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[Source: Central Nebraska Public Power & Irrigation District and Wessels Living History Farm, 07.2016 | Keywords: Nebraska, Water]

Water – noun, wa·ter \ˈwȯ-tər, ˈwä-\

A clear liquid that has no color, taste or smell that falls from clouds as rain and forms streams, lakes and seas, and is used for drinking, washing, etc.

Water plays a huge role in our lives. We need it to survive. We drink it and cook with it. We bathe in it and use it to wash clothes. We boat and swim in it. We water our gardens, yards and crops.  

It can be found everywhere. From faucets, drinking fountains and irrigation systems, to lakes, rivers and rain, water is readily accessible across Iowa and Nebraska.   

That wasn’t always the case in Nebraska. Long ago, farmers in the south-central part of the state struggled to farm in the semi-arid environment. Today, thanks to a network of canals, dams, lakes and hydro-plants, the Central Nebraska Public Power & Irrigation District not only delivers farmers irrigation water, but generates electricity, provides recreational opportunities and supplies groundwater recharge benefits to south-central Nebraskans as well. 

While Iowa has an ample supply of water thanks to several rivers and streams, it has become very expensive to provide clean drinking water, due in large part to high nitrate levels. This issue came to a head two years ago when the Des Moines Water Works sued three Iowa counties over nitrates in the drinking water. While the potential trial has been delayed until 2017, Iowa farmers are taking several steps to help prevent future nitrate run-off. 

The name “Nebraska” comes from an Oto Indian word meaning “flat water,” referring to the Platte River. Flowing across the state of Nebraska, the Platte River plays a vital role in both powering and irrigating the state. 

One gem for Nebraska farmers is the Central Nebraska Public Power and Irrigation District (Central), created in 1933 to help the people of south-central Nebraska reach the state’s irrigation and electric power potential. A political subdivision of the State of Nebraska, Central is organized under the public power and irrigation district laws of Nebraska.

The overriding goal of Central is to “serve the agricultural-based community in south-central Nebraska by protecting and utilizing in a sustainable and ecologically balanced manner all of the natural resources available to us to provide reliable and reasonably priced surface water irrigation and ground water recharge while producing electric power and preserving and enhancing our quality of life and the natural environment in which we live. It is important that these activities be undertaken with the abiding conviction in, and understanding of, our overriding obligation to be good stewards of the region’s environment and its land and water resources.”

Today, the Central Nebraska Public Power and Irrigation District:

• Delivers irrigation water to more than 113,000 acres (1,300 accounts) on the south side of the Platte River between North Platte and Minden and provides supplemental water from Lake McConaughy (Central’s main storage reservoir) to irrigation projects serving more than 110,000 acres along the North Platte and Platte Rivers.

• Generates electricity for homes, farms and industry at four hydroplants, one at Kingsley Dam and three on Central’s Supply Canal.

• Provides recreational opportunities such as fishing, boating, swimming and camping at Lake McConaughy, Lake Ogallala, Johnson Lake and many other small lakes along the Supply Canal.

• Supplies groundwater recharge benefits to more than 310,000 acres irrigated by wells in and adjacent to Central’s service area.

• Offers habitat for many species of fish and wildlife.

It was a long and bumpy road getting the Central Nebraska Public Power and Irrigation District up and running. If it weren’t for the foresight and determination of some well-known Nebraskans, farming may have become obsolete in south-central Nebraska.

Over the Years

While irrigation in Nebraska dates back to the 1880s, its use was mostly confined to areas immediately adjacent to rivers and natural streams. Early irrigation methods and equipment were not very efficient, but they were better than the alternative – waiting for rain. 

Irrigation for consistent and abundant crop production rose to the forefront by 1894. However, the droughts of 1894-95 and 1899-1900 were not enough to convince the public, nor the government, of the need for an irrigation project.

