of Colorado. No one else sells water to California either, because it is not permissible to sell Colorado’s water outside the state.  

    The water that flows from the Colorado River to California was allocated under the 1922 Colorado River Compact, which is an agreement among the upper basin and lower basin states about how to allocate water in the Colorado River. Each state was allocated a portion of the river’s flow, and those states that did not take all the water they were entitled to had their rights preserved forever. (Normally, under western water law, if one doesn’t use the water to which he/she has rights, those rights can be taken away.)

    Because Colorado didn’t have enough demand in 1922, it did not (and still does not) take its entire share of water to which it was entitled. California, however, has taken more than its share for many years. Recently, the U.S. Department of the Interior moved to stop California from taking more than its share. That water is being held in a reservoir on the lower Colorado River now. The compact was affirmed by Congress and is a part of federal law now. It can only be terminated by an act of Congress and with the unanimous consent of the compact states.

  • Q. Why can't Denver Water customers reuse their own graywater for outdoor use?

    Under current Colorado law, graywater may be captured and reused only in areas where the local governments have adopted an ordinance approving the use of graywater. To date, the City and County of Denver has not adopted such an ordinance. That may change soon, however, with the recent passage of House Bill 1044.

  • Q. Can I collect rainwater?

    Capturing rainwater is an ongoing issue in Colorado, and it is not allowed under state water law. For the most part, Colorado law does not allow Denver Water customers to collect rainwater.

    In 2009, however, the Colorado State Legislature passed two laws that carve out exemptions from the general rule.

    The first law says that if you are not served by a domestic water system, such as Denver Water, and you are located in a designated ground water basin or your collection system qualifies as exempt from 37-92-602(1)(g)(I), you are allowed to capture rainwater for household, fire protection, stock watering and irrigation of up to one acre of lawns and gardens as long as it is applied to uses specified in the well permit that applies to your property.

    The second law allows the state to participate in a study of 10 new developments to determine the impact of capturing rainwater on streams, rivers and tributary groundwater.