Appendix 1 - Niobrara River Background.pdf

8/10/2019 Appendix 1 - Niobrara River Background.pdf

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Appendix 1

Niobrara River Background


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Introduction

Understanding the Niobrara River and the habitat requirements of its aquatic and avian fauna

requires a study of the past as well as the present, this appendix is being written with that goal

in mind. This appendix is intended as a lay summary of water sources, geology, agricultural and

recreational development in the Niobrara River basin to advance an understanding of theNiobrara River. The river, which is a vital economic, ecological and scenic component of

northern Nebraska, needs to be understood as fully as possible to protect and ensure the

common welfare of the flora, fauna and the elements of society that thrive upon or near its

flowing reaches. The Niobrara watershed, a sub-basin of the Missouri watershed, covers

approximately 32,600 km2of which 90% lies within northern Nebraska and the remaining

portions extend into eastern Wyoming and southern South Dakota. The Niobrara River, the

longest river in Nebraska, begins as a small stream in eastern Wyoming and ends approximately

901 km (560 mi) downstream at the confluence with the Missouri River in the town of Niobrara.

The Niobrara River is used in many different ways to meet the needs of those living in the

watershed. Some of these uses include hydro power generation, irrigation of agricultural crops,water supply for ranches, water for domestic and recreational purposes and as a resource for

native flora and fauna. Along with these needs of society the Niobrara River is also an integral

part of the ecological processes which have been slowly working for millions of years to make

this region the unique meeting spot for the diverse ecological zones found within the Great

Plains.

Prior to the creation of the state of Nebraska, the area was home to numerous tribes such as

the Sioux or Oceti Sakowin and the Ponca. The area these tribes called home also encompassed

the Black Hills of South Dakota. The Ponca people called the river N Ubththa khe meaning

water spread-out horizontally and in the late 1800s the French named it L'Eau qui Court

which means running water. The indigenous peoples living on the plains were nomadic and

followed migrating bison, moving as the seasons dictated. When the native tribes of the West

met the Spanish in the 1600s, horses were introduced and these tribes became even more

mobile. The Nebraska territory was derived from a small portion of the Louisiana Purchase, a

transaction with France completed in 1803. Around this time, traders begin to arrive in the

area, where they trapped and traded along the river near its confluence with the Missouri

River. In the mid-1800s, people began moving west in greater numbers on what became the

Oregon Trail which ran along the Platter River. When gold was discovered in California in 1849,

people began moving through in greater numbers to seek their fortunes. Nebraska officially

became a territory through the Kansas-Nebraska Act of 1854 (Klajic, 2000). The rapid migration

to the area caused intense pressure on the native indigenous population and interactions

became increasingly violent. By the late 1800s, most of the indigenous tribes were removedfrom their native lands and placed on distant reservations. Pioneer expansion and

infrastructure modernization throughout Nebraska shortly followed this period. The Fremont,

Elkhorn and Missouri Valley Railroad Company built several lines of tracks, some near the

Niobrara River, thus improving access and encouraging increased settlements. The railroad also

opened the rich soils and grasslands of western Nebraska to farmers. With the passing of the

Homestead Act in 1862, the grasslands were divided and made available for farming and


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ranches within the Niobrara Watershed. From the onset, farmers in this region saw the need

for augmenting the regions natural precipitation with an irrigation system to supply their crops

on a regular basis. Irrigation has been an integral part of the history of Nebraska and critical to

the people farming in this arid portion of the country.

Today, the uses of the Niobrara River are similar to those in the mid twentieth century, but now

technology has allowed society to utilize the same finite resources of the Niobrara River at a

larger scale. The dominant land use in the basin today is cattle ranching (>70%), but row crops

account for 20% of the watershed and are concentrated in areas where adequate water sources

are available (Peters et al., 2006). Most of the land in the region is privately held; however,

private groups or state and federal agencies hold several large tracts of land in a conservation

status. These areas include: the Niobrara National Scenic River, the Fort Niobrara National

Wildlife Refuge and the Nature Conservancys Niobrara RiverValley Preserve.