As early as 1913, a group of community leaders in south central Nebraska came together and agreed that to make their area prosper, they needed to bring water from the Platte River to their farms. The main problem was that the water was at least 25 miles away and downhill.

C.W. McConaughy, a grain merchant and the mayor of Holdrege, brought up the idea of “supplemental irrigation.” He proposed that water from the Platte River be brought via canals to central Nebraska farmland during the spring and fall when river flows were at their highest. The water would be used to soak the soil, allowing crops to draw upon stored water during the growing season.

The Tri-County Supplemental Water Association was created later that year with McConaughy as president. McConaughy continued to speak on behalf of irrigation and was the main advocate of the irrigation movement during its early stages. “When I have seen for weeks the great volumes of water rolling down the Platte in the flood season to become a nuisance in the lower Mississippi, 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 of what Nebraska can be and ought to be if a combined effort were made by all of its citizens.”

In 1922, the Nebraska Supplemental Water Association was created and McConaughy was elected president. While the organization’s emphasis was still supplemental water as late as 1925, the production of power quickly became a factor in the development of an irrigation project.

Another influential figure in the early days of the District was George P. Kingsley, a banker and businessman. Kingsley worked from 1913 until his death in 1929 to make the dream of irrigation a reality, serving as vice president of both the Tri-County Supplemental Water Association and the Central Nebraska Supplemental Water Association.

The drought years of the 1930s forced individual farmers and lawmakers to face these fundamental questions: What kind of agriculture can be practiced in a semi-arid environment? How can we restore land that farming practices had damaged and avoid damaging the land in the future?

On July 24, 1933, the Nebraska Department of Roads and Irrigation approved a petition to organize the Central Nebraska Public Power & Irrigation District. J.E. Lawrence, a member of the state Public Works Advisory Board, recommended to the Public Works Administration that funds be allotted to aid Nebraska’s rural areas in their struggle.

In 1934 Lawrence wrote: “It is not a question of permitting land to lie fallow for a few years. The geologists in Nebraska and the agricultural experts connected with the University of Nebraska have assured the Nebraska advisory board that in a region where rainfall is no greater than it is in all of this area, 50 and possibly 100 years would elapse before the subsoil moisture could be rebuilt. That would mean the destruction of more than 5,000 farm homes and a still greater number in the 20 towns and cities included in the district. It would nullify the settled policy of the administration to encourage rural life and it would condemn a civilization which has established splendid schools, built churches and hospitals, and otherwise availed itself of all the modern conveniences and necessities to a futile, uneven struggle against the overwhelming odds of nature.”

In April 1934 engineers suggested that a dam and reservoir be built on the North Platte River near Keystone instead of two Plum Creek Reservoirs proposed in Tri-County’s plan. The proposed dam would store enough water to supply the Sutherland and Tri-County projects and some future irrigation projects. Long awaited approval of the Tri-County project came in August 1935.

Construction of the project began on March 13, 1936, with ground breaking on the Phelps County Canal, followed by simultaneous work on the Kingsley Dam, North Platte Diversion Dam, Supply Canal, three downstream hydroelectric plans and the irrigation canals and laterals. Most of the construction was finished during 1940 and the Supply Canal opened in November 1940. Power was first generated at the Jeffrey plant on January 5, 1941.

Construction of the Kingsley Dam was the largest public works project in Nebraska during the 1930s. One of the largest earthen dams in the world, the Kingsley Dam took five years to complete. Most of the soil surrounding the dam was very sandy, so workers had to drive a solid wall of interlocked sheet steel pilings across the riverbed and down between 30 and 160 feet. Over those steel pilings the workers pumped Loess soil – a fine grained clay and silt soil found more often in Iowa than Nebraska – to a finished height of 162 feet (the height of a 10-story building). Water was then drained out of the Loess and the soil hardened into a solid core. Over the core, local sand and gravel was pumped to form a pit. The entire dam contains 25 million cubic yards of earth and other material.

