Snake River Watershed Conditions Report

SNAKE RIVER WATERSHED CONDITIONS REPORT

Topical Report RSI-2483

Prepared by

Megan Burke Emily Javens

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prepared for

Middle-Snake-Tamarac Rivers Watershed District 453 North McKinley Street Warren, Minnesota 56762

February 2015

1935 West County Road B2, Suite 320 Roseville, MN 55113 651.788.7813

Snake River Watershed Conditions Report

EXECUTIVE SUMMARY

The Snake River Watershed Conditions Report describes the watershed’s physical characteristics, provides an overview of its water resources, and describes current water quality conditions. This includes summarizing water runoff (floods to drought), patterns in water quality, potential stressors to the biological integrity of the waterbodies, and information gaps. The development of the conditions report is the first step in building a Snake River Watershed Restoration and Protection Strategy (WRAPS). The ultimate goal of the Snake River WRAPS is to develop and implement strategies to protect waters where conditions meet water quality standards and to restore waters that are impaired. This report and subsequent WRAPS will provide additional knowledge and tools for balancing the needs of intense land uses (agriculture and urban development), including flood reduction with the preserving of ecological functions via watershed-based approaches.

Located in the Red River of the North Basin in northwestern Minnesota, the Snake River and Middle River Watersheds drain an area of 611,800 acres (or approximately 956 square miles). The Snake River flow network includes two converging rivers, with the Middle River flowing to the west across the northern portion and joining the Snake River and the South Branch of the Snake River draining lands from the southern portion of the watershed. Both rivers receive runoff from extensive networks of drainage ditches. The Snake River Watershed is managed by the Middle-Snake-Tamarac Rivers Watershed District (MSTRWD).

Fine-grained lake sediments deposited in Glacial-age Lake Agassiz provide the rich soils of today that are the basis for agricultural food production, with approximately 70 percent of the land cover in agricultural uses. Wetlands and forested areas exist primarily in the eastern portions of the watershed. Watershed soils and geology vary from west to east across the watershed, in part largely because of the sediment deposition within Glacial-age Lake Agassiz and erosion of its former beach ridge areas.

The area’s extreme continental climate can experience wide annual temperature fluctuations and is semi- arid, with the watershed receiving an average of approximately 22 inches of precipitation per year. Combined with annual evaporation of approximately 30 inches, dry periods can result in very low stream flows along with increased irrigational needs and wildfire potential. The highest monthly rainfalls occur in May through September; June has the highest monthly rainfall. Based on the last 30 years of climate data for Argyle, Minnesota, the average number of days between spring and fall frosts is approximately 130 days with no increasing or decreasing pattern evident.

Continuous stream flows are being measured at three gages along the Snake River and one long-term, continuous gage on the Middle River, with data dating back to 1945. However, flows are not monitored below the confluence of the Snake and Middle Rivers, likely because of backwatering effects from the Red River of the North. Hence, monitored flows from the continuous gaging sites of the Middle and upper Snake Rivers were used to predict (via modeling) flows from the combined flow network. Considerable seasonal flow variability was noted, for example, with Middle River values ranging from peak spring flows (maximum of 3,500 cubic feet per second [cfs]) to very low- or no-flow conditions typically encountered in late summer and into the fall. These dry periods with very low base flows are a concern for aquatic biota as well as agricultural production.

Degraded water quality (sufficient to violate state water quality standards) was identified by the Minnesota Pollution Control Agency (MPCA) for six stream segments within the Snake River Watershed

RESPEC RSI-2483 i Snake River Watershed Conditions Report and encompassed the entire length of both the Snake River (five segments) and Middle River (one segment). The causes of impaired water quality for each stream segment vary and include low dissolved oxygen and excessive turbidity on the Middle River and the two most downstream reaches on the Snake River, impaired biota (fisheries) and low dissolved oxygen on Snake River’s third reach, impaired biota (fisheries) and turbidity on the Snake River’s fourth reach, and low dissolved oxygen on the Snake River’s headwater reach. Note that the MPCA has recently promulgated new eutrophication standards and replaced turbidity with total suspended solids (TSS) standards for rivers and streams that were approved by the U.S. Environmental Protection Agency (U.S. EPA) in late January 2015. These standards changes are expected to impact the 2015 stream assessment that will determine impairment listings within Snake River Watershed, which are currently being conducted by MPCA’s professional judgment team.

Water quality data were available from 21 monitoring sites located throughout the watershed, although the availability of various parameters varied greatly (e.g., many more stations had temperature data available than phosphorus or chlorophyll a data). Water quality evaluations of dissolved oxygen, turbidity, and TSS conducted by this study reinforced impairment listings previously identified. These evaluations also defined levels of E. coli, pH, and phosphorus that likely violate existing or newly approved river quality standards. The MPCA is currently evaluating the intensive monitoring data from 2012–2014, and updated water quality and biological assessments are expected in early 2015.