The Niobrara River borders and partially bisects the northern limits of the Nebraska Sandhills.

The Nebraska Sandhills are the largest intact sand dune complex in the Western Hemisphere

(Bleed and Flowerday, 1998). The Sandhills grasslands begin in the western portion of the basin,

while proceeding east the Sandhills give way to mixed-prairie grassland consisting of more

mesic-floral varieties (Kantak, 1995). Along the riparian zone and active channel, deciduous and

coniferous plants become the primary vegetation type. It is important to note that in many

areas along the Niobrara River, refugia for a variety of special species can be found. For

example, the north facing canyons support white birch (Betula papyrifera), primarily a Rocky

Mountain species, because of the shading and emergence of cold ground water springs (Kaul et

al., 1988). The central stretch of the Niobrara River lies in an area considered to be a biological

meeting place of the Great Plains. This area has been recognized by the US government for its

unique characteristics and a few large tracts of land have been set aside for conservation and

historical importance.

Recognizing the significance of the resources provided by the Niobrara River, the Nebraska

Department of Natural Resources has divided the Niobrara River basin into three distinct

districts. The Upper Niobrara White Natural Resources District (UNWNRD) contains portions of

the Niobrara and White Hat basins located in Dawes, Sheridan and Sioux Counties. The Middle

Niobrara Natural Resources District (MNNRD) bordering South Dakota lies in north central

Nebraska along the middle stretch of the Niobrara River. The District is made up of the northern

two-thirds of Cherry County, western Keya Paha, northern Brown, and a small portion of

western Rock County (USDA NRCS). The Lower Niobrara Natural Resources District extends east

from the MNNRD to the confluence of the Missouri River (NRDNET). Each of these three

districts manages the resources which fall within its boundaries. The Niobrara River reached a

critical point in 2008 when the Nebraska Department of Natural Resources labeled most of theriver as, fully appropriated.However, in June 2011, the Nebraska Supreme Court reversed the

January 2008 determination regarding the fully appropriated designation due to concerns

regarding the quality of methodology used (Schneider, 2011).

Source of Water for the Niobrara River

The Niobrara Rivers water source is primarily ground water seepage from the underlying

geological formations. Originating from the impermeability of the Pierre Shale and the


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proximity of the riverbed to bedrock, the two main aquifers supplying water for the Niobrara

River Basin are the Arikaree and the Ogallala. The Arikaree lies in the western portion of the

basin and beneath the immense Ogallala Aquifer (Figure 1-1), which lies under portions of eight

different states. The majority of area of the state of Nebraska sits on top of the Ogallala

Aquifer. The Arikaree is comprised predominantly of sandstone, siltstone, shale, and silty clay.

The Ogallala Aquifer consists of fine to medium sandstone and silty clay material (Long et al.,2003). The material comprising the Ogallala Aquifer dates from approximately 2 to 6 million

years ago. The gradual erosion of the Rocky Mountains provided the base material for the

aquifer, which was then covered by windblown and alluvial sediment that filled the ancient

valleys and channels of the present Niobrara River Basin. In the western portion of the Niobrara

River, a majority of tributaries begin as seeps and result in many cold-water streams. Further

east, within the National Scenic portion of the Niobrara, these seeps create numerous

waterfalls. Nearly 230 waterfalls exist along this reach of the river in all. Water level

fluctuations in the river are limited in the west because of the consistent aquifer discharge. In

the east however, water fluctuations increase with changes in soil type, precipitation, and

distance in relation to the aquifer (Istanbulluoglu, 2008).

Figure 1-1: Shape and size of the Ogallala Aquifer system. Figure produced from GIS data by the USGS

and published in Open File Report 00-300 (USGS OFR 00-300).


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Precipitation and groundwater contribution are vital components to the hydrography of the

Niobrara River. However, it is perhaps the use of that water that remains the cornerstone for

sustainability of the system. Anthropogenic diversions within the basin include dams and

subsequent irrigation reservoirs and groundwater wells. All of these uses have the ability to

change the river and the surrounding ecosystem and it is important to understand the effects

that they can have.

