In addition to the GI Bill and his other accomplishments, Mac is  remembered for his efforts to create a sustainable water system for  Arizona.

During his second term as US Senator, Mac worked diligently in trying to secure Arizona’s Colorado River water rights. Though the Colorado River Compact  had been created in 1922 to allocate the water from the river, Arizona  had refused to sign it. With new legislation in motion to allocate water  to Mexico, Arizona signed the compact in 1944.

Mac worked closely with fellow Arizona Senator Carl Hayden to develop bills to create the Central Arizona Project (CAP)  and deliver Colorado River water to central Arizona. In 1947, he  introduced Senate Bill 1175, but it failed to obtain the necessary  hearings for passage. In 1949, he introduced Senate Bill 75, which  passed the Senate but was defeated in the House. 

California was in competition with Arizona for the Colorado River waters and had a larger number of Representatives in the House due to its larger population. In 1951, Mac reintroduced Senate Bill 75. It was again defeated in the House.

Arizona v. California

During his tenure as governor, Mac, in an unprecedented move, argued before the United States Supreme Court in what would become the  longest Supreme Court case in American history, Arizona v. California.

Mac worked with Congressman Stewart Udall to evaluate the potential  of developing the Central Arizona Project, since no headway was being  made in Congress. While this failed, the effort demonstrated Mac’s  efforts to look at other options to accomplish an important, and  seemingly impossible, task.

Mac then did something that was at the time unprecedented. He  personally traveled to Washington D.C. to present before the Supreme  Court in Arizona’s case against California over the waters of the  Colorado River.

His arguments would ultimately result in the Colorado Basin Project  Act of 1968, which ensures the state water to this day through the  Central Arizona Project.

Excerpt from transcript from Eight/KAET Arizona Stories*******

“McFarland committed his presentation before the Supreme Court to  memory. And one of the things he did is he’s up all night writing notes  and throwing them in the garbage. Now, archivists would just blanch at  that, but he threw his notes away. But he went in before the Supreme  Court, argued beautifully; Arizona won its motion.”

Dr. Jack L. August, Jr., Arizona Capitol Museum