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TABLE OF CONTENTS

1.0 INTRODUCTION ...... 1 2.0 WATERSHED SETTING ...... 2 2.1 WATER RESOURCES ...... 2 2.1.1 Major Rivers and Streams...... 2 2.1.2 Lakes and Impoundments ...... 6 2.1.3 Wetlands ...... 6 2.1.4 Groundwater ...... 6 2.2 LAND CHARACTERISTICS ...... 7 2.2.1 Topography ...... 7 2.2.2 Geology and Geomorphology ...... 7 2.2.3 Soils ...... 10 2.2.4 Ecoregions ...... 10 2.2.5 Natural Resources ...... 10 2.3 CLIMATE ...... 14 2.4 HUMAN INFLUENCES...... 19 2.4.1 Land Use ...... 19 2.4.2 Water Use ...... 21 2.4.3 Drainage Systems ...... 21 2.4.4 Drinking Water Source Protection ...... 26 2.4.5 National Pollutant Discharge Elimination System Permitted Discharge Facilities ...... 26 2.4.6 Socioeconomics ...... 28 2.4.7 Local Governments ...... 30 2.4.7.1 Watershed Districts ...... 30 2.4.7.2 County Soil and Water Conservation Districts...... 30 3.0 WATER QUALITY STANDARDS AND IMPAIRMENTS ...... 31 3.1 WATER QUALITY STANDARDS ...... 31 3.1.1 Aquatic Life Protection Standards ...... 32 3.1.2 Aquatic Recreation Protection Standards ...... 33 3.2 IMPAIRMENTS ...... 34 4.0 EXISTING DATA AND PREVIOUS WORK...... 38 4.1 AVAILABILITY OF DATA ...... 38 4.1.1 Flow Data ...... 38 4.1.2 Water Quality Data ...... 40 4.2 OTHER APPLICABLE STUDIES ...... 40 4.2.1 Hydrologic and Hydraulic Models ...... 40 4.2.2 Water Quality Modeling ...... 45

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TABLE OF CONTENTS (Continued)

5.0 WATER QUALITY ANALYSIS ...... 46 5.1 FLOW ANALYSIS ...... 46 5.2 AQUATIC LIFE—PARAMETERS WITH TOXICITY-BASED STANDARDS ...... 49 5.3 AQUATIC LIFE—CONVENTIONAL PARAMETERS ...... 51 5.3.1 Dissolved Oxygen ...... 51 5.3.2 Temperature ...... 53 5.3.3 pH ...... 53 5.3.4 Turbidity ...... 53 5.3.5 Total Suspended Solids ...... 58 5.4 AQUATIC LIFE—BIOLOGICAL INDICATORS ...... 58 5.5 AQUATIC RECREATION—E. COLI BACTERIA ...... 63 5.6 AQUATIC RECREATION—EUTROPHICATION PARAMETERS ...... 63 6.0 CONCLUSIONS ...... 69 7.0 REFERENCES ...... 70 APPENDIX A: SOCIOECONOMIC DATA ...... A-1 APPENDIX B: ADDITIONAL FLOW ANALYSIS FIGURES...... B-1 APPENDIX C: ADDITIONAL WATER QUALITY ANALYSIS FIGURES ...... C-2 C.1 ASSESSMENT PERIOD ...... C-2 C.1.1 Additional Nutrient Species ...... C-2 C.1.2 Fecal Coliform ...... C-2 C.2 ENTIRE PERIOD OF RECORD ...... C-2 C.2.1 Report Figures ...... C-2 C.2.2 Trace Metals ...... C-2 C.2.3 Other Constituents ...... C-30

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LIST OF TABLES

TABLE PAGE

2-1 Snake River Watershed Impoundments (Flood Control) ...... 6 2-2 Threatened and Endangered Species ...... 15 2-3 PDS-Based Precipitation Frequency Estimates with 90 Percent Confidence Intervals ...... 20 2-4 Comparison of Atlas 14 to TP-40 for 24-Hour Storm Events...... 21 3-1 Applicable Toxicity-Based Water Quality Standards ...... 32 3-2 Numeric Criteria for Conventional Pollutants or Water Quality Characteristics ...... 32 3-3 Water Quality Standards for E. Coli Bacteria ...... 33 3-4 Applicable Stream Eutrophication Water Quality Standards for South River Nutrient Region 34 3-5 Impaired Waters Within the Snake River Watershed ...... 37 4-1 Availability of Discharge Data Within the Snake River Watershed ...... 38 4-2 Availability of Water Quality Data Within the Snake River Watershed ...... 42 4-3 Previous Studies Applicable to the Snake River Watershed ...... 43 5-1 Summary Statistics for Each Discharge Gage ...... 48 5-2 Minnesota Department of Natural Resources Index of Biological Integrity Scores...... 63 A-1 2012 Census Estimates ...... A-2

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LIST OF FIGURES

FIGURE PAGE

2-1 Location Map ...... 3 2-2 Water Resources ...... 4 2-3 Wetlands ...... 5 2-4 Groundwater Recharge ...... 8 2-5 Bedrock Geology ...... 9 2-6 Geomorphology ...... 11 2-7 Hydrologic Soil Groups ...... 12 2-8 Ecological Provinces and Land-Type Associations of the Snake River Watershed ...... 13 2-9 Minnesota Department of Natural Resources Wildlife Management Areas ...... 15 2-10 Monthly Climate Normals for Argyle, Minnesota ...... 17 2-11 Annual Precipitation and Snowfall Amounts for Argyle, Minnesota ...... 17 2-12 Average Annual Temperatures (Minimum, Maximum, and Overall Means) for Argyle, Minnesota ...... 18 2-13 Growing Season Length (Days) Based on Last Freeze of Spring to First Freeze of Fall for Argyle, Minnesota ...... 18 2-14 2006 National Land Cover Dataset ...... 22 2-15 2013 Cropland Data ...... 23 2-16 Water-Use Permitted Locations ...... 24 2-17 Drainage Systems ...... 25 2-18 Groundwater Susceptibility and Wellhead Protection Areas ...... 27 2-19 National Pollutant Discharge Elimination System-Permitted Discharge Facilities ...... 29 3-1 Minnesota Nutrient Regions ...... 35 3-2 Impaired Waters ...... 36 4-1 Discharge Gage Locations ...... 39 4-2 Water Quality Monitoring Locations ...... 41 5-1 Discharge Time Series ...... 47 5-2 Flow-Duration Curves ...... 49 5-3 Chloride Boxplots and Summary Statistics ...... 50 5-4 Total Ammonia Boxplots and Summary Statistics ...... 52 5-5 Dissolved Oxygen Boxplots and Summary Statistics ...... 54 5-6 Temperature Boxplots and Summary Statistics ...... 55 5-7 pH Boxplots and Summary Statistics ...... 56

