In the early 1900s in the arid West, C. W. McConaughy recognized the discontinuity between high river flows in the spring and low flows in the middle of summer, when farmers needed water most.

“When I have stood and seen for weeks great volumes of water rolling down the Platte in the flood season to become a nuisance in the lower Mississippi and when I have seen the semi-arid lands in our counties suffering and thirsting for water during the crop-growing season, my heart has been set on fire with a vision,” McConaughy wrote. “I have a vision of what Nebraska can be and ought to be if a combined effort were made by all of its citizens.”

McConaughy, a grain merchant and mayor of Holdrege, Nebraska, developed the idea of supplemental irrigation.

“Apparently nature has intended it (flood water) for supplementing rainfall in this territory. All man must do is to lead it from the streams out upon the great divides and let it soak into the subsoil where it is ready for plant use,” McConaughy wrote.

On November 26, 1913, McConaughy created the Tri-County Supplemental Water Association with plans to build two storage reservoirs by Plum Creek in Gosper County. His vice president, George Kingsley, was a Minden banker and businessman. Kingsley had heard McConaughy speak of the agricultural gains from supplemental irrigation and quickly became involved. With George Kingsley as Vice President, McConaughy and Kingsley pushed through much opposition to make the dreams of irrigation a reality.

McConaughy encountered many obstacles along the way to bring supplemental irrigation to Nebraska. After receiving money for a survey to determine the feasibility of his plan, it was shut down due to a misconception by the surveyors. The surveyors treated the plan as a regular irrigation project, not supplemental. They determined that there would not be enough water in the Platte River to irrigate crops.

The dry summer of 1926 brought a new hope to the Tri-Country proposal. More and more famers became convinced of the need for irrigation water. But attempts to secure favorable legislation were met with strong opposition. The Lower Platte (Sutherland) irrigation project was trying to secure a federal loan for their project. The Sutherland project was now competing with the Tri-County for funds and Platte River water rights. While the Sutherland project received approval, the Tri-County project was also able to establish water rights. An agreement was made between both parties but Tri-County still did not have approval to go forward with the project.

In 1934, engineers with the Public Works Administration (PWA) visited Nebraska and suggested that just one dam and reservoir be built on the North Platte River near Keystone, instead of two. They determine that this would supply enough water for both the Sutherland and Tri-County project. However, the PWA was not able to supply the funds for this project.

In 1935, the project to create one large reservoir was approved. McConaughy was disappointed, however, since he still wished to build two smaller reservoirs near Plum Creek. He was so upset that he resigned from Tri-County. Ironically, the reservoir is still named after him.

Construction of the Tri-Country project began in March of 1936. Kingsley Dam was finished in 1940 and closed in 1941, allowing water storage in Lake McConaughy to begin. The dam was dedicated on July 22, 1941 and the first irrigation water from Lake McConaughy was delivered that same year.

In the late 1970s, engineers began to consider putting in a hydroelectric plant on the other side of Kingsley Dam, between Lake McConaughy and Lake Ogallala, because of rising fossil fuel costs. In 1981 construction began and the project was dedicated on October 17, 1984.

Prior to the construction of the hydroplant, no one knew about the low dissolved oxygen levels in Lake Ogallala. Low oxygen levels can stress aquatic life and cause lake stratification. Before the creation of the plant, water was pulled through an open port at a high velocity, drawing oxygen in. Once the hydroplant was completed, water deep in Lake McConaughy, with low oxygen levels, was released to Lake Ogallala. In order to remedy this situation, engineers designed a structure to aerate the water with oxygen by spraying it out into the lake, known today as the “Rooster Tail.”

In 1998, after years of negotiations, the project successfully renewed its federal license, with the requirement to include an environmental account, a quantity of water set aside to supplement flows for wildlife. The Federal Energy Regulation Commission required the environmental account to address threatened and endangered species. Ten percent of water flowing into Lake McConaughy during non-irrigation season can be used for anything that enhances the environment for endangered species. Water has been released in the summer to create sandbar islands for animals like the piping plover near Gibbon. In the later winter and early spring, water is released to provide sandhill cranes adequate water to be protected while roosting. High flows have also been released to wash out vegetation in channels down by Kearney.

Today Lake McConaughy provides supplemental water to irrigation projects serving more than 110,000 acres along the North Platte and main stem Platte River.

Recently water scarcity has been a major issue for Lake McConaughy and Kingsley Dam. Under current inflow conditions, sustaining water in Lake McConaughy may not be possible. On September 14, 2004, an all time low reservoir level was recorded. The lack of water is due to a loss of upstream inflows, which are fed by return flows more than direct snowmelt. In order to increase the capacity in Lake McConaughy, inflows must increase or outflows must decrease, both of which are difficult due to the ever-growing water demands in the region.