White River Watershed Assessment Project
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PHASE 1 ENVIRONMENTAL ASSESSMENT OF THE WHITE RIVER WATERSHED WHITE RIVER, SOUTH DAKOTA Topical Report RSI-1820 prepared for South Dakota Department of Environment and Natural Resources 523 East Capitol Avenue Pierre, South Dakota 57501 September 2007 PHASE 1 ENVIRONMENTAL ASSESSMENT OF THE WHITE RIVER WATERSHED WHITE RIVER, SOUTH DAKOTA Topical Report RSI-1820 prepared for South Dakota Department of Environment and Natural Resources 523 East Capitol Avenue Pierre, South Dakota 57501 September 2007 EXECUTIVE SUMMARY Project Title: White River Watershed Assessment Project Project Start Date: October 1, 2003 Project Completion Date: December 31, 2004 Funding: Total Budget: $ 80,000 Total EPA Budget: $ 48,000 Total Expenditures of EPA Funds: $ 48,000 Total Section 319 Match Accrued: $ 32,000 Budget Revisions: No Revisions Total Expenditures: $ 80,000 SUMMARY OF ACCOMPLISHMENTS The White River is the second largest western tributary to the Missouri River in South Dakota [Fryda, 2001]. It enters Lake Francis Case, a reservoir located in central South Dakota on the Missouri River, just south of Oacoma, South Dakota, and has a contributing drainage area of approximately 9,940 square miles. The largest contributing drainage area of a tributary to the White River is the Little White River, with a drainage area of approximately 1,670 square miles. The White River was listed on South Dakota’s 303(d) list of impaired waterbodies for exceedences of water-quality standards for total suspended solids (TSS) and fecal coliform bacteria. The White River flows out of northwestern Nebraska into southwestern South Dakota and follows an easterly route until it discharges into the Missouri River. Shortly after it enters the state of South Dakota, the river flows through Badlands National Park, which is famous for its rugged, steep terrain with little to no vegetation on the easily weathered side slopes. A geographic information system (GIS) sediment loss model was created using the Revised Universal Soil Loss Equation (RUSLE). This model created a relative magnitude raster image of potential sediment erosion. The results of this analysis were used to identify areas of high potential erosion and sediment loss and to ensure proper distribution of physical habitat sampling locations. Ten sites were established for assessment of physical habitat and biologic integrity following procedures presented in the U.S. Environmental Protection Agency’s (EPA) Environmental Monitoring Assessment Program (EMAP) field operating procedure [U.S. Environmental Protection Agency, 2001a]. These sites ranged in location from Crawford, Nebraska, near the headwaters, to the mouth near Oacoma, South Dakota. An index of biologic integrity (IBI) was i created for benthic macroinvertebrates and periphyton samples. A multimetric approach was used for the development of IBIs with seven metrics being used for the benthic IBI and eleven metrics used for the periphyton IBI. Regression analysis was performed between physical habitat assessment data, biological data and historic discharge, and water-quality data to identify relations between channel morphology, riparian vegetation characteristics, biologic integrity, and water quality. The White River has long been a river of special interest because of the Missouri River Reservoirs and the impact the White River might have on reservoir storage. Historical gage data were available for the White River, dating as far back as 1928 at the station near the mouth of the river, the White River near Oacoma. A statistical analysis of the historic data set was performed to characterize hydrologic conditions in the watershed. The hydrology of the watershed was analyzed at 19 long-term gage stations for stream discharge. Water-quality data were also analyzed at nine stations, with TSS and fecal coliforms being the focus. No new discharge or water-quality data were collected for this project. The data suggest the White River can be broken down into three distinct reaches: (1) from the headwaters to the confluence of Willow Creek, roughly 5 miles downstream of the gage station near Oglala; (2) from Willow Creek to the confluence of the Little White River; and (3) from the confluence of the Little White River to the mouth of the river near Oacoma, South Dakota. These reaches are shown in Figure ES-1. Reach 2 in and around Badlands National Park, was identified as the transitional and critical reach by all methods of analysis. In this reach, the river receives a large percentage of its TSS and fecal coliform load. The physical habitat and river morphology change considerably with biologic integrity degrading. The confluence of the Little White River also represents a second change in the White