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LIST OF FIGURES (Continued)

FIGURE PAGE

5-8 Turbidity Unit Regression ...... 57 5-9 Turbidity Boxplots and Summary Statistics ...... 59 5-10 Transparency Boxplots and Summary Statistics ...... 60 5-11 Total Suspended Solids Boxplots and Summary Statistics ...... 61 5-12 Minnesota Department of Natural Resources Assessment Locations ...... 62 5-13 E. coli Bacteria Boxplots and Summary Statistics ...... 64 5-14 Chlorophyll a Boxplots and Summary Statistics ...... 66 5-15 Biochemical Oxygen Demand Boxplots and Summary Statistics ...... 67 5-16 Total Phosphorus Boxplots and Summary Statistics ...... 68 B-1 Monthly Box-Whisker Plots for Minnesota Department of Natural Resources Discharge Gage 68032002 ...... B-2 B-2 Monthly Box-Whisker Plots for Minnesota Department of Natural Resources Discharge Gage 68031002 ...... B-3 B-3 Monthly Box-Whisker Plots for Minnesota Department of Natural Resources Discharge Gage 68006001 ...... B-4 B-4 Monthly Box-Whisker Plots for Minnesota Department of Natural Resources Discharge Gage 68017001 ...... B-5 C-1 Orthophosphate for Upstream to Downstream Sites...... C-3 C-2 Inorganic Nitrogen for Upstream to Downstream Sites ...... C-4 C-3 Nitrate for Upstream to Downstream Sites ...... C-5 C-4 Total Kjeldahl Nitrogen for Upstream to Downstream Sites ...... C-6 C-5 Fecal Coliform for Upstream to Downstream Sites ...... C-7 C-6 Chloride for Upstream to Downstream Sites ...... C-8 C-7 Ammonia for Upstream to Downstream Sites ...... C-9 C-8 Dissolved Oxygen for Upstream to Downstream Sites ...... C-10 C-9 Temperature for Upstream to Downstream Sites ...... C-11 C-10 pH for Upstream to Downstream Sites ...... C-12 C-11 Turbidity for Upstream to Downstream Sites ...... C-13 C-12 Transparency for Upstream to Downstream Sites ...... C-14 C-13 Total Suspended Solids for Upstream to Downstream Sites ...... C-15 C-14 E. coli for Upstream to Downstream Sites ...... C-16 C-15 Chlorophyll a for Upstream to Downstream Sites ...... C-17 C-16 Biochemical Oxygen Demand for Upstream to Downstream Sites ...... C-18

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LIST OF FIGURES (Continued)

FIGURE PAGE

C-17 Total Phosphorus for Upstream to Downstream Sites ...... C-19 C-18 Aluminum for Upstream to Downstream Sites ...... C-20 C-19 Arsenic for Upstream to Downstream Sites ...... C-21 C-20 Cadmium for Upstream to Downstream Sites ...... C-22 C-21 Chromium for Upstream to Downstream Sites ...... C-23 C-22 Copper for Upstream to Downstream Sites ...... C-24 C-23 Lead for Upstream to Downstream Sites ...... C-25 C-24 Mercury for Upstream to Downstream Sites ...... C-26 C-25 Nickel for Upstream to Downstream Sites ...... C-27 C-26 Selenium for Upstream to Downstream Sites ...... C-28 C-27 Silver for Upstream to Downstream Sites ...... C-29 C-28 Zinc for Upstream to Downstream Sites ...... C-30 C-29 Total Phosphorus for Upstream to Downstream Sites ...... C-31 C-30 Organic Carbon for Upstream to Downstream Sites ...... C-33 C-31 Total Sulfate for Upstream to Downstream Sites ...... C-34 C-32 Total Coliform for Upstream to Downstream Sites ...... C-36 C-33 Total Dissolved Solids for Upstream to Downstream Sites ...... C-37

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1.01.0 INTRODUCTION

The Snake River Watershed Restoration and Protection Strategy (WRAPS) is currently under development by the Middle-Snake-Tamarac Rivers Watershed District (MSTRWD) and the Minnesota Pollution Control Agency (MPCA). WRAPSs are a primary component of the MPCA’s comprehensive watershed approach to restoring and protecting water quality in Minnesota’s rivers, lakes, and wetlands. The watershed approach is a four-step process repeated on a 10-year cycle that includes (1) intensive monitoring, (2) data assessment, (3) developing a restoration and protection strategy, and (4) implementing restoration and protection projects. Essentially, the goal of the Snake River WRAPS is to develop strategies to protect waters where conditions meet water quality standards and to restore waters that are impaired.