Geology

The Niobrara River basin consists of a variety of geological formations ranging in age from the

Cretaceous bedrock of 135 million years ago (mya) to the eolian loess of less than 1000 years

ago. These differences produce a basin that is old and new at the same timegeologically

speaking. The base formation underlying the river and the entire basin are Cretaceous and

Tertiary bedrock. Lying above the bedrock is the Niobrara Chalk formation. This formation is

present and visible in the vertical bluffs from the mouth until approximately the Norden Bridge

(Conservation and Survey Division, 1986). Downstream from the Norden Chute, Pierre Shale

layers become visible and are in closest proximity to the water. Subsequent formations in thebasin, Rosebud (24-28 mya), Valentine (11-14 mya), and Ash Hollow (6-11 mya) can also be

seen above the Pierre Shale. These formations along with other geologic activity during the

Quaternary Period (0.0-38 mya) formed the basis of the Ogallala group and the foundation of

todays Ogallala aquifer (Skinner & Hibbard, 1972). The Ogallala aquifer is a vital water source

for Nebraska, as well as the source of the Niobrara Rivers base flows. Capping the Niobrara

River basin is a mix of several different sedimentary formations including: Petti-john, Duffey,

Long Pine, and Keim. This group of terminal formations is heavily incised due to fluvial action on

gravel and fine sediments and is found in varying amounts (Elders, 1969; Bristow, 1999).

Additionally, eolian sands cover much of the area but are restricted primarily to the southern

banks and uplands of the Niobrara River basin. Soil make-up for the basin is varied, but

primarily consists of Valentine (Elders, 1969). Overall the Niobrara River basinsgeology is

varied in age, composition, and level of influence. Each component of the geology combines to

establish unique properties that are found nowhere else in Nebraska. Cross-section illustrations

of the geologic formations of the Niobrara River valley can be found in Johnsgard et al.(2007).

Figure 1-2illustrates the current geological bedrock formations within the Rushing Rivers study

area as well as those for the entire state. The Ogallala bedrock formation dominates the study

area, but what is interesting and gives the Niobrara River some of its distinctive character, as

noted above, are the bedrock formations which lie above the Ogallala Aquifer and in some

cases directly below the river itself. Some of these areas are highlighted by thick black lines in

Figure 1-2because they are difficult to see due to the size of the study area.


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Box Butte Dam is a zoned, earth-filled structure with a rock face which is 87 ft tall and 5,508 ft

in length. It is located approximately 16 km (10 mi) north of Hemingford, Nebraska in Box Butte

County. The reservoir for the dam has a total capacity of 31,060 acre-feet and a surface area of

1,600 acres. The Dunlap Diversion Dam is a concrete weir wing structure approximately 12 ft

tall and 80 ft in length. It is located 12.9 km (8 mi) downstream from Box Butte Dam and is used

to divert up to 220 cfs of water over 19 km (12 mi) through the Mirage Flats Canal System. TheMirage Flats Canal System is located off the Dunlap Diversion and has a length of approximately

21 km (13.2 mi) and a carrying capacity of 220 cfs. The canal system delivers the diverted water

to project farming units totaling over 11,000 acres. Crops for the Mirage Flats Project include

alfalfa, beans, barley corn, oats, and wheat. Recreation opportunities are also available as a

result of the project. Some of these activities include camping, boating and fishing at the

reservoir. The Nebraska Game and Parks Commission manage the recreational activities at the

reservoir. In addition to the services listed above, the dam also provides a measure of flood

control.

Merritt Dam

Merritt Dam (Figure 1-3) on the Snake River is located approximately 19 km (12 mi) southwest

of Valentine in the northern Sandhills region of Nebraska and began delivering water in 1965.

