Flow attenuation plan designed to protect nesting habitat

Flow attenuation plan designed to protect nesting habitat

With the summer months approaching, Central would like to provide a reminder about operations at Johnson Lake, specifically the requirement to adhere to a plan to protect nesting habitat for two threatened/endangered avian species along the Platte River.

The Flow Attenuation Plan, or “Spike-Flow Plan” (Plan), was developed several years ago with input from the U.S. Fish and Wildlife Service and the Nebraska Game and Parks Commission. It is intended to help attenuate (reduce) flows on the Platte River below the Overton measuring gauge during the least tern and piping plover nesting seasons.

The Plan is designed to keep Platte River levels at lower levels, thus reducing the chances of flooding nests located on sandbars. The Plan requires Central to use Elwood Reservoir and up to 2,500 acre-feet of space in Johnson Lake and immediately above the J-2 Hydroplant to help attenuate river flows. It enables Central to respond to large rain events during the irrigation season and reduce the release of rejected irrigation water to the river.

Water is released from Lake McConaughy during the irrigation season to serve more than 100,000 irrigated acres primarily in Gosper, Phelps and Kearney counties. Water from Lake McConaughy takes four to five days to travel the 125 miles to the headworks of the irrigation systems. The Supply Canal also collects rainfall runoff in its watershed, so its flow may vary beyond what is diverted at the North Platte Diversion Dam.

On occasion, large rainfall events occur in the Platte River basin and Central’s irrigated area. Heavy rainfall increases river flows and often prompts many irrigators to stop taking water. Since these rain events sometimes occur with little notice, and water has already been released to meet irrigation demands, a large quantity of water may be moving through Central’s system when it isn’t needed for irrigation (remember the travel time between Lake McConaughy and the irrigated area). This excess water must either be regulated in Central’s system or returned to the river. Returning the water to the river means losing precious storage water for irrigation purposes.

To have 2,500 acre-feet of space in Johnson Lake to hold rain and rejected irrigation water, the lake must be kept at the lower end of normal levels. From June 1 to Aug. 15 each year, Johnson Lake will be operated near the low end of the normal operation range (see Johnson Lake Elevation Graph) so that space is available if attenuation is required. When attenuating flows, Johnson Lake levels will increase until the water is released to the river at low flows or diverted to the irrigation canals. The water levels will then decline to the lower end of the operating range in preparation for another attenuation event.

Construction Underway on Pedestrian Bridge over Hike/Bike Trail

Construction Underway on Pedestrian Bridge over Hike/Bike Trail

A Central crew began construction of the pedestrian bridge over the Johnson Lake outlet canal in early October. The last pilings were driven on Oct. 12, setting the stage for construction of the supporting infrastructure and deck.

When completed, the bridge adjacent to the existing road bridge will afford safe crossing of the outlet by users of the lake’s hike/bike trail. The 10-feet-wide bridge will be constructed of wood and rest on steel pilings.

Central used a 30-ton crane equipped with a pile-driver that was positioned on the existing road bridge. Using the existing bridge as a “base” for construction will save on the cost of the bridge. The bridge is scheduled to be completed before Thanksgiving.

Central personnel finish driving the last steel piling for the pedestrian bridge.

Central personnel finish driving the last steel piling for the pedestrian bridge.

National Dam Safety Awareness Day is May 31

National Dam Safety Awareness Day is May 31

National Dam Safety Awareness Day occurs on May 31 of each year to commemorate the failure of the South Fork Dam in Johnstown, Pennsylvania in 1889. The dam failure resulted in the loss of more than 2,200 lives and is the worst dam failure in terms of fatalities in the history of the United States.

Photo courtesy of National Park Service

Aftermath of Johnstown Flood. Photo courtesy of National Park Service

National Dam Safety Awareness Day was created to encourage and promote individual and community responsibility for dam safety, as well as to provide information on what steps can be taken to prevent future catastrophic dam failures. A secondary goal is to promote the benefits dams offer to communities.

For 30 years, the federal government has been working to protect Americans from dam failure through the National Dam Safety Program (NDSP). The NDSP, which is led by the Federal Emergency Management Agency (FEMA), is a partnership of the states, federal agencies, and other stakeholders to encourage individual and community responsibility for dam safety.

