May Inflows to Lake McConaughy Ranked 5th Highest

May Inflows to Lake McConaughy Ranked 5th Highest

By now, everyone knows this spring was, well, on the wet side. While rainfall during May in Central’s irrigated area was only slightly above average (Central’s gauge in Holdrege collected about 2.3 inches, about 104 percent of normal), that followed an April during which more than nine inches of rain fell across most of the area and even higher localized totals were reported from some rain gauge sites.

But what happened in south-central Nebraska pales in comparison to what was (and is) occurring in the western part of the Platte River Basin.

The 2015-16 water year (Oct. 1 to Sept. 30) started off in a fairly innocuous manner. Inflows to Lake McConaughy in October, November and December were very close to normal. The new year started with more of the same. The first four months brought inflows that ranged between 75,000 acre-feet and 79,000 acre-feet, again only slightly above historical median, or normal, inflows.

The pattern changed in May. Inflows to Lake McConaughy during April had lagged below normal until the last day of the month when they finally climbed to 1,876 cubic feet per second (cfs), about 350 cfs higher than normal. Over the next 31 days, the faucet was open all the way. The daily average inflow during that period was 6,394 cfs, far exceeding the normal daily average of 1,729 cfs. At May’s end, more than 393,000 acre-feet had flowed into Lake McConaughy, almost six times the amount (69,252 a-f) that normally arrives at the reservoir during the month, and certainly more than was projected. In fact, inflows during May were the fifth highest on record. (See table.)

Water YearInflow (acre-feet)
1.      1970-71451,524
2.      1983-84425,461
3.      2010-11420,804
4.      1972-73411,080
5.      2015-16393,132*
6.      1941-42340,031
7.      1982-83313,413
8.      1998-99235,133
9.      1979-80228,063
10.   1996-97197,200

(*Provisional)

May inflows peaked at 8,564 cfs on the last day of the month, then clicked up a notch to 8,716 cfs on the first day of June, which is the highest daily inflow since June 20, 2011 when the river gauge at Lewellen hit 9,000 cfs. So far this month, inflows have been steadily declining (inflows were at 6,750 cfs on the day this was written, still more than three times the normal rate, but declining nevertheless), which was actually welcome news as Lake McConaughy was nearing its maximum storage elevation.

As March began, snowpack in the upper and lower North Platte River basins and the South Platte was near normal. Inflows to Lake McConaughy, as stated above were at or slightly below normal. Reservoir storage in the U.S. Bureau of Reclamation’s North Platte River reservoirs was also near normal for the time of year.

The picture looked pretty much the same when April arrived, nothing to get too excited about. Snowpack accumulation in the upper North Platte Basin was at 101 percent of normal; while the lower basin (which typically provides less runoff than the upper basin) was at 121 percent. Experts were expecting “good” runoff, but not quite the volume of water that would show up in the Platte Basin during May.

Heavy snow fell in the Rocky Mountains; at lower elevations and rainfall came in quantities that were well above normal. Conditions rapidly changed; what was setting up to be a “good” year for inflows suddenly turned to exceptional.

Water managers with the Bureau of Reclamation started releases from Glendo Reservoir in early May to make room for expected high inflows, but despite the early releases, storage behind Glendo Dam soon reached the flood pool level. Glendo is the only reservoir in the North Platte Basin with a designated flood pool, which can hold about 300,000 acre-feet. As June began, there was still about 200,000 a-f of flood pool space remaining and water being held in the reservoir helped reduce the high flows crossing into Nebraska.

In summary, late spring rains – which are typical, but not in the quantity that ended up falling — and the late beginning to the spring snowmelt in the mountains because of cooler than normal temperatures combined to produce the volume of water now in the rivers.

To complicate matters, snowmelt is also just beginning in the South Platte Basin. Flows in the South Platte recently had been running well above normal before falling off to near normal. However, a lot of snow remains to melt from the higher elevations and there is little room for storage in Colorado’s off-stream reservoirs.

While flows in the South Platte are currently well below flood stage, that might change, depending upon how fast the snow melts and how much precipitation falls in the valley over the next few weeks.

With temperatures on the rise, demand for irrigation water will soon increase up and down the Platte River Valley, which will take some of the water out of the river. But it’s probably safe to assume that there will be higher than normal flows in the Platte Basin for much of the summer.

