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Water Planning & Distribution

Stretching Every Drop

Click the Fluent Water Facts below to learn more about Colorado water law.

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Water is not an unlimited resource. If too many people wish to use water from a source, it can become overappropriated. A watershed, stream segment, or aquifer is considered overappropriated if there is no remaining water available to fill new appropriations without causing injury to existing water rights.

Water availability must account for the natural water supply available from year to year and existing obligations, including the amount already claimed by senior water rights and interstate compacts.

By the late 1960s, if not before, it became apparent that the South Platte, Rio Grande and Arkansas rivers within Colorado were reaching overappropriation status. This spurred increased use of groundwater, conservation, reuse of imported water, change of agricultural rights to municipal use, water exchanges, and augmentation plans.


A water exchange can occur within the prior appropriation system. An exchange allows an upstream diverter to take water a downstream diverter would otherwise receive, if the water is replaced at the time, place, quantity and suitable quality the downstream diverter enjoyed before the exchange.

Augmentation Plans

An augmentation plan is a court-approved plan designed to protect senior water rights, while allowing junior water rights to divert water out of priority and avoid State Engineer shutdown orders.

Augmentation plans are required for diversion of water when there is no unappropriated water available, in all watersheds that are overappropriated during at least part of the year. These plans allow for out-of-priority diversions by replacing the water that junior water users consume. The replacement water must meet the needs of senior water rights holders at the time, place, quantity and suitable quality they would enjoy without the out-of-priority diversion. Replacement water may come from any legally available source and be provided by a variety of means. Some augmentation plans use storage water to replace depletions. Others include the use of unlined irrigation ditches and ponds during the non-growing season to recharge the groundwater aquifers that feed the river.

Applications for augmentation plans must be filed with the regional water court.

Return Flows

Return flows are water that returns to streams, river, or aquifers after it has been applied to beneficial use. Some examples of return flows include: water that percolates below the roots of a crop and into shallow groundwater, water seeping from unlined ditches, or discharges from wastewater treatment plants. Return flows are important for satisfying water rights downstream and delivering water for interstate compacts. They also provide instream flows, the water left in streams and other water bodies to preserve the natural environment to a reasonable degree.

Water Origin Resources

The Citizen's Guide to Where your Water Comes From explains how weather patterns and aquifers supply the water we use. Learn more about the intricate distribution systems Coloradans have developed to deliver water to our farms and cities.  Flip through the online version or purchase a copy.

Citizen s Guide  4a40f4c93383c

The Citizen's Guide to Colorado's Transbasin Diversions highlights the history, costs and benefits of these controversial water projects, from both an historic and current point of view. Flip through the online version or purchase a copy.

Transbasin Diversions


1750 Humboldt Street, Suite 200
Denver, CO 80218