Question: What shallow water table aquifer is located near the county seat of Keith County, Nebraska?

Passages:
<P3-S0> Keystone is an unincorporated community and census-designated place in central Keith County, Nebraska, United States. <P3-S1>  It lies along local roads near the North Platte River, northeast of the city of Ogallala, the county seat of Keith County. <P3-S2>  Its elevation is 3,100 feet (945 m). <P3-S3>  Although Keystone is unincorporated, it has a post office, with the ZIP code of 69144. Souris Beach Provincial Park is a day-use provincial park located near the town of Souris in eastern Prince Edward Island, Canada.  The beach is very shallow, allowing visitors to walk several hundred feet from shore on an all sand bottom.  The shallow water also results in the waters at this beach being warmer, as a result of warming by the sun, than other Island beaches where depths increase more quickly. Dune Dam is a long sand dune that lies at the western end of Chaco Canyon, New Mexico, near the confluence of the Chaco and Escavada Washs.  The dune was created by winds that brought sand up the Chaco River.  When the dune was large enough, it dammed the Chaco Wash and created a small and shallow lake near the Ancestral Puebloan great house, Penasco Blanco.  Archeological evidence suggests that the dune was breached around 900 CE.  Chacoans filled the breach with masonry sometime in the early 11th century, and built an accompanying reservoir lined with stones that was visible until 1920.  The dam stopped Chaco Wash from further deepening, which helped raise the water table in the canyon, aiding Chacoan farming.  The absence of a lacustrine plain behind the dam led geologist Stephen A. Hall to question this interpretation. Kingsley Dam is located on the east side of Lake McConaughy in central Keith County, Nebraska, and is the second largest hydraulic fill dam in the world.  It was built as part of the New Deal project.  The dam is 162 ft tall, 3.1 mi long, and 1100 ft wide at its base.  On the east side of the dam is Lake Ogallala and on the south side is the Kingsley Hydroelectricity Plant.  The Nebraska Game and Parks Commission and Central Nebraska Public Power and Irrigation District are also located in this area.  Kingsley Dam, the Kingsley Hydroelectricity Plant, the Morning Glory Spillway, and the Outlet Tower – a large structure near the dam used to release water from the lake – are main visual icons of Lake McConaughy. Lemoyne is an unincorporated community and census-designated place in northern Keith County, Nebraska, United States.  It lies along Nebraska Highway 92 on the northern shore of Lake C.W. McConaughy, north of the city of Ogallala, the county seat of Keith County.  Its elevation is 3,333 feet (1,016 m).  Although Lemoyne is unincorporated, it has a post office, with the ZIP code of 69146. <P1-S0> Keith County is a county located in the U.S. state of Nebraska. <P1-S1>  As of the 2010 census, the population was 8,368. <P1-S2>  Its county seat is Ogallala. The Ogallala Aquifer is a shallow water table aquifer surrounded by sand, silt, clay and gravel located beneath the Great Plains in the United States.  One of the world's largest aquifers, it underlies an area of approximately 174000 sqmi in portions of eight states (South Dakota, Nebraska, Wyoming, Colorado, Kansas, Oklahoma, New Mexico, and Texas).  It was named in 1898 by geologist N. H. Darton from its type locality near the town of Ogallala, Nebraska.  The aquifer is part of the High Plains Aquifer System, and rests on the Ogallala Formation, which is the principal geologic unit underlying 80% of the High Plains. Flatwood is a soil series with impaired drainage that occurs in the southeastern United States.  Flatwood soils are upland soils formed from marine sediments.  A shallow water table plays a role in soil formation, typically the water table is only a few feet deep and fluctuates during the year.  Flatwood soils are classified in USDA soil taxonomy as fine, mixed, semiactive, mesic Aquic Hapludults. Ogallala is a city in Keith County, Nebraska, United States.  The population was 4,737 at the 2010 census.  It is the county seat of Keith County.  In the days of the Nebraska Territory, the city was a stop on the Pony Express and later along the transcontinental railroad.  The Ogallala Aquifer was named after the city. Ingram–Schipper Farm is a historic farm complex located near Boonsboro, Washington County, Maryland, United States.  It is a two-story, four-bay Flemish bond brick dwelling with white trim and water table.  The house features a Victorian period flat-roofed one-story porch and a slate roof.  The property includes a number of early outbuildings, including a brick kitchen and wash house, three log buildings, one of which has a fireplace and appears to have been a dwelling, and a large stone barn.

Supporting sentences:
 It is the county seat of Keith County.  The Ogallala Aquifer was named after the city. The Ogallala Aquifer is a shallow water table aquifer surrounded by sand, silt, clay and gravel located beneath the Great Plains in the United States.