From the Archives: “This Day in History”

From the Archives:  “This Day in History”

Kingsley Dam was completed in 1941, so as we approach in 2016 the 75th anniversary of the dam and the beginning of project operations, we will be posting a list of historical highlights from the District’s past, sort of a “This Day in History” compilation. The entries will added according to when they occurred over the calendar year.

APRIL

April 11, 1941 — George Johnson, Central’s chief engineer and general manager, predicted that the Platte River would have a steady year-round flow within three years.  The construction of Kingsley Dam and Lake McConaughy, which would store flows in the North Platte River for irrigation deliveries and hydroelectric generation, would eliminate the “no-flow” periods — particularly in the central Platte stretch — that were common before the dam was built.  (Subsequent history would prove Johnson largely correct.)  The canal system — including the Supply Canal and the irrigation canals — would eventually contribute underground return flows helped stabilize base flows in the river.

NOVEMBER

Nov. 1, 1933 – The Central Nebraska Public Power and Irrigation District was officially organized after State Engineer Roy Cochran gave conditional approval to a reorganization of the District. The District’s creation had initially been approved by the Nebraska Department of Roads and Irrigation on July 24, 1933 as the Central Nebraska Public Power and Irrigation District, although several hurdles remained to be cleared. Having made progress toward gaining approval and funding for the hydro-irrigation project, the new organization – officially called THE Central Nebraska Public Power and Irrigation District – was created by the state engineer’s approval on Nov. 1.

Nov. 7, 1940 – Central’s board of directors signed a farm management contract with the University of Nebraska, placing what was called the Tri-County Farm Management Farm (which was used to demonstrate best management practices to farmers still learning about irrigated farming) under the supervision of the University’s Board of Regents.

November, 1940 — The two dredges pumping fill for Kingsley Dam — one upstream and one below the dam — completed the project that built (at the time, behind Ft. Peck Dam on the Missouri River in Montana) the second largest hydraulic-fill dam in the world.  Approximately 25.5 million cubic yards of sand and gravel were pumped during the process.  Following completion of dredging activities, workers plugged the huge tube that carries water from the North Platte River beneath the dam (now connected to the Morning Glory Spillway) and water began passing through the Control Tower.  The process of filling the reservoir was expected to begin in the spring of 1941.

November, 1965 – Central crews, under the supervision of Kingsley Dam Division Manager Bernard Donelan, finished what was originally planned to be a three-year project of placing 800-lbs. tetrahedrons on the face of Kingsley Dam. The 16,360 “tets” were placed in a matter of months because the growing season proved to be wet, resulting in low demand for water from Lake McConaughy and freeing up members of the crew to work on the dam instead of their normal irrigation-related duties. A private contractor poured the concrete jackstones at a site near the dam and subsequently manufactured several thousand more to stockpile near the dam. The jackstones were designed to protect the dam’s face by breaking wave action against the dam.

November 2004 – Maps prepared from data accumulated by the UNL Conservation and Survey Division revealed, “Significant and persistent declines in some areas of the state (that) have only become more obvious in the last few years due mainly to current drought conditions and resulting increases in groundwater pumping.” The UNL Water Center noted a spike in well drilling that occurred after passage in the spring of LB962 (a law intended to prevent conflicts between groundwater and surface water users) that spurred a rush to drill additional wells before a moratorium on new wells in some areas went into effect. According to UNL hydrogeologist Jim Goeke, “The increase in pumping and diminished recharge to the aquifer due to drought disrupts groundwater flow to streams, delaying or diminishing the flow of surface water in many basins.”

November 2009 – After 25 years and generation of almost 2 million megawatt-hours of electricity, the Kingsley Hydroplant finally required significant repairs and maintenance. Central crews began complete disassembly of the turbine-generator unit prior to repair of bushings in the turbine hub, cavitation repair on the turbine blades, refurbishment of wicket gates and oil seal improvements. The $4 million project was completed by March 2010.

OCTOBER

Oct. 10, 1955 – Central’s board of directors and management announced plans to build a 100-megwatt power plant to be fueled by natural gas. The plant, which went on-line in 1958, was constructed adjacent to the Supply Canal southeast of Lexington, was named the Canaday Steam Plant after Ralph O. Canaday, who served as the District’s legal counsel during the formative years of efforts to bring an irrigation project to south-central Nebraska and later served as Central’s chief legal counsel and general manager.