The first task of the Snake River WRAPS is developing a Watershed Conditions Report that provides an overview of the water resources within the watershed and characterizes the current water quality conditions. The goal of the report is to summarize existing data and studies to identify trends in water quality, potential stressors to the biological integrity of the waterbodies, potential pollutant sources, and information gaps. This report contains seven chapters and three appendices. Chapter 2.0 describes the watershed setting and is organized to depict the water, land, natural resources, anthropogenic influences, and socioeconomics. The applicable water quality standards and 303(d)-listed (impaired) waters within the watershed are reviewed in Chapter 3.0, and a summary of the available water-quantity and water quality data is given in Chapter 4.0. Chapter 5.0 contains an analysis of the available data that summarizes the existing water quality conditions within the Snake River Watershed. The conclusions are provided in Chapter 6.0, and cited references are provided in Chapter 7.0. The report concludes with appendices that contain socioeconomic data, additional flow analysis figures, and additional water quality analysis figures.

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22..00 WATERSHED SETTING

The Snake River Watershed (Hydrologic Unit Code [HUC] 09020309) drains an area of 611,800 acres (or 956 square miles) in northwestern Minnesota, as shown in Figure 2-1. The majority of the watershed is located in Marshall County, with smaller portions located in Polk and Pennington Counties. The Snake River Watershed is bordered on the west by the Red River, to the north by the Lower Red River Watershed, to the east by the Thief River, and to the south by Grand Marias Creek. Municipalities located in the watershed include Argyle, Alvarado, Warren, Viking, Newfolden, Holt, and Middle River. The Snake River Watershed is managed by the MSTRWD, which is located in Warren, Minnesota.

The northern portion of the flow network (the Middle River) begins in east-central Marshall County at an elevation of approximately 1,237 feet above mean sea level (AMSL) with a slightly lower headwater elevation of approximately 1,072 feet AMSL for the Snake River. Hence, there is an elevational loss of approximately 467 feet along the Middle River (approximately 5 feet per river mile), while the Snake River drops approximately 300 feet to its outlet at the Red River of the North (770 feet AMSL) for a drop of approximately 3 feet per river mile. The combined flows of the Snake River discharge into the Red River of the North near River Mile Index (RMI) 230. The boundaries of the U.S. Geological Survey (USGS) 8-digit HUC and the boundaries of the MSTRWD are illustrated in Figure 2-1.

2.1 WATER RESOURCES

The water resources of the Snake River Watershed are predominantly agriculturally based and developed to provide drainage and flood reduction for agricultural fields. As shown in Figure 2-2, major surface water resources include the Snake River along the southern and western boundaries; its tributaries and an extensive drainage network in the glacial-lake area; and the Middle River, which flows along the northern boundary of the watershed. The various water resources of the Snake River Watershed, including major rivers and streams, lakes and impoundments, wetlands, and groundwater, are discussed in the following text and illustrated in Figures 2-2 and 2-3.

2.1.1 Major Rivers and Streams

The Snake River Watershed contains three major rivers, including the Middle River, the South Branch Snake River, and the Snake River. The USGS National Hydrology Dataset (NHD) has identified 88, 20, and 85 miles of natural channel in the Middle River, South Branch Snake River, and Snake River, respectively [USGS, 2012]. The Middle River is located in the northern region of the watershed, originates in the northeast corner (approximately 7 miles southeast of the town of Middle River), and flows west through the towns of Newfolden and Argyle before it is channelized approximately 4 miles before its confluence with the Snake River. The South Branch Snake River begins in the southeastern portion of the watershed, near the town of Viking, and flows generally west until it joins the Snake River approximately 6 miles west of Warren, Minnesota. The Snake River originates in the east-central portion of the watershed (approximately 6 miles west of the town of Newfolden) and flows southwest to its confluence with its South Branch. It then flows west through the city of Alvarado before turning north to continue to pick up the Middle River and ultimately outlet to the Red River of the North. The watershed also contains an extensive drainage system, which is described further in Section 2.4.3. The streams and rivers in the Snake River Watershed are depicted in Figure 2-2.

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3 Figure 2-1. Location of the Snake River Watershed and Middle-Snake-Tamarac Rivers Watershed District Boundary.

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4 Figure 2-2. Water Resources of the Snake River Watershed.

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5 Figure 2-3. Wetlands of the Snake River Watershed.

Snake River Watershed Conditions Report

2.1.2 Lakes and Impoundments

This portion of the state has few natural lakes. The Minnesota Department of Natural Resources (MN DNR) has identified six lakes within the watershed, ranging in size from 1.4 acres to 1,400.6 acres. The Florian Marsh is the only named waterbody [MN DNR, 2008]. Two major impoundment structures are located within the watershed, including the Agassiz Valley Water Resource Management Project (Agassiz Valley) and PL-566 Off Channel Flood Water Storage Site, and one diversion, the Richard P. Nelson Memorial Floodway. The primary purpose of these impoundments is for flood-control storage; however, they also provide habitat, water for irrigation, and base flow to ephemeral streams during the dry season [MSTRWD, 2011]. Storage characteristics for these impoundments are listed in Table 2-1. Also mentioned in the Marshall County Water Management Plan are Angus-Oslo #1 and #4 impoundments located in Polk County, which are used for flood control and storage.

