Document Type

Thesis - Open Access

Award Date


Degree Name

Master of Science (MS)

Department / School

Civil Engineering


The Big Sioux River originates in northeastern South Dakota and in general flows southward to Sioux City, Iowa, where it joins the Missouri River. A major portion, 69 percent, of the Big Sioux River Basin is located in South Dakota. The remaining 31 percent of the basin's 9,570 square miles is distributed almost equally between the states of Iowa and Minnesota. The climate of the Big Sioux River Basin is described as midcontinental, subhumid, and with rapid fluctuation of temperature. Temperatures of over 100° Fare not uncommon during summer months and temperatures frequently fall below 0° F during the winter months. Average temperatures at Sioux Falls, South Dakota, for the months of· January and July are 15.2° and 74.3° F, respectively. This study is concerned with that reach of the Big Sioux River located between the Sioux Falls wastewater treatment plant and the Klondike Bridge. The reach measures 32.0 river miles and has an average gradient of about 2.0 feet per mile. From 18.4 river miles below the treatment plant to its concurrence with the Missouri ·River, the Big Sioux forms the border between South Dakota and Iowa, and thus is classified as an interstate stream. The Sioux Falls wastewater treatment plant is located 1.0 miles downstream from the Falls of the Big Sioux and immediately downstream from the spillway of the Big Sioux River diversion channel. Aeration of the river water occurs at both the falls and spillway. As a result of this aeration, the dissolved oxygen content of the river would be relatively high at the treatment plant outfall.

Library of Congress Subject Headings

Water quality

Water -- Analysis

Big Sioux River (S.D.)

South Dakota State University Theses



Number of Pages



South Dakota State University