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C. A. Niehus

Publications and source records attributed to C. A. Niehus.

8 recordsLinked to original sources
USGS1997

Characterization of stormwater runoff in Sioux Falls, South Dakota, 1995-96

The Kenai River in southcentral Alaska is an economically important salmon river generating as much as $78 million annually in direct benefits. Resource-management agencies are concerned that increased sedimentation and loss of streamside cover associated with accelerated erosion rates caused by boat activity may threaten salmon returns to the river. Bank loss and boat activity were characterized during 1996 along 67 miles of the Kenai River, including a segment of the river several miles long where boat activity is restricted to non-motorized uses. Bank loss in the non-motorized segment of the river was about 75 percent less than that observed in the highest boat-use area of the river and 33 per cent less than that observed in the lowest boat-use area of the river. Dates of peak boat activity coincided closely with chinook salmon returns to the Kenai River and with peaks in measured bank erosion. The boat activity period began in late May, peaked on weekend days in mid-July, and declined in early August. Observed boat traffic on the Kenai River included boats from 10 to 26 feet in length that transported 1 to 8 passengers. The most commonly observed boats were between 16 and 20 feet long and carried 4 or 5 passengers. The number of boats operated by commercial fishing guides represented 40 percent of the boats counted by the Alaska Department of Natural Resources, 55 percent of the boats counted by the Alaska Department of Fish and Game, and 57 percent of those recorded by observers during this study. The maximum boat activity and the maximum bank loss were measured at the RW's Campground study site about 16 river miles upstream from the mouth of the Kenai River. Between July 12 and September 10, 1996, more than 20,100 boats traveled by this site and the streambank along the inside of the meander bend was undercut to a depth of 45 inches at one measuring point. Boat activity and bank loss were greatest in areas of the river between about river miles 9 and 18 and river miles 39 and 46. These two segments of the river are popular residential and fishing areas and have banks composed of non-cohesive soils. In addition, a meandering, un-armored channel makes the banks along these two segments susceptible to erosion. The Kenai River in southcentral Alaska is an economically important salmon river generating as much as $78 million annually in direct benefits. Resource-management agencies are concerned that increased sedimentation and loss of streamside cover associated with accelerated erosion rates caused by boat activity may threaten salmon returns to the river. Bank loss and boat activity were characterized during 1996 along 67 miles of the Kenai River, including a segment of the river several miles long where boat activity is restricted to non-motorized uses. Bank loss in the non-motorized segment of the river was about 75 percent less than that observed in the highest boat-use area of the river and 33 percent less than that observed in the lowest boat-use area of the river. Dates of peak boat activity coincided closely with chinook salmon returns to the Kenai River and with peaks in measured bank erosion. The boat activity period began in late May, peaked on weekend days in mid-July, and declined in early August. Observed boat traffic on the Kenai River included boats from 10 to 26 feet in length that transported 1 to 8 passengers. The most commonly observed boats were between 16 and 20 feet long and carried 4 or 5 passengers. The number of boats operated by commercial fishing guides represented 40 percent of the boats counted by the Alaska Department of Natural Resources, 55 percent of the boats counted by the Alaska Department of Fish and Game, and 57 percent of those recorded by observers during this study. The maximum boat activity and the maximum bank loss were measured at the RW's Campground study site about 16 river miles upstream from the mouth of the Kenai River. Between July 12 and September 10, 1996, more than 20,10

Water-Resources Investigations Report↗
USGS1996

Estimation of flood flows on the Big Sioux River between Akron, Iowa, and North Sioux City, South Dakota

This report presents estimated flood flows for specified frequencies at selected locations on the Big Sioux River between the Akron, Iowa, streamflow-gaging station and North Sioux City, South Dakota. The selected locations include: at the Akron gaging station, downstream from the Richland-Westfield Creek Basins, downstream from the Brule Creek Basin, downstream from the Upper West Boundary Big Ditch and Rock Creek Basins, downstream from Broken Kettle Basin, and downstream from North Sioux City. The flood flows for the 10-, 50-, 100-, and 500-year recurrence intervals will be used to support a Federal Emergency Management Agency Flood Insurance Study. Four methods were used to estimate the flood flows. The first method involved the use of drainage-area ratios raised to specified exponents to transfer the flood-frequency relation from the Akron gage to the selected downstream locations. The second method was a flood-frequency analysis based on a summation of the Akron gaging-station peak flows and concurrent tributary daily flows from within the various study reaches. The third method was an independence/dependence analysis of the Akron gaging-station flows and the tributary flows from the various study reaches. The fourth method was a flood-frequency analysis assuming complete dependence of the Akron peak flows and the tributary peak flows from the various study reaches. Based on the various analyses that were done, the drainage-area-ratio method best estimated the flood flows for the Akron to North Sioux City reach of the Big Sioux River. The best estimates of 10-, 50-, 100-, and 500-year flood flows at the location downstream from North Sioux City are 35,300, 70,400, 89,100, and 142,000 cubic feet per second, respectively.

Water-Resources Investigations Report↗
USGS1994

Water resources of Lincoln and Union counties, South Dakota

Water resources of Lincoln and Union Counties occur as surface water in streams and lakes and ground water in ten major glacial and one major bedrock aquifers. The major surface-water sources are the Missouri and Big Sioux Rivers. Glacial aquifers contain about 4 million acre-feet of water in storage; 1.5 million acre-feet are contained in the Missouri aquifer. The Wall Lake, Shindler, and Upper Vemillion-Missouri aquifers are deeply buried, confined aquifers with average thicknesses ranging from 31 to 41 feet. The Harrisburg and Big Sioux aquifers are shallow, water-table aquifers with average thicknesses of 26 and 28 feet, respectively. The Parker-Centerville, Newton Hills, and Brule Creek aquifers are buried, confined aquifers with average thicknesses ranging from 33 to 36 feet. The Lower Vermillion-Missouri aquifer is a buried, confined aquifer with an average thickness of 99 feet. The Missouri aquifer is confined in the northeastern portion of the aquifer and is a shallow, water-table aquifer elsewhere with average cumulative thickness of 84 feet.

Water-Resources Investigations Report↗