Boulder Canyon Operations Office

Lower Colorado River Water Delivery Contracts

Questions and Answers

What is a Colorado River Water delivery contract?

A water delivery contract is a written agreement between the United States, through the Secretary of the Interior or his/her duly authorized representative, and another person or entity that authorizes the use of Colorado River water. The Boulder Canyon Project Act mandates that no person can divert or use water from the mainstream of the Colorado River except by a contract with the Secretary.

Water rights established by section 5 contracts are also referred to as “entitlements.” An entitlement authorizes a user to beneficially use mainstream water once (i) a decreed right, (ii) a contract with the Secretary of the Interior, or (iii) a Secretarial Reservation of Mainstream Water is obtained.

A “decreed right” is a right to use water defined by the U.S. Supreme Court Decree of 1964. The right, which must have existed prior to June 15, 1929 (the effective date of the Boulder Canyon Project Act), is also referred to as a Present Perfected Right. The 1979 Supplemental Decree of the U.S. Supreme Court in Arizona v. California lists and quantifies these Present Perfected Rights.

A “Secretarial Reservation” means water rights created by the Interior Secretary for the use of Federal establishments under Federal law. Examples of secretarial reservations are mainstream water rights reserved for National Wildlife Refuges and certain public lands administered by the Bureau of Land Management.

All Colorado River water delivery contracts in the Lower Basin are for permanent service. The form and content of these contracts have evolved since 1929 to reflect state-of-the-art technology to schedule and account for water use. For example, some water delivery contracts describe the water right in terms of an annual diversion right, and some contracts describe the water right in terms of a consumptive use right.

A “diversion” is an action that removes water from the mainstream or causes increased evaporation losses through an expansion of the surface area of the mainstream. The diversion may be (i) surface water that is moved through a turnout structure or drawn from a pump in the river, or (ii) water drawn from the mainstream by pumping groundwater.

Consumptive Use

The “consumptive use” of Colorado River water is the difference between the amount of water diverted and the amount of water that returns to the mainstream from that diversion after the water has been put to beneficial use. Water that is diverted and used by riparian vegetation before it can return to the Colorado River is accounted for as consumptive use that is charged against the diverter’s water entitlement. Water that is not diverted before it is used by riparian vegetation along the river is accounted for as system loss and is not a consumptive use.

Beneficial Use

“Beneficial use” means that water may be used only for beneficial purposes. This concept is established in section 8 of the Reclamation Act dated June 17, 1902 which defines beneficial use as the basis, the measure, and the limit of the right to use Colorado River water.

In early settlement of the West, when there were no laws governing the use of irrigation water, a new doctrine for water use known as “Beneficial Use” was implemented. Under this doctrine, no one could procure rights to more water than they could put to beneficial use. Thus, in terms of water rights, beneficial use was declared to be “the basis, the measure, and the limit to those rights.” A landowner had to divert water from a stream and put it to beneficial use continuously in an economic activity in order to claim and maintain water rights.

Today, Colorado River water is considered to be a public resource. Individuals, businesses, and public agencies may obtain a right to use water for beneficial purposes, including agricultural, domestic, municipal, commercial, and flood control. Over time, statutes and court decisions have recognized that beneficial use can also include fish and wildlife protection.

For a complete listing of entities with contracts for Colorado River water, visit the Lower Colorado River Water Entitlements web page.


Return to Water Delivery Contracts main page.


For more information on water delivery contracts and entitlements, contact Margot Selig

Last Updated: 6/4/15