1983-1985 Last gasp for "Big Irrigation"
In the aftermath of Oahe's demise, South Dakotans who believed the federal government owed their state a large irrigation project as compensation for lands lost beneath Missouri River reservoirs promoted the Cendak and Garrison Extension irrigation project concepts as reasonable and plausible.
Skeptics of this approach –that building large irrigation projects in eastern South Dakota woudl serve as compensation for lands permanently flooded by mainstem reservoirs on the Missouri- pointed to historical analysis indicating that large-scale, federally funded irrigation projects had never succeeded in areas where farming was already successful. That was the situation in eastern South Dakota, where Oahe would have served an existing farming region. During the protracted settlement negotiations for the Oahe project John Sieh calmed United Family Farmer members worried about possible construction of Cendak and Garrison Extension projects by explaining that each was poorly conceived and would never be built. Sieh had been right. Lacking scientific and economic justifications Cendak was eventually mothballed. The same fate came to Garrison Extension, a quarter-billion dollar water delivery and irrigation project using polluted return flows from the yet-unbuilt Garrision project, a North Dakota irrigation project. Garrison Extension would have necessitated channelization of the James River, and progressive lawmakers in South Dakota and Washington rigidly opposed that idea.
The notion of developing a major irrigation project in eastern South Dakota faded as big project supporters began to understand the long-term liabilities and political challenges of such pursuits. The Bureau of Reclamation had, over the course of 80 years, developed dozens of large irrigation projects across the West, but the agency had simply run out of places to build such projects. It was not illogical that the agency tried to expand its reclamation domain into eastern South Dakota, but the factors that blocked this from happening coincided with the rising influence of ecological issues and the environmental movement, and an emerging and widespread suspicion about the competence and motivations of federal development agencies, some of which can be traced to Watergate and governmental conduct during the Vietnam War. As it turned out, economic and environmental conditions associated with both the Oahe and Cendak irrigation project blueprints were likely better served by not building either project.