Table 2-1. Snake River Watershed Impoundments (Flood Control)

Impoundment Storage

Agassiz Valley Water Resource Management 6,840 acre-feet, ungated is Project (McCrea Impoundment) 10,670 acre-feet

PL-566 Off Channel Floodwater Storage 6,700 acre-feet

Richard P. Nelson Memorial Floodway N/A

Angus-Oslo #1 10-year event, 340 acre-feet

Angus-Oslo #4 4,500 acre-feet

2.1.3 Wetlands

The majority of the wetland areas in the Snake River Watershed are found in the eastern and northeastern portions of the region, as shown in Figure 2-3. This is largely because the western portion has been extensively drained for agricultural purposes. According to the Minnesota Board of Water and Soil Resources (MN BWSR) Minnesota Wetland Program Plan, less than 50 percent of the prestatehood wetland area is remaining, which the MN DNR notes is approximately 10.62 million acres [Gernes, 2012]. Today, wetlands are managed and monitored by both the MN BWSR and MN DNR as well as local government units. Wetlands are characterized by areas of land with primarily hydric soils that are saturated by either ground or surface water for a time adequate to support hydrophilic vegetation and the predominance of this vegetation under typical conditions [MN DNR, 1997]. Figure 2-3 depicts the remaining wetland areas in the Snake River Watershed, which are primarily classified as Palustrine. These wetlands are freshwater systems that include shallow ponds, marshes, swamps, and sloughs [Cowardin et al., 1979].

2.1.4 Groundwater

The groundwater in the Snake River Watershed is defined by its geologic setting and history, which are described further in the following sections. Located in the lakebed of ancient Glacial Lake Agassiz, the watershed is characterized by primarily fine-grained, poorly drained soils. In the western portion of the watershed, near the Red River, these soils can be up to 100 feet thick and are underlain by Cretaceous marine sediments of the Glacial-Lake Plain that yield highly saline waters [Marshall County Water

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Resources Advisory Committee, 2012]. Further east, in the headwater regions of the Snake, South Branch Snake, and Middle Rivers, the soils and underlying geology transition to more coarse soils that include loams, sands, and gravels that are underlain by the Glacial-Lake Washed Till Plain, which are the ancient beach deposits of Lake Agassiz [Marshall County Water Resources Advisory Committee, 2012]. These areas provide surficial, unconfined, shallow aquifers as well as deeper, underlying confined aquifers [Marshall County Water Resources Advisory Committee, 2012]. Figure 2-4 illustrates groundwater recharge estimations derived by the MN DNR from observation well data [MN DNR, 2007].

2.2 LAND CHARACTERISTICS

The following sections describe the land characteristics of the Snake River Watershed, including its topography, geology and geomorphology, soils, ecoregions, and natural resources.

2.2.1 Topography

The Snake River Watershed is located within the Red River Valley, which was once at the bottom of Lake Agassiz. As the waters of this ancient lake receded, a large, flat expanse was left that is the signature feature of this area. Elevations range from 770 to 1,237 feet AMSL with much of the relief found in the watershed’s eastern region. The Snake River Watershed’s eastern half contains several wispy bands of rolling and undulating terrain, with a larger concentration of rolling terrain occurring just north of the easternmost tip of the watershed. This undulating terrain is known as the beach ridges and was formed as the Lake Agassiz water levels fluctuated through the years.

The MSTRWD plan divides the watershed into three generalized topographic regions: (1) the Lake Plain in the western half, with westward slopes of less than 8 feet per mile; (2) the Transitional Area, which is a thin transitional band with westward slopes of 8 to 20 feet per mile; (3) and the Upland Area in the east, with westward slopes of less than 10 feet per mile [MSTRWD, 2011]. Additionally, the prairie pothole region of Minnesota covers the entire Snake River Watershed. Before agriculture’s dominance in this region, the landscape consisted of native prairie grasslands interspersed with small depressional wetlands, as the prairie pothole name implies. This unique landscape has been mostly replaced or altered through drainage and conversion to cultivated cropland and urban development; the depressional areas, although no longer holding water year-round, are still recognizable features of the landscape [U.S. Fish and Wildlife Service, 2011].

2.2.2 Geology and Geomorphology

The bedrock geology of the Snake River Watershed is shown in Figure 2-5. In general, the eastern portion of the watershed is characterized by metamorphic and igneous rocks, while the watershed’s western region is characterized by sedimentary bedrock. The metamorphic and igneous rocks are found in pockets of post-algoman orogen intermediate multiphase intrusions across the northeastern portion of the watershed as well as much of the southeastern area, which consists of syntectonic to pretectonic granitoid rocks. The remainder of the watershed consists of stratified rocks, with much of the western third of the watershed consisting of Cretaceous rocks from the late-Mesozoic era and much of the remaining northeastern portion of the watershed being made up of metavolcanic rocks.

The geomorphology of the Snake River Watershed was shaped by the historic Glacial Lake Agassiz. Hydrologic processes of water entering and leaving this ancient lake account for the landform features

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8 Figure 2-4. Groundwater Recharge Estimates for the Snake River Watershed.

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9 Figure 2-5. Bedrock Geology of the Snake River Watershed.

