Colorado Water History

A guide to finding and using historical information about water in Colorado and beyond

Carpenter and the Compacts

This virtual exhibit highlights the work of water lawyer Delph Carpenter in negotiating Colorado's river compacts. It is based on documents and photos from the Papers of Delph E. Carpenter and Family, a collection in the Water Resources Archive in Morgan Library at Colorado State University.

For more information about Delph Carpenter, read the biography Silver Fox of the Rockies by Daniel Tyler.

"Father of Interstate Compacts"

Carpenter at desk

Raised on an irrigated farm, Delph Carpenter recognized water as a precious resource in this arid land, something worth fighting for. Becoming a lawyer and establishing a practice in his hometown of Greeley, Colorado, Carpenter served many clients with water-related legal needs.

As the attorney for the Greeley-Poudre Irrigation District, Carpenter became lead counsel in the Wyoming vs. Colorado lawsuit after the District constructed a tunnel to divert water from the Laramie River. Carpenter argued the case twice before the U.S. Supreme Court (1916 and 1918). With other lawsuits on the way, including one filed by Nebraska concerning the South Platte River, he began thinking about out-of-court solutions to the West's water conflicts.

Carpenter conceived the compact idea, encouraged negotiations and then advocated for ratification by state and federal legislatures. During all this, he suffered from the onset of Parkinson's disease, becoming increasingly disabled and eventually bedridden from 1933 until his death.

Photo: Delph Carpenter at his desk in state senate, 1911.

Delph's Dates

  • 1877 - Birth in Greeley, ColoradoHoover letter
  • 1899 - Graduation from University of Denver Law School
  • 1901 - Marriage to Michaela Hogarty
  • 1909-1913 - State senator
  • 1911-1922 - Wyoming vs. Colorado case
  • 1922 - Colorado River Compact
  • 1933 - Removal as interstate river commissioner
  • 1943 - Honored by the National Reclamation Association
  • 1951 - Death in Greeley

Letter: Praise from President Herbert Hoover, 1929 (see p.33 of the PDF file).

Colorado's River Compacts

Colorado River Compact

Colorado is part of nine interstate river compacts, documents which govern the use of rivers crossing state lines. Key to equitable allocation of the West's most precious resource—water—the compact clause of the U.S. Constitution was first applied to rivers in the 1920s, an idea conceived and promoted by Greeley water lawyer Delph Carpenter.

The first and best example is the Colorado River Compact. A brief document—less than 2,000 words—the Colorado River Compact emerged after nearly a year of negotiations and gained ratification only after seven years of political debate. The Compact still proves contentious today as drought, growth and the environment affect western states and their water needs.South Platte Compact signing

Of Colorado’s nine compacts, Delph Carpenter had involvement to a greater or lesser extent with the first seven completed. His epithet “Father of Interstate River Compacts” is most appropriate.

Document: Colorado River Compact, 1922. Photo: Signing the South Platte River Compact, 1925.

Compact Dates and Facts

Colorado's Compacts

  • 1922 - Colorado River Compact, with Arizona, California, Nevada, New Mexico, Utah and Wyoming
  • 1922 - La Plata River Compact, with New Mexico
  • 1923 - South Platte River Compact, with Nebraska
  • 1938 - Rio Grande Compact, with New Mexico and Texas
  • 1942 - Republican River Compact, with Kansas and Nebraska
  • 1948 - Arkansas River Compact, with Kansas
  • 1948 - Upper Colorado River Compact, with New Mexico, Utah and Wyoming
  • 1963 - Costilla Creek Compact, with New Mexico
  • 1968 - Animas-La Plata Project Compact, with New Mexico

Facts about the Colorado River Compact

  • Divides Colorado River Basin into upper and lower basins at Lee Ferry, Arizona
  • Upper Basin states: Colorado, New Mexico, Utah and Wyoming
  • Lower Basin states: Arizona, California and Nevada
  • Apportions the right to exclusive beneficial consumptive use of 7.5 million acre-feet in perpetuity to the Upper Basin and the Lower Basin
  • Allows an additional 1 million acre-feet per year of increased beneficial consumptive use to the Lower Basin
  • Provides that the Upper Basin states will not cause the flow at Lee Ferry to be depleted below an aggregate of 75 million acre-feet for any period of 10 consecutive years

Defining Dates of the Colorado River Compact

  • 1920 - Compact clause of U.S. Constitution first proposed for interstate river appropriation
  • 1921 - Congress authorizes compact negotiations; Commissioners appointed from seven statesColorado River Compact Commission
  • 1922 - Negotiations throughout the year; Commission approves final draft November 24th
  • 1928 - Boulder Canyon Project Act enacted by Congress
  • 1929 - President Hoover signs Act, making Compact official
  • 1931 - Construction of Hoover Dam begins
  • 1936 - Hoover Dam completed
  • 1944 - Arizona ratifies Colorado River Compact

Photo: Colorado River Commission, 1922.

The Carpenter Collection

Delph Carpenter's papers documenting his work on Colorado's compacts are available through the Water Resources Archive. Letters and telegrams between commissioners, politicians, state engineers, and others show the exchange of ideas. Original maps, data, and reports Carpenter used to gather information which shaped his thinking exist in the collection as well. Meeting minutes and compact drafts trace the commission's discussions and debates.

In addition to Carpenter's professional papers, the collection contains personal and family items. Materials of his relatives, including Union Colony pioneers, a Civil War veteran, and his son Weld County Judge Donald A. Carpenter, exist in the collection, too.

The Carpenter Papers can inform many research topics, including:

  • Water rights and legislationCarpenter family
  • Water resources development
  • Interstate compacts
  • State sovereignty
  • Colorado state politics
  • The Union Colony of Colorado
  • Pioneer families
  • Cattle breeding
  • Women's roles
  • War veterans
  • and more!

The collection contains 150 boxes--including over 1,200 photographs--as well as more than 130 oversized items. A detailed guide to the collection is available. Also, over 800 digitized objects from the collection are available for browsing and searching.

Photo: Carpenter Family, 1925.

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