As Lake McConaughy filled up behind the dam, it created more than 100 miles of shoreline and beaches. At full storage of 1,948 acre-feet of water, “Big Mac” is 22 miles long, four miles wide, and 142 feet deep near the dam. When full, the lake covers 35,700 acres.

Irrigation delivery and related operations began in earnest in 1942 with deliveries to more than 44,000 acres. The project was officially completed in 1943 with a total cost of $43 million, paid by a $19 million PWA grant and a $24 million federal loan. The project provided jobs to more than 1,500 people.

When Central first began delivering water, agricultural practices were primitive. Horse- or mule-drawn implements were still used by many farmers and irrigation methods, such as canvas dams and lath boxes were crude. Making use of a temporary diversion dam located on the Platte River about 10 miles southeast of Lexington, Central first delivered water to the newly dug canals in the irrigated area during the spring of 1938. Approximately 3,300 acres received up to nine inches of water per acre that summer, resulting in immediate and significant increases in crop yields.

Over the next 35 years, the number of irrigated acres grew to more than 123,000 (the number of irrigated acres has remained stable at about 112,000 acres since 1984) and the canal system operated as designed with only minor changes or improvements, including the replacement of wooden turnouts with concrete structures, and the construction of the E67 Canal in the mid-1950s.

Advances in technology and a better understanding of hydrogeology brought improvements over the years, starting with planning and design for the E65 Rehabilitation Project in 1969. Small project loans from the U.S. Bureau of Reclamation allowed Central to rehabilitate and modernize its two main irrigation systems: the E65 Canal, which serves almost 43,000 acres in the Bertrand-Loomis area; and the Phelps Canal, which serves almost 60,000 acres from northwest of Holdrege to north of Minden.

The E65 project involved enlarging most of the E65 Main Canal, new control structures, the addition of Elwood Reservoir and installation of supervisory control equipment on the principal operating structures.

Elwood Reservoir, located just south of Johnson Lake, is filled during the non-irrigation season by diverting water from the Supply Canal into the E65 Canal. Each year, approximately 24,715 acre-feet are pumped at the Carl T. Curtis Pump Station into the reservoir, which has a capacity of more than 40,000 acre-feet. The water is then allowed to flow back out of the reservoir during the irrigation season for delivery to irrigation customers. The releases augment the E56 Canal’s diversion capacity of approximately 365 cubic feet per second.

The project also improved service to E65 customers by increasing deliveries from 1 acre-foot per acre per season to 1-1/2 acre-feet per acre per season and switched deliveries from three-week rotations to two-week rotations.

The Phelps Canal is Central’s largest irrigation canal with a capacity of 1,300 cubic feet per second. More than half of the Phelps system’s 250 miles of canals and laterals were replaced, rehabilitated or improved by 1986 and additional improvements have been made on an annual basis since that time.

The E67 Canal, which serves more than 5,000 acres southeast of Johnson Lake, was added to the system in 1954 at the request of area farmers who experienced difficulty in procuring adequate supplies of groundwater. In 2001, Central began another ambitious improvement project on the E67 Canal. Completed in time for the 2003 irrigation season, the project replaced most of the canal system’s open laterals with 18 miles of buried pipeline and 2.8 miles of membrane lined canal.

The project provided a two-week delivery rotation for irrigation customers, rather than the three-week rotation that had been in place since the canal went into service. Transportation losses (seepage and evaporation) were largely eliminated, resulting in an annual reduction in diversions to the canal system by 45 to 50 percent.

Central continues annual maintenance and improvement activities on its canal systems. Several small and/or inefficient canals have been abandoned or replaced with pipelines and the membrane lining has been added in areas where seepage losses were unacceptably high.

Central also provides irrigation water to more than 6,500 acres served directly from the Supply Canal as it passes through Lincoln and Dawson counties to the headgates of the three irrigation canals in northeast Gosper County.

