When did the Upper and Lower Basin of the Colorado River become a thing?

By Steve Harris | Guest Commentary, Rocky Mountain Voice

And other insights from the 1922 Colorado River Compact negotiations

Though I was not in attendance in 1922 (don’t laugh), the minutes of the negotiations are very thorough. At the first Commission meeting starting on January 30, 1922, the negotiations were centered on separating the Colorado River flow by the potential for irrigated lands in each state. Reclamation—only about 20 years old at the time—had made surveys of the potential irrigated lands in each state. The acreages are listed in the minutes of the first meeting.

Miss the first piece? Read: “Harris Water Time” and the Colorado River Compact’s century of lessons

Colorado River Commission delegates meet in Santa Fe, New Mexico, in 1922. Secretary of Commerce Herbert Hoover (center) chaired the negotiations that produced the four-page Colorado River Compact. Photo courtesy U.S. Bureau of Reclamation.

Of course, there was significant discussion on whether the acreage estimates were realistic based on the facilities needed to deliver water to the lands and whether there was water at each location to irrigate the lands. The January meetings ended without resolution on the irrigated acreage concept. A major issue was how each state’s acreage would be monitored and administered.

It wasn’t until the opening of the negotiations at Bishops Lodge outside Santa Fe, NM, that Delph Carpenter, Colorado’s representative to the negotiations, formally presented the concept of a 50/50 split of water between the Lower and Upper Basins at Lee Ferry. Importantly, the states in each basin would be responsible for allocation of the water in each basin separately from the compact, rather than the compact trying to allocate to each state.

Arizona wanted to have a specific allocation rather than putting off their allocation to the future, but that was a minority position in the end. The Upper and Lower Basin split simplified what the compact would do and centered the negotiations on what would be the volume split between the two basins.

Make no mistake—these guys liked to talk. They went around the Upper and Lower Basin concept at least twice during negotiations at Bishops Lodge. The Arizona representative was the most contrarian voice in the room. Finally, Hoover forced the group to vote on the 50/50 split, and they agreed.

What the 50/50 split in flow was for each basin is discussed in a future article.

They also talked when the compact should sunset—either on a certain date or after a number of years. Luckily, an end date was not included. Could you imagine negotiating something like that today? Just the modeling would wear everyone out.

The group even considered whether the compact could be terminated by just two states. The idea was fully discussed—and not included.

Arizona was especially concerned that the Upper Basin might store all the water for several years, then release the requirement in a short period. They proposed a minimum volume each year. Remember, these negotiations were decades prior to the construction of Lake Powell. That idea, too, was not included in the compact.

Map of the Colorado River Basin showing hydrologic boundaries and adjacent regions that receive Colorado River water. Source: Colorado River Board of California.

Amazingly, after all the discussions, the Commission was eventually able to boil down everything that was discussed in a four-page document that we now know as the Colorado River Compact and still use 100 years later.

In the next installment, Harris dives into how the Compact negotiators settled on the 7.5 MAF obligation at Lee Ferry—and the surprising math behind it. He unpacks flow data, diverging state positions, and the final agreement that still defines the Upper–Lower Basin relationship today.

Steve Harris is a distinguished water engineer based in Durango, Colorado, with a career spanning over 50 years that has significantly shaped water policy and resource management in the region. As president of Harris Water Engineering, Inc., he has led major projects such as the Dry Gulch Reservoir and played a guiding role in local and state water planning initiatives. Harris is widely respected for his advocacy of water conservation and xeriscaping, serving on the Animas Basin Roundtable and the Colorado Interbasin Compact Committee, and has worked closely with legislators to promote the sustainable use of water resources. His leadership and technical expertise have influenced landmark legislation, while his public outreach—such as the “Lawn Gone” campaign—underscores his commitment to balancing municipal and agricultural needs in Colorado’s water management.

Editor’s note: These articles were first published in 2022 for the Colorado River Compact’s 100-year anniversary. At a time when basin negotiations remain fraught and the river’s future uncertain, RMV is running the series to give readers both context and clarity through Harris’s seasoned perspective.

Opinions expressed in commentary pieces are those of the author and do not necessarily reflect the opinions of the management of the Rocky Mountain Voice, but even so we support the constitutional right of the author to express those opinions.