River. The measured physical habitat changed slightly, mainly regarding riparian vegetation. Also, the fecal coliform concentrations are less below this location while the general hydrology of the river changes slightly. Because of the large natural background of TSS in this system, the TSS standard of 158 milligrams per liter (mg/l) is not attainable. Best management practices (BMPs) will only reduce the TSS loading a minimal percent. BMPs for fecal coliforms can be implemented to attain the water-quality standard of 2,000 colony-forming units per 100 milliliters (cfu/100 ml). Suggested BMPs for fecal coliform reduction, such as a grazing management system, off-site water, and riparian vegetation stabilization, will also have the potential to reduce the TSS loading. ii RSI-1465-04-001 Figure ES-1. Reach Definitions. ACKNOWLEDGEMENTS Cooperation and input from the following organizations and people are greatly appreciated. Without their support, this project would have been difficult to complete. • South Dakota Department of Environment and Natural Resources —Bob Smith —Gene Stueven • South Dakota School of Mines and Technology —Dr. Scott Kenner —Dr. Thomas Fontaine • United States Geological Survey —Joyce Williamson • Mellette County Conservation District —Kara Krogman iii • Badlands Resource, Conservation and Development (RC&D) —Geri Livermont —Gayle Kocer • South-Central RC&D —Theresa Benda • Bureau of Indian Affairs —Paul Hoffman • Counties of and cities within the White River Watershed. iv TABLE OF CONTENTS 1.0 INTRODUCTION................................................................................................................ 1 2.0 PROJECT GOALS, OBJECTIVES, AND TASKS ........................................................ 4 2.1 GOALS........................................................................................................................... 4 2.2 OBJECTIVES AND TASKS ........................................................................................ 4 2.3 PLANNED AND ACTUAL MILESTONES, PRODUCTS, AND COMPLETION DATES........................................................................................................................... 12 2.4 EVALUATION OF GOAL ACHIEVEMENT ............................................................. 12 3.0 DATA ANALYSIS, METHODS, AND RESULTS.......................................................... 14 3.1 WATERSHED HYDROLOGY AND WATER QUALITY .......................................... 14 3.1.1 Precipitation....................................................................................................... 14 3.1.2 Hydrologic Analysis ........................................................................................... 15 3.1.2.1 White River Hydrology Summary ..................................................... 21 3.1.2.2 Little White River Hydrology Summary........................................... 21 3.1.2.3 Baseflow-Dominated Gage Station.................................................... 22 3.1.2.4 Event-Dominated Gage Station......................................................... 22 3.1.2.5 Mix Flow Regime-Dominated Gage Stations.................................... 22 3.1.3 Water-Quality Analysis..................................................................................... 26 3.1.3.1 Exceedence Analysis........................................................................... 28 3.1.3.2 Load Duration Curves ........................................................................ 28 3.1.3.3 Annual Load Estimates...................................................................... 30 3.1.3.4 Fecal Coliform Source Tracking ........................................................ 32 3.1.3.5 Trend Analysis .................................................................................... 37 3.1.4 Water-Quality Results....................................................................................... 37 3.1.4.1 Crawford .............................................................................................. 37 3.1.4.2 Whitney................................................................................................ 38 3.1.4.3 Chadron NW........................................................................................ 38 3.1.4.4 Chadron ............................................................................................... 39 3.1.4.5 Bordeaux Creek................................................................................... 39 3.1.4.6 Oglala................................................................................................... 39 3.1.4.7 Kadoka ................................................................................................. 40 3.1.4.8 White River Near White River..........................................................