The dam is named after Mel Merritt, who was a strong supporter of the irrigation possibilities

the Snake River provided and a conservation officer for the State of Nebraska. The components

that provide farmland to be irrigated in the vicinity of Ainsworth are the Merritt Dam,

Ainsworth Canal and the Ainsworth Lateral System. The dam has the ability to divert water

from the Snake River into the canal which sends diverted water to the lateral system which

then distributes the water to various farms within the Ainsworth Irrigation District. The earth

filled dam is 126 ft tall and is 3,222 ft in length. The dam is operated by Ainsworth Irrigation

District and provides water for the Ainsworth Irrigation District which is located in Brown and

Rock Counties. The water used for irrigating purposes is moved from the reservoir through theAinsworth Canal approximately 64 km (40 mi) to the Ainsworth Irrigation District providing

water for 298 farms with a total acreage of approximately 34,540 acres of cropland with a value

of more than $11,500,000 (1992 dollars, Simonds (1999)). The total acreage of farm lands

within the district grew until 1977 and since has remained fairly consistent. Up to 580 cfs of

water is diverted from the Snake River by the Merritt Dam and Reservoir to provide the water

used for irrigation purposes (Istanbulluoglu, 2008). Corn is the primary crop on project farm

lands and is grown on more than 25,000 acres. The reservoir waters and lands abutting the

reservoir are managed by the Nebraska Game and Parks Division for recreational use and

wildlife conservation purposes which bring more than 150,000 people to the area each year

(The Ainsworth Unit). The reservoir has a total capacity of over 60,000 acre/feet (U.S.

Department of the Interior, Bureau of Reclamation). Construction on the Ainsworth Canal

began in April 1962 and was completed in September 1965. The canal just under 85 km (53 mi)

in length and lined with concrete and has a capacity of 580 cfs. The Ainsworth Lateral System is

over 281 km (169 mi) long and can vary in its flow capacity between 4 -580 cfs. The Ainsworth

Lateral System was completed in June 1966.


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Cornell Dam

Cornell Dam (Figure 1-3) is named after C.H. Cornell of Valentine who was the driving force in

getting the dam built. The dam is a run-of-the-river structure completed in 1915, above the

confluence of Minnechaduza Creek and the Niobrara River. The dam is primarily concrete

totaling over 207 ft in length with a hydraulic height of approximately 10 ft. It was constructed

for the purpose of generating electricity and supplied energy to Valentine, NE. Cornell Dam was

privately operated until the early 1940s, when Nebraska enacted a statewide public power

policy. The dam and hydroelectricity plant were then operated by Nebraska Public Power

District (NPPD) until it closed operations in 1985. After the closure of Cornell Dam, NPPD

transferred the land and surrounding structures to the United States Department of the

Interior, which then became part of the Fort Niobrara National Wildlife Refuge operated by the

United States Fish and Wildlife Service (Nebraska Public Power District website).

Spencer Dam

Construction of Spencer Hydro-Dam (Figure 1-3) was completed in 1927 and operations of the

facility have been overseen by NPPD since the 1940s. The Spencer Hydro-Dam is the onlyhydroelectric facility on the Niobrara River. Spencer Dam is primarily an earthen dam

accompanied by nine spillway gates and the generator house. The total length of the structure

is approximately 3698 ft, of which 404 ft is spillway gates and the generator house and

hydraulic height for the Spencer Hydro-Dam is just over 26 ft. The hydroelectricity facility

houses two Westinghouse generators with a maximum capacity of 3000 kilowatts per hour.

River flows that move through the turbine of the hydro electrical facility vary throughout the

year with 2010 summer flows averaging 1690 cfs (SD=227 cfs). The maximum discharge for

operation is 20000 cfs.While Spencer Hydro-Dam can be classified as a run of the river dam,

it still impedes some water and substrate, creating a small impoundment upstream of the dam.

Themaximum capacity of the impoundment is 16,487 acre feet with normal storage at 5,306

acre feet. Additionally, the normal surface area of the impoundment is 1.4 square miles. The

dam is operated to match the flow of the river, but this cannot always be exact because of

routine maintenance. However, operational procedures generally match normal flow

conditions (Soenksen et al.,2010). The dam also provides the added benefit of acting as a

barrier to invasive aquatic species moving up-river from the Missouri River such as Asian carp

(Wanner et al.,2008). The hydropower facility has a 2,035 cfs hydropower water appropriation

right with priority dates of 1896, 1923 and 1942 (Aiken, 2007).