Oct. 17, 1956 – During a drought in the mid-1950s, Lake McConaughy dropped to its lowest elevation on record since the reservoir’s initial fill. The lake’s elevation on this date was 3,198.2, with a volume of 348,900 acre-feet. At the time, the reservoir’s maximum capacity exceeded 1.9 million acre-feet, so the amount of water behind Kingsley Dam represented only 18.4 percent of capacity. The low-water mark would stand until September 2004 when the lake fell to an elevation of 3,197.6 feet during another extended drought. At that time, Lake McConaughy contained 341,400 acre-feet, or 19.6 percent of its current maximum capacity of 1,743,000 acre-feet. The reservoir’s maximum capacity was lowered in the early 1970s after a 1972 windstorm damaged the protective face of the dam.

Oct. 19, 1964 – A project began to replace an original – and somewhat iconic – structure along Central’s Supply Canal. The “High Bridge,” located on a county road over the canal south of Cozad was 219 feet long and stood 74 feet above the canal’s water surface was originally constructed in 1938 and was the highest bridge in the District. Age and wear-and-tear took its toll on the wooden bridge and it was replaced by a new bridge that stands 33 feet above the canal.

bridge-construction

The original “high bridge” under construction over the Supply Canal south of Cozad.

high_bridge_replacement

The replacement bridge under construction in 1964.

Oct. 26, 1990 – More than 800 people attended a “scoping hearing” at the Ogallala City Auditorium conducted by the Federal Energy Regulatory Commission in connection with the relicensing of Central’s (and the Nebraska Public Power District’s) hydroelectric project. More than 35 people testified during the five-hour meeting, almost all in favor of issuance of a new license with conditions that would not hinder provision of the many benefits from the project.

Oct. 27, 1997 – Central construction crews began an earthwork project to raise the head above a siphon on the E-65 Canal and to install more than 2,000 feet of synthetic membrane. The earthwork would provide six more feet of elevation above the siphon to increase the volume of water passing through the mile-long pipe. The membrane lining significantly reduces conveyance losses and prevents bank erosion along the E-65 Canal between the head gate near the Johnson Lake inlet and the siphon.

October 2001 – Central started a major rehabilitation project on its three Supply Canal hydropower plants. The project involved replacing the original turbines, rewinding all five generators and installing a new transformer in the J-2 hydroplant switchyard.

 

From the Archives: Dam Named in Honor of George P. Kingsley

From the Archives: Dam Named in Honor of George P. Kingsley

(Reproduced verbatim from the Hastings Daily Tribune, July 7, 1937)

Major Tri-County Unit Will Memorialize George P. Kingsley, Pioneer Project Leader

The Trico board of directors late yesterday took steps to adopt the name Kingsley Dam for the major unit of the Tri-County power and irrigation district.

George P. Kingsley

George P. Kingsley

The name thus chosen memorializes the late George P. Kingsley, who throughout the last 20 years of his life contributed more in means, time and energy to this particular public works movement than any other person.

Heretofore the unit has been informally called the Keystone dam, because the location is close to the town of Keystone. The latter, however, is below the dam and bears no relation to the unit except proximity, and that is a matter of some four or five miles.

George P. Kingsley was the father of Dr. D.W. Kingsley who has been president of the district organization since it was organized under the law known as Senate File No. 310. He piloted the movement through its most discouraging stages, never faltering in the face of almost insurmountable obstacles, and donating constantly to the funds which were required for its promotion.

Countless trips to Washington, long stays at Washington and at the state capitol, attendance at meetings without number in Nebraska, and unceasing labor with scientists, technical persons, industrial leaders and others who had a part in shaping the project and bringing it to the favorable attention of the public, were all a part of Kingsley’s contribution.

The action of the Trico board is in full compliance with the PWA rule forbidding the naming of public works units after living persons. Though an exception was made in the case of the Norris, dam, the rule otherwise has been invariably observed with reference to all structural units of major importance.

The death of George Kingsley preceded the approval of Tri-County by the president and the public works administration.

Though he did not live to see the full realization of the dream to which he and a few others had dedicated the later years of their lives, he had definitely concluded that on the basis of merit and the opportunity provided through the government’s enlarged participation in public works that sooner or later constructions and operation of the project was inevitable.

Authority was given by the board of a request to PWA that the official name be recorded in the files, maps, charts and other records at Washington.