While Kingsley Dam, which impounds the largest reservoir in Nebraska, is the primary focus of Central’s dam safety efforts, Central also has prepared emergency action plans for dams impounding Jeffrey Lake and Johnson Lake.

The possibility that Kingsley Dam (or Jeffrey or Johnson dam) will fail is extremely remote, but Central would like the public to know that it is prepared in the event of an emergency that threatens the integrity of its dams.

Central updates and revises each of its emergency action plans (EAP) annually and distributes the revised plan to a designated list of local, state and federal entities. The purpose of the EAPs is to provide maximum early warning to all persons downstream of the dam involved in the unlikely event of a failure (catastrophic or otherwise) of the structure. In addition to providing early warning, Central’s objective is to minimize or eliminate danger to people and property downstream.

EAPs contain information pertaining to how potential conditions that could cause or signify an emergency situation and steps to follow to evaluate those conditions. Such conditions include inordinately high flows, adverse weather conditions, and any situations discovered during routine inspections of the structures.

Central’s dams are inspected regularly by well-trained employees, annually by Federal Energy Regulatory Commission (FERC) personnel, and at five-year intervals by independent engineering consultants. Central also conducts functional exercises of the EAPs every five years – as required by the FERC — that involve representatives from the numerous agencies that would be involved. A functional exercise for Kingsley Dam is scheduled to take place at Central’s Gothenburg Division headquarters on June 10.

So you can rest easy tonight knowing that you probably don’t have to worry about failure of one of Central’s dams, but also that plans are in place to respond to such a calamity … just in case.

Visit http://engineeringstrongersafer.net/ for more information on National Dam Safety Awareness Day.

Additional information on national dam safety is available at: www.fema.gov/protecting-our-communities/dam-safety

 

Help Prevent an Invasion: Clean, Drain and Dry to Keep Invasive Aquatic Species Out of Nebraska Waters

Help Prevent an Invasion:  Clean, Drain and Dry to Keep Invasive Aquatic Species Out of Nebraska Waters

A small aquatic species, not much bigger than your thumbnail, poses a threat to Nebraska’s lakes, reservoirs and associated power-generating facilities.  Once established, the critters are extremely difficult and expensive to remove.

The creature is the zebra mussels (and their relative, the quagga mussel).  But Nebraska is not without defenses.  As the Memorial Day weekend — and the summer recreation season — approaches, boaters and recreation-seekers can help by simply cleaning, draining and drying a boat, trailer and related equipment to help prevent the invasion.

The zebra mussel has caused enormous problems in other parts of the country and has been detected in Nebraska in a lake at Offutt Air Force Base and on a dock on the South Dakota side of Lewis & Clark Lake.  Evidence of zebra mussels was also discovered on a boat and trailer at Harlan County Lake, although the specimens had died before the boat entered the water.  Whether it spreads to other lakes and rivers depends to a large degree on the public’s vigilance.  The mussels are one of many invasive species found in various lakes and rivers that can cause damage to boat motors and clog cooling water intakes at power plants.

quagga_mussels_3

Pipes clogged by accumulation of quagga mussels.

The Central Nebraska Public Power and Irrigation District uses water to generate electricity at the Kingsley Hydroplant at Lake McConaughy and also at three hydroplants along the Supply Canal between North Platte and Lexington.  In addition, the Nebraska Public Power District uses water from Lake McConaughy to cool equipment at Gerald Gentleman Station near Sutherland, and to produce power at the North Platte Hydroelectric Plant.  Preventing aquatic invasive species from fouling intake pipes and other equipment is important to continuing Nebraska’s ability to provide low cost, reliable electricity.

“We’ve seen the devastation that zebra mussels have done to water bodies in other states,” said Central Senior Biologist Mark Peyton.  “They dramatically change the fishery and natural balance of the lake or river.  What’s more, when they are in a system like the Platte River, it would be next to impossible to prevent them from infesting all the other water bodies associated with that system.

“Once a body of water is contaminated, monetary resources that could be used to improve and enhance recreational opportunities and wildlife value at the lakes are used instead to clean up and contain the mussels.  All in all, the mussels simply are not good for the system or for the people using the system.  We hope that people who use the lakes in Nebraska don’t become complacent about the threat because it’s out there, it’s real.”