Norden Chute

The Norden Chute (Figure 1-3), located east of Valentine, marks a point where the river

transitions from a single river channel upstream to a mostly braided river system downstream.The Norden Chute is a natural fish barrier produced as a result of the river flowing over a unit of

bedrock that forms a portion of the high plains aquifer. The single channel portion of the river

upstream from Norden Chute is generally narrow with very little to no flood plain; on the other

hand, downstream from the chute the river is remarkably different having a very wide and large

flood plain. This difference can be easily seen in the aerial photography located in Appendix 3

of this report; Sites 16 through 6, from west to east, exemplify the single channel characteristics

and Sites 5 through 1 show the highly braided characteristics of the river downstream.


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Recreation

Niobrara National Scenic River

In 1991, a 122 km (76 mi) stretch of the Niobrara River became part of the USAs Scenic River

System (Figure 1-3). The National Wild and Scenic Rivers System was created by Congress under

the Wild and Scenic Rivers Act of 1968. Under this Act any river that is deemed to haveexceptional recreational, natural, scenic and cultural characteristics can be designated as a Wild

and Scenic waterway. Rivers of the National Wild and Scenic Rivers System should also be void

of impoundments, be able to support a natural flora and fauna community, be healthy for

people to utilize in a recreational capacity and retain a generous portion of their natural

condition (National Wild and Scenic Rivers System).

Under this system the National Park Service is able to develop a specific management plan for

its use and provide a level of protection the river would not otherwise have. The Niobrara

National Scenic River begins east of Valentine and flows 76 miles through north central

Nebraska. There are over 230 waterfalls on this portion of the river, which are a natural feature

attributed to the close proximity of the river and the high plains aquifer. The National ParkService has identified six different ecosystems meeting in this area. There are three forest

types: eastern deciduous, ponderosa pine and boreal forests. There are also three prairie types:

tall-grass, mixed-grass and short-grass. The rich complexity of varying ecological zones within

the area supports a large number of both plant and animal species (National Park Service). This

stretch of the Niobrara River is enjoyed by tens of thousands of visitors yearly through the U. S.

National Park Service and the many recreational outfitters located in the area.

Fort Niobrara National Wildlife Refuge

Before the first European settlers came to the Nebraskan territory the surrounding landscape

was largely dominated by grass extending for great distances with streams and rivers scattered

throughout the region. These lotic environments bordered by trees were a rich resource

supporting a host of vegetative and animal life. Fort Niobrara was built in 1879 to protect

pioneering settlers but saw little conflict during that time and was later abandoned in 1906. In

1912, President Theodore Roosevelt signed an executive order making Fort Niobrara a bird

preserve and a place to conserve bison and elk herds which were rapidly dwindling in number.

Today, Fort Niobrara National Wildlife Refuge (Figure 1-3) encompasses an area over 19,000

acres and contains within its borders the Cornell Dam and a portion of the Niobrara National

Scenic River. Fossils dating from 12 thousand to 13 million years ago have been found within

the refuge including those of three-toed horses, mastodons and giant bison. A person visiting

the refuge today can still see the remains of the foundation from where the old fort originally

stood. The refuge is home to or is visited by over 230 species of birds yearly. The geographicallocation of the fort places it in the migration route for many bird species including the

endangered whooping crane.

Valentine National Wildlife Refuge

In 1935, the 71,516 acre Valentine National Wildlife Refuge was established to protect a part of

the Sandhills region and the wildlife which falls within its boundaries. This refuge is managed as

part of the Fort Niobrara National Wildlife Refuge and is home to a portion of the Sandhills


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Prairie the last mid and tall grass prairie in the country. This prairie system was deemed a

National Landmark in 1976 due to its unique character.