The Kingsley Dam will create a lake that will extend back the river for a distance of 23 miles. It will be one of the largest inland bodies of water in America, next to the Great Lakes, and the dam itself in size will rank second in the world to Fort Peck in the earth fill classification.

From the Archives: Dam Worker Lives to Tell Story of Trip through Pipeline

From the Archives: Dam Worker Lives to Tell Story of Trip through Pipeline

Reprinted from the Hastings Daily Tribune, January 1940

Human Interest – Dam Worker Lives to Tell of Being Swept Through Trico Dam Drain Pipe

Human interest stories are sprinkled through the many years of Tri-County promotion.

Human interest stories have also cropped up at frequent intervals during the huge construction program. There has been humor and tragedy.

Best story of recent months coming from the far-flung construction front could have been tragic. It wasn’t, and its very hair-raising details would make it subject matter for the writers of those stories which keep you holding your breath but always turn out all right in the end.

Here are the details:

Robert McCoy, 26, on December 6, 1939, was employed by the contractors building the huge earth fill at Kingsley Dam. He and a companion were on a boat tending the openings from which water drains from what is known as the “core pool,” the body of water visible in the central picture on the front of this section of the Tapeline (see photo below).

The core pool is formed by the clay and water pumped from the hills south of the dam. The water brings the clay, the clay settles to form the impervious core of the dam. The core is built up by the dredging of loess soil from the hard ground south of the river, while the bulk of the dam is given form by the piling up of sand dredged from the river bed.

Look at the panoramic view of the incompleted dam. You will see a small speck near the center of the view, to the left of the long line which is the pipe carrying clay from the hillside to the core pool. That speck is the opening of a 24-inch pipe, one of several. (The “speck” is not visible in the accompanying photo, which is not the same one published in the Hastings Daily Tribune.) This pipe and its companions serve to drain water from the core pool after the silt has settled to its permanent place in the huge fill.

Getting back to McCoy. He fell off his boat and was caught in the rush of water into the pipe. He went in feet first, dropped about 300 feet, made the right angle turn at an elbow and was bumped along for some 500 feet through the 24-inch corrugated pipe to the outlet at the upstream toe of the dam.

His companion was helpless. When McCoy disappeared, the only thought of the man left on the boat was how to get the body out of the pipe. It would be lodged in the elbow, he assumed.

This second man hurried to a nearby shack to report to fellow workers. He had barely explained the situation when up from the toe of the dam came McCoy. He entered the shack and collapsed.

Considerable muddy water was pumped from his lungs. He was ill for a few days and his face was mighty sore from being knocked against the corrugated pipe. Otherwise, there is nothing else to the story, as it is told by the Tri-County workmen who have looked over the scene and are still wondering how McCoy lived to tell about it.

The story has served to clarify for more than one person – this writer for example – the significance of the core pool in the dam project.

Kingsley Dam construction 497

Removal of Lost Creek Flume

Removal of Lost Creek Flume
image (6)

Central employees begin removal of flume structure following the end of irrigation deliveries for 2014.

Work began this week on removal of the Lost Creek Flume west of Axtell. The flume, approximately 1,300 feet in length, is original to the project and has required numerous repairs. Over the years, it has deteriorated to a point that repair is no longer feasible, and Central’s board of directors voted in May to replace it with 2,700 feet of 42 inch pipeline, which will be used to continue to provide water to 1,785 acres downstream of the flume.

DSCF3389

A view from on top of the flume. Water is seen flowing through to provide irrigation water during summer 2014.

IMG_3535

The check gate shown here is used to control flow of water through the flume.

DSCF3390 IMG_3585

Kingsley Dam Dedication – July 22, 1941

Kingsley Dam Dedication – July 22, 1941

On this day in 1941, Kingsley Dam was officially dedicated. Water storage in Lake McConaughy began to fill and irrigation water was delivered that same year. The project as a whole was officially completed in 1943.

Chief engineer George E Johnson at dedication 339

Chief Engineer George E. Johnson is shown above speaking at the dedication ceremony.

 

Dedication ceremony 337

A large crowd gathered to attend the official dedication of Kingsley Dam.

 

Cutting line to drop capsule 7-22-41 338

Two young girls are shown here cutting a string to drop a capsule into the dam at the ceremony.

 

For more information on the history of the Central Nebraska Public Power and Irrigation District, visit our History page here.


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