A freshwater mollusk native to eastern Europe and western Asia, the zebra mussel — so named for its striped shell — was first detected in North America in 1988 in Lake St. Clair, a small lake between Lake Huron and Lake Erie.  The first specimens probably arrived in the ballast water of ships that sailed from a freshwater port in Europe.  It has since spread throughout the Great lakes region and to river systems in the Midwest, including the Ohio, Illinois, Arkansas, and Mississippi rivers.

How can such a small mollusk create such problems?  First, they reproduce prolifically.  A single female, which has a life span of up to five years, can lay more than a million eggs during a single spawning season.  Second, the mussels anchor themselves to hard surfaces in huge numbers.

Water intake pipes at factories, water treatment plants, and power plants have been clogged by the buildup of mussels, requiring difficult and expensive removal.  Beyond industry, zebra mussels can infest boat hulls and motors, docks, lifts and any other structure in the water.  The shells of dead mussels can accumulate in great quantities on swimming beaches, the sharp edges posing a threat to swimmers’ feet.

In addition, because they feed by filtering algae and plankton from the water, they can disrupt the food chain at its base.

A relative of the zebra mussel, the quagga mussel, has been discovered at Julesburg Reservoir in the South Platte Basin, less than 50 miles from Lake McConaughy.  The quagga poses the same threat to industry and recreation as the zebra mussel and has been found in many western lakes.  Nationwide, the economic impact of the mussels comes to billions of dollars.

Karie Decker, formerly the coordinator for the Nebraska Invasive Species Project and now an assistant division administrator for the Nebraska Game and Parks Commission’s Wildlife Division, said, “Everyone who uses our lakes for any reason, be it recreation, irrigation, or power production, has a stake in preventing the spread of these species.  Quite literally, they can ruin a lake.”

She said there would be no way to eradicate the mussels if they gained a foothold in Lake McConaughy.

“We could only hope to contain them and even that would be expensive for Nebraska,” she said.

At the root of the state’s effort to educate the public about the threat posed by the mussels is the slogan, “CLEAN. DRAIN. DRY.”  Lake visitors are urged to clean, drain and dry any watercraft and recreational equipment before putting them into the water.

“Inadvertent human transport is the main pathway for introducing the mussels to other lakes,” Decker said.  “We want to make sure people aren’t transporting water that may contain larvae from one lake to another in boats, live wells, bait buckets, waders, or even vegetation attached to boat trailers.”

Decker said it doesn’t take long to inspect boats.  The more difficult task, she said, is simply making people aware of the need to do so and getting them to follow through with regular inspections.

The public is the only line of defense and Nebraska needs help to repel the invader.  For more information about the invasive mussels, visit the Nebraska Invasive Species Project’s web site at http://snr.unl.edu/invasives.

Central Hosts Stakeholder Meetings

Central Hosts Stakeholder Meetings

By Jim Brown, CNPPID Land Administrator

NGPC's Colby Johnson addresses attendees at the Ogallala Stakeholder Meeting.

NGPC’s Colby Johnson addresses attendees at the Ogallala Stakeholder Meeting.

Stakeholder meetings were held recently to present modifications to permitting processes and regulations that are being contemplated by Central. This is the first year for these meetings, which were held at Gothenburg, Ogallala, and Lexington. The purpose is to allow stakeholders (cabin-owners and members of the public who use District lakes) the opportunity to provide feedback on current issues, to meet Central staff, and to be part of the process of improving the program.

Presentations about Central’s operations and permitting were made by Central staff members at all meetings and staff from the Nebraska Game and Parks Commission gave a presentation about park improvements at Lake McConaughy park improvements during the Ogallala meeting. Contact information for appropriate personnel was provided at all three meetings and attendees were invited to share constructive opinions and improvements to the program with an emphasis in areas of safety, environmental impacts, and neighbor relations as they relate to the permitting program. Central staff will consider all suggestions and weigh them against mandatory requirements of the Federal Energy Regulatory Commission license, the Land and Shoreline Management Plan, and any other local, state, or federal regulations and potentially incorporate suggestion that meet the requirements.

Central will continue to accept comments and suggestions until early May, at which point the comments will be reviewed with the goal of submitting the update to the District’s permitting procedures as soon as possible. If you would like to provide a suggestion for improvement, send an email to jbrown@cnppid.com.