Niobrara Valley Preserve

The Niobrara Valley Preserve, purchased in 1980, is the largest preserve the Nature

Conservancy owns and manages. It is situated in a portion of Brown, Cherry and Keya PahaCounties. The preserve is almost 58,000 acres and contains a 25 mile stretch of the Niobrara

River. This preserve is home to more than 500 bison, which were brought back in 1985 to help

restore the valley to its original condition before European settlement in the 1800s. The

preserve functions as a testing ground for grassland management practices to help restore the

native prairie systems, which were once an integral part of this diverse region. The preserve

also operates as a ranch for cattle grazing and wood harvesting. Through the Niobrara Valley

Preserve, the Nature Conservancy places a high importance on scientific research and

education integrating the ecological needs of the prairie system with the demands of society

(Niobrara Valley Preserve website).

Merritt Reservoir State Recreation AreaThe Merritt Dam/Reservoir complex provides recreational opportunities and wildlife

conservation management. Managed by the Nebraska Games and Parks Commission, the 71 km

(44 mi) of reservoir shoreline provides hunting, fishing, camping and water recreational

activities to thousands of visitors each year.. The recreational complex at the reservoir has eight

camping areas with more than 200 campsites available (Nebraska Games and Parks). The

recreational facilities and campgrounds are also used by visitors to the nearby McKelvie

National Forest, which is located just to the north of the dam.

Box Butte Reservoir

The Box Butte Reservoir State Recreation Area located on the 14 miles of shoreline surroundingthe Box Butte Dam and over 600 additional acres surrounding the reservoir provides many

opportunities for people to enjoy outdoor recreational activities. Visitors to the facility

managed by the Nebraska Games and Parks Commission can participate in boating, fishing,

hiking and camping (Nebraska Games and Parks). This site is also a favorite for bird enthusiasts;

over 200 species of birds have been seen at this park since 1973 (U.S. Department of the

Interior, Bureau of Reclamation).

McKelvie National Forest

This national forest is over 115,000 acres of prairie grassland and pine forests. Most of the trees

in the national forest have been planted by people to be used for harvesting purposes. The

Eastern Juniper, Scots Pine and Ponderosa Pine stands that are harvested and continuouslyreplaced have begun to spread throughout the area on their own.

Valentine State Fish Hatchery

The Valentine State Fish Hatchery built in 1912, located on Minnechaduza Creek just north of

Valentine, is one of four state operated hatcheries in Nebraska. The 700-acre facility managed

by the Nebraska Game and Parks Commission has the capability to collect and produce more

than 68,000,000 eggs a year as well as raise more than 1,000,000 largemouth bass, bluegill,


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black crappie, channel catfish and tiger muskellunge in a season (Nebraska Game and Parks

Commission).

Niobrara State Park

The state park encompasses the confluence of the Niobrara and Missouri Rivers and protects

1,640 acres of delta and the surrounding hills. The park is a popular camping site.


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in the Niobrara River Basin, Nebraska, 1980 and 2009.Journal of Environmental

Hydrology18, paper 11.

Wanner GA, Pegg MA, Shuman DA, Klumb RA. 2008. Niobrara River Fish Community

Downstream of Spencer Dam, Nebraska 2008 Progress Report. U. S. Fish and Wildlife

Service.

ONLINE RESOURCES

National Wild and Scenic Rivers System website.

http://www.rivers.gov/

Nebraska Games and Parks website.

http://outdoornebraska.ne.gov/parks/

Nebraska Natural Resource Districts website. http://nrdnet.org/DOCS/PDF/Niobrara.pdf

Nebraska Public Power District website.

http://www.nppd.com

Niobrara Scenic River, National Park Service website.

http://www.nps.gov/niob/naturescience/index.htm

Niobrara Valley Preserve website

http://www.nature.org/ourinitiatives/regions/northamerica/unitedstates/nebraska/pla

cesweprotect/niobrara-valley-preserve.xml

U.S. Department of the Interior, Bureau of Reclamation website.

http://www.usbr.gov/projects/

Appendix 1 - Niobrara River Background.pdf

Documents

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