Snake River Watershed Conditions Report seen across this watershed. Two geomorphic associations are found within this watershed, as shown in Figure 2-6—the Red River Lobe, which accounts for 60 square miles or approximately 8 percent of the watershed in the east, and Glacial Lake Agassiz, which accounts for the remaining 92 percent. The Red River Lobe bordered ancient Lake Agassiz and is composed of till plain sediment that is mostly fine-loamy soils. Lake Agassiz sediments consist of fertile lacustrine silt and clay across much of what was submerged by the lake. Lake Agassiz is bordered by beach ridges made up of sandy deposits and it left the large, flat landscape of the Red River Valley and provided the rich fertile soil that is a key factor in agricultural success in this region.

2.2.3 Soils

The soils in the Snake River Watershed vary from east to west, with much of the eastern areas consisting of sandy, loamy soils and the western third of the watershed consisting of fine, silty soils (Figure 2-7). The hydrologic soil group classifications show that soils with moderate to high runoff potential (C, D, and C/D) are concentrated in the western third of the watershed. Much of the middle third has moderately low runoff potential (A and B). The eastern third is dominated by dual hydrologic soil groups that have drained/undrained classifications mostly of A/D and B/D, where they will respond with lower runoff potential if soils are drained and high runoff potential if soils are not drained [Beck and Wright-Koll, 2000].

2.2.4 Ecoregions

Surface water resources of the United States have been organized by aquatic ecoregions that are relatively homogenous areas based on climate, landforms, soils, hydrology, and potential natural vegetation [Omernik, 1987]. The Snake River Watershed is located within the Lake Agassiz Plain (LAP) Level III ecoregion characterized by flat topography resulting from the deposition of lake sediments over thousands of years. Aquatic ecoregions have been used to distinguish Minnesota’s water quality patterns and were used in developing lake water quality standards. In a similar fashion, river eutrophication and total suspended solids (TSS) numeric water quality standards are based on grouped ecoregion areas referred to as northern, central, and southern river nutrient regions.

A slightly different classification scheme, referred to as ecological provinces, is also widely used to define land areas with similarities of climate, native vegetation, and biomes [MN DNR, 2015]. Figure 2-8 depicts the Prairie Parkland (western Snake River Watershed) and Tallgrass Aspen Parklands Provinces (eastern Snake River Watershed), including land-type association subclasses.The historic tallgrass native prairie has become a threatened resource because it has gradually been replaced by intensive row crop agriculture and development. The preferred crops in the northern half of the region are potatoes, beans, sugar beets, wheat, and soybeans. Corn is more common in the southern portion [U.S. Environmental Protection Agency, 2010].

2.2.5 Natural Resources

The Minnesota Biological Survey (MBS) has designated nearly 50 square miles within the Snake River Watershed as sites of significance for biodiversity. More than one-half of this area ranked as high or outstanding, all of which is within the Lake Agassiz Aspen Parklands ecological province. Additionally, the MBS Railroad Rights-of-Way Prairies include approximately 13 miles in the Snake River Watershed, and much of the rail line from Warren to Argyle ranked as good or very good and a few sections from Argyle to Stephen ranked as fair and very good.

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11 Figure 2-6. Geomorphology of the Snake River Watershed.

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12 Figure 2-7. Hydrologic Soil Groups of the Snake River Watershed.

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13 Figure 2-8. Ecological Provinces and Land-Type Associations of the Snake River Watershed.

Snake River Watershed Conditions Report

The Snake River Watershed contains 11 Wildlife Management Areas (WMAs): Adolf Elseth Memorial, Alvarado, Florian, Huntly, New Folden, New Maine, Red River of the North, Spruce Valley, Thief Lake, West Valley, and Wright. The WMAs are depicted in Figure 2-9. The majority of the land area in these WMAs aligns with the MBS areas and includes mostly forests and shrublands. Some of these areas are situated within 3 miles of the Agassiz National Wildlife Refuge, which is the second largest national wildlife refuge in the state of Minnesota. Agassiz National Wildlife Refuge provides a refuge and breeding ground for migratory birds and habitat for resident wildlife, such as sharp-tailed grouse, moose, deer, and wolves [U.S. Fish & Wildlife Service, 2000].

Wildlife habitat is also provided by the surface waters described in the previous section, including rivers and streams, lakes and impoundments, and wetland areas, particularly in the eastern portion of this watershed. Flood-control impoundments in the Snake River Watershed, such as the Agassiz Valley Water Resources Management, offer added value by supplementing base flow during the dry times later in the year as well as creating shallow pools that provide wildlife habitat and recreational value for the area [MSTRWD, 2009].

The National Resources Conversation Service (NRCS) has inventoried 26 endangered, threatened, and candidate species within the Snake River Watershed. Species of concern are listed in Table 2-2 [NRCS, 2012].

2.3 CLIMATE

This watershed lies in the northern Midwest, which has some of the most active weather systems in the world resulting from the clash of air masses from the Gulf of Mexico, the Pacific Ocean/Rocky Mountains, and Canada. The area has been described as having an extreme continental climate and are subject to temperature extremes as warm, humid summer conditions shift to extreme cold temperatures of the dormant seasons. The lack of proximity to major temperature-modifying geologic features, such as large lakes and mountains, contributes to these fluctuations.

Climate data for the past 30 years for Argyle, Minnesota, were retrieved from the Midwestern Regional Climate Center (MRCC) cli-MATE (http://mrcc.isws.illinois.edu/CLIMATE/) and summarized with long-term average values (normals) plotted in Figure 2-10. Peak rainfall occurs from May through September, with June typically experiencing the highest monthly totals (approximately 3.6 inches).