 

Johnson Lake Drawdown Allows for Clean Up

Johnson Lake Drawdown Allows for Clean Up

Central decided to take advantage of the low water levels at Johnson Lake and do some shoreline maintenance work. As the Nebraska Game and Parks Commission worked to complete their Angler Access Project near the inlet at Johnson Lake, the water levels remained around eight feet lower than normal through most of October. This drawdown allowed cabin owners to clean up shoreline areas and also allowed Central to do some shoreline work.

Kent Aden uses his personal utility vehicle to spray an aquatic herbicide on the shoreline at Johnson Lake.

Kent Aden uses his personal utility vehicle to spray an aquatic herbicide on the shoreline at Johnson Lake.

Kent Aden is shown here testing a new aquatic herbicide in attempt to control the sago pondweed, which has been a concern for many lake residents. According to the USDA website, the sago pondweed plant is beneficial for wildlife and erosion control, but can become overgrown, and should be controlled in lakes commonly used for recreation and irrigation¹.

1. Sago Pondweed Fact Sheet. Retrieved from: http://plants.usda.gov/factsheet/pdf/fs_stpe15.pdf.

 

4th of July Weekend at Lake McConaughy

4th of July Weekend at Lake McConaughy
Crowds on beaches of Lake McConaughy

Crowds on beaches of Lake McConaughy. (Photo by Nate Nielsen)

The combination of almost perfect weather and a three-day weekend – not to mention the inviting water and beaches of Lake McConaughy – produced a record number of visitors to Central’s storage reservoir over the Fourth of July weekend.

The Nebraska Game and Parks Commission reported that 181,147 visitor-days were recorded for the July 4-6 weekend. The previous record was 142,446 in 2010 when July 4 fell on a Sunday. A visitor-day is one person per day, so if a person stayed for three days, that would result in a count of three visitor-days. Using those figures, an average of more than 60,000 people were at the Lake McConaughy/Lake Ogallala recreation areas each day.

The NGPC reported that all 325 camping pads in their modern campground were occupied. Nate Nielsen, Central’s foreman at Kingsley Dam, reported that the beaches and shorelines were lined with campers and tents, in some places four and five rows deep.

The Keith County News reported that businesses catering to lake visitors, including restaurants and convenience stores, were busy throughout the weekend with large, steady crowds of customers.

Law enforcement officials reported no serious problems, although the local sheriff’s office, the State Patrol and fire and rescue crews were extraordinarily busy responding to various emergencies, accidents, traffic issues, incidents, and complaints. All in all, though, a family-friendly atmosphere predominated and fun, recreation and relaxation ruled the weekend.

Nielsen also reported that the crowds of people did an excellent job of avoiding tern and plover nesting areas. Central personnel helped patrol the areas and reported no incidents of nest disturbances.

Johnson Lake near Lexington also drew large crowds. Larry Ossenkop, clerk of the Sanitation Improvement District at the lake, used water usage figures to provide an estimate of about 6,500 people at the homes, cabins and campgrounds over the weekend. Water levels were favorable, the weather was near perfect (although Sunday’s temperatures rose to somewhat steamy levels) and the lake was busy with watercraft of all shapes and sizes.

Fourth of July

Fourth of July

4july

Fourth of July is a holiday many spend celebrating at the lake. This year, Johnson Lake events are being held on Saturday, July 5th. The day will begin with the annual boat parade 10:00 a.m. at LakeShore Marina boat docks. Sign up at LakeShore Marina C-Store from 8:00 am to 10:00 am. Immediately following the boat parade prizes will be given out.

There will also be a dock decorating contest on July 5th. Sign-up at LakeShore Marina from 8 a.m. – 12 p.m. Judging will take place in the afternoon from 2 to 4 p.m. with cash prizes. The night will conclude with a wonderful fireworks show on the lake.

As always, please use safety precautions when boating or participating in other lake activities at any lake this weekend.

Family Adventure Day at Johnson Lake

Family Adventure Day at Johnson Lake

smores-1

May 17, 2014
Family Adventure Day
10:00 am – 1:00 pm @ East Campground Johnson Lake;
Sponsored by the Nebraska Game & Parks.
Activities: Boy Scout demonstration of dutch oven cooking, s’mores, scavenger hunt, a Naturalist with displays of birds & mammals, canoeing, hunting for sandbox treasures and much more!!!


1 2