Conjunctive Use

An important part of the rehabilitation projects was the attention given to designing, incorporating and improving the ìconjunctive useî aspect of Centralís system. Conjunctive use is the recognition of the hydrologic relationship between surface water irrigation and groundwater resources and the effective, efficient use and management of both resources to produce sustainable social, economic and environmental benefits.

During the planning stages for the E65 rehabilitation project, computer groundwater modeling studies of the system resulted in a design that provides recharge where groundwater development (irrigation wells) is heavy and a lined system, or pipelines, where irrigation comes mainly from the surface water system. The result has been a generally stable water table beneath and adjacent to Central’s service area.

Central’s efforts also marked the first time in Nebraska that an irrigation system was designed to address the water supply and the needs of both surface and groundwater irrigators. Central monitors a system of 137 observation wells throughout the service area, enabling the District to compile the necessary data for continued evaluation of groundwater levels.

Data from the U.S. Geological Survey and the Conservation and Survey Division of the University of Nebraska-Lincoln show that the water table beneath Central’s service area has risen since the system went into operation in 1941 by 10 feet to more than 50 feet. Similar data from counties just outside Central’s service area show just the opposite – declines in the groundwater table of five to more than 30 feet over the last 60 years.

Water Rights

Central has several types of state water rights. Irrigation water rights have been obtained for the land served by Centralís distribution system. These water rights remain with the land regardless of its ownership as long as water is applied to the land. Irrigation water rights for each parcel fall into two categories: natural flow and storage use rights.

Natural flow is diverted from the base flow of the river and these types of water rights are administered by the Nebraska Department of Natural Resources on a “first-in-time, first-in-right” principle. As the natural flow of the river diminishes, junior water rights are shut down so more senior, or older, water rights can continue to receive water. Central’s earliest water rights were obtained in 1934, but are still junior to most other Platte River water rights, many of which date back to the 19th century.

The majority of Central’s diversions for irrigation is storage water released from Lake McConaughy. Central has a water right to store 2 million acre-feet annually behind the Kingsley Dam.

Several irrigation projects that depend primarily on natural flow water rights contract with Central or other irrigation projects for supplemental water; that is, storage water that can be delivered when natural flow is unavailable or available in insufficient quantities.

Another type of water Central holds is a permit to divert water for the production of hydroelectric generation at its four hydroelectric plants.

The management of water resources is an important part of Central’s operations. To manage the system properly, it is imperative that accurate measurements are taken and that thorough records are compiled. Such practices enable Central to evaluate and adjust its operations accordingly.

Each customer’s turnout is fitted with a water meter or is measured by an Irrigation Service Specialist (ISS). Records of deliveries are kept down to the tenth of an inch.

Central has been active in water conservation efforts for many years and has gone to great lengths to improve the efficiency of its delivery system. Practices include conversion of turnouts to pipe outlets fitted with flow meters; encouraging the use of soil moisture blocks and soil probes to measure soil moisture; digging reuse pits for landowners throughout the irrigated area; improvements in the supervisory control system to increase the timeliness of deliveries; creating the position of conservation director to work directly with irrigation customers on on-farm systems; cooperation with federal and state natural resources agencies; and adoption of conservation policies that encourage and reward irrigation customers for adopting conservation measures or practices.

Such efforts include the pivot incentive policy that has prompted a dramatic increase in the number of pivots served by Central’s irrigation system. In 2008, more than 250 pivots, covering more than one-third of the contracted acres, were operating on Central’s system. Central also provides cost-sharing for other conservation measures.

Gated pipe has become the most common delivery method and siphon tubes, a common sight in furrow-irrigated fields for many years, have all but disappeared. Central also encouraged the use of surge valves, which increase the efficiency of gated pipe irrigation, and many irrigation customers have installed the devices.

As a result of Central’s efforts to efficiently manage and conserve its available water resources, the Irrigation Division continues to operate one of the most efficient irrigation projects in the western United States.

Source: Central Nebraska Public Power & Irrigation
District and Wessels Living History Farm