Annual precipitation and snowfall for Argyle, Minnesota, were 21.6 inches and 41.4 inches per year, respectively, with considerable year-to-year variation, as illustrated in Figure 2-11. The annual evaporation is approximately 30 inches, which resulted in a strong net water budget deficit gradient that varies from –2 to –10 inches per year moving from east to west across Marshall County [Farnsworth et al., 1982]. This annual water deficit is a concern to agricultural producers and can also create conditions favorable to wildfires during prolonged dry periods. Average annual maximum, minimum, and mean temperatures have fluctuated without substantial apparent increasing or decreasing patterns (Figure 2-12), while increasing annual minimum temperatures were noted for Grand Forks, North Dakota. The growing season lengths, defined as the number of days between the last freeze dates of spring and the first freeze dates of fall, were plotted for Argyle, Minnesota. No patterns of increases or decreases were noted over the past 30 years (Figure 2-13).

RESPEC RSI-2483 14

RESPEC RSI

RSI

2417

- RSI

- -

- 2483

009

001

Snake River Watershed Snake Conditions ReportRiver Watershed

15 Figure 2-9. Minnesota Department of Natural Resources Wildlife Management Areas.

Snake River Watershed Conditions Report

Table 2-2. Threatened and Endangered Species

Scientific Name Common Name Type

Ammodramus nelsoni Nelson’s Sharp-Tailed Sparrow Zoological Androsace septentrionalis ssp. puberulenta Northern Androsace Botanical Asio flammeus Short-Eared Owl Zoological Botrychium campestre Prairie Moonwort Botanical Botrychium simplex Least Moonwort Botanical Carex obtusata Blunt Sedge Botanical Carex scirpoidea Northern Singlespike Sedge Botanical Carex sterilis Sterile Sedge Botanical Carex xerantica Dry Sedge Botanical Coturnicops noveboracensis Yellow Rail Zoological Cypripedium candidum Small White Lady’s-Slipper Botanical Gentiana affinis Northern Gentian Botanical Helictotrichon hookeri Oat-Grass Botanical Limosa fedoa Marbled Godwit Zoological Microtus ochrogaster Prairie Vole Zoological Minuartia dawsonensis Rock Sandwort Botanical Mustela nivalis Least Weasel Zoological Orobanche ludoviciana Louisiana Broomrape Botanical Phalaropus tricolor Wilson’s Phalarope Zoological Rhynchospora capillacea Hair-Like Beak-Rush Botanical Salix maccalliana McCall’s Willow Botanical Senecio canus Gray Ragwort Botanical Silene drummondii Drummond’s Campion Botanical Stellaria longipes Long-Stalked Chickweed Botanical Thomomys talpoides Northern Pocket Gopher Zoological Tympanuchus cupido Greater Prairie-Chicken Zoological

RESPEC RSI-2483 16 Snake River Watershed Conditions Report

RSI-2417-14-010

Figure 2-10. Monthly Climate Normals for Argyle, Minnesota (USC00210252)

RSI-2417-14-011

Annual Precipitation and Snowfall for Argyle, MN (USC00210252)

80 Annual Precipitation (Inches) 70 Annual Snowfall (inches) 60

40 Inches 30

0 1985 1990 1995 2000 2005 2010

Figure 2-11. Annual Precipitation and Snowfall Amounts for Argyle, Minnesota.

RESPEC RSI-2483 17 Snake River Watershed Conditions Report

RSI-2417-14-012

Average Annual Temperatures (F) Minimum, Maximum & Mean Argyle, MN USC 00210252 60

30 Degrees F 20

10 Maximum Mean Minumum

0 1985 1990 1995 2000 2005 2010

Figure 2-12. Average Annual Temperatures (Minimum, Maximum, and Overall Means) for Argyle, Minnesota.

RSI-2417-14-013

Growing Season Length based on 32 Degree F (Last of Spring to First of Fall) Argyle, MN USC00210252 170 160 150 140

130

Days 120 110 100 90 80 1985 1990 1995 2000 2005 2010 2015

Figure 2-13. Growing Season Length (Days) Based on Last Freeze of Spring to First Freeze of Fall for Argyle, Minnesota.

RESPEC RSI-2483 18 Snake River Watershed Conditions Report

Recently, the National Oceanic and Atmospheric Administration (NOAA) completed updating the precipitation intensities and durations for 11 Midwest states, including Minnesota. From these records, summary information for Argyle, Minnesota, was tabulated and presented in Table 2-3. The average reoccurrence intervals (annually to every 1,000 years) are shown across the horizontal rows in Table 2-3 and the storm/wet period durations (5 minutes to 60 days) are noted along the vertical column. The 24-hour storms (highlighted in light red) typically described in daily weather forecasts range from the common storm (once per year statistically) of approximately 1.9 inches to 8.8 inches for the once-per- 1,000-year storms. The 100-year storm per 24 hours was estimated to be 5.87 inches.

Different storm recurrence levels are used for design purposes. For example, urban stormwater management typically focuses on the 2-year storms for water quality purposes (e.g., 2.3 inches per 24 hours), highway designs focus more on the 10-year storms (e.g., 3.52 inches per 24 hours), and urban flooding focuses on the 100-year events (e.g., 5.87 inches per 24 hours). Of particular note to agricultural designs are the intense 30-minute storms (ranging from 0.79 inch [annually] to 3.1 inches [every 1,000 years]) and wet periods. Back-to-back storms or wet periods are highlighted in yellow in Table 2-3, with annual values ranging from approximately 2.2 inches to 3.4 inches annually to approximately 3.9 inches to 5.4 inches occurring every 10 years. The wet period precipitation totals often generate significant runoff; in the Red River of the North Basin, this has been referred to as nonlinear runoff responses. Therefore, the 2- to 10-day wet period rainfall totals may be of utility when considering watershed storage and treatment designs.

The most recent Atlas 14 precipitation analyses replace the older version referred to as TP-40, which was published in 1961 and based on rainfall records from the 1930s to the late 1950s. Based on the updated data, 24-hour storm events have increased for 2- to 100-year recurrence periods, as noted in Table 2-4. These increased rainfall amounts are some of the largest increases noted in Minnesota.

2.4 HUMAN INFLUENCES

Anthropogenic influences within the Snake River Watershed, including land use, water use and protection, drainage systems, permitted discharge facilities, socioeconomics, and local governments, are discussed in the following sections.

2.4.1 Land Use

Land cover was assessed by using the 2011 National Land Cover Dataset (NLCD) and is illustrated in Figure 2-14. Based on the NLCD, the major land use in the Snake River Watershed is cultivated crops (78.44 percent). The next largest group is wetlands (7.29 percent), followed by forests (5.58 percent), developed areas (5.03 percent), and pasture (2.98 percent). Small areas of open water, shrub/scrub, and grassland (each greater than 1 percent) also exist. The developed areas are attributed to municipalities and roadways.

Because so much of the watershed is dedicated to agricultural use, land cover was also evaluated by using the 2013 Cropland Data Layer (CDL). Spatial distribution of crop diversity is shown in Figure 2-15. Land cover percentages differ slightly from what was seen in the 2011 NLCD. Primary crops in 2006, as identified by the CDL, include soybeans (25.86 percent), spring wheat (18.37 percent), and corn (6.88 percent).

RESPEC RSI-2483 19

RESPEC Table 2-3. PDS-Based Precipitation Frequency Estimates with 90 Percent Confidence Intervals

RSI

- Average Recurrence Interval (Years) 2417

RSI Duration

1 2 5 10 25 50 100 200 500 1000

- - 2483 0.33 0.389 0.49 0.577 0.703 0.804 0.909 1.02 1.17 1.29 14

5-min -

001 (0.254-0.429) (0.299-0.507) (0.375-0.639) (0.439-0.756) (0.521-0.954) (0.582-1.10) (0.637-1.28) (0.688-1.47) (0.762-1.73) (0.818-1.93)

0.483 0.57 0.717 0.845 1.03 1.18 1.33 1.49 1.72 1.89 10-min (0.372-0.629) (0.438-0.742) (0.549-0.936) (0.644-1.11) (0.762-1.40) (0.852-1.62) (0.933-1.87) (1.01-2.15) (1.11-2.53) (1.20-2.82) 0.59 0.695 0.875 1.03 1.25 1.44 1.62 1.82 2.09 2.31 15-min (0.453-0.767) (0.534-0.905) (0.670-1.14) (0.785-1.35) (0.930-1.70) (1.04-1.97) (1.14-2.28) (1.23-2.62) (1.36-3.09) (1.46-3.44) 0.788 0.932 1.18 1.39 1.69 1.93 2.18 2.44 2.81 3.09 30-min (0.606-1.02) (0.716-1.21) (0.901-1.53) (1.06-1.82) (1.25-2.29) (1.40-2.65) (1.53-3.06) (1.65-3.52) (1.82-4.14) (1.95-4.61) 0.978 1.16 1.48 1.75 2.15 2.47 2.81 3.16 3.65 4.04 60-min (0.752-1.27) (0.892-1.51) (1.13-1.93) (1.33-2.29) (1.59-2.92) (1.79-3.40) (1.97-3.94) (2.13-4.55) (2.37-5.39) (2.56-6.03) 1.17 1.39 1.78 2.11 2.61 3.01 3.43 3.88 4.5 5 2-hr (0.910-1.50) (1.08-1.79) (1.38-2.29) (1.63-2.73) (1.96-3.50) (2.21-4.09) (2.43-4.77) (2.65-5.52) (2.96-6.57) (3.19-7.37) 1.28 1.52 1.96 2.34 2.9 3.36 3.85 4.37 5.1 5.69 3-hr (1.00-1.63) (1.19-1.94) (1.53-2.50) (1.81-3.00) (2.19-3.88) (2.48-4.54) (2.75-5.32) (3.00-6.19) (3.38-7.41) (3.66-8.33) 1.48 1.77 2.27 2.73 3.41 3.97 4.57 5.21 6.11 6.84 6-hr (1.17-1.86) (1.40-2.22) (1.80-2.87) (2.15-3.46) (2.61-4.51) (2.97-5.30) (3.30-6.24) (3.62-7.30) (4.09-8.78) (4.45-9.90) 1.71 2.03 2.61 3.13 3.91 4.56 5.25 5.98 7.03 7.87 12-hr (1.37-2.12) (1.63-2.52) (2.09-3.25) (2.49-3.92) (3.04-5.11) (3.45-6.01) (3.84-7.08) (4.21-8.29) (4.75-9.98) (5.17-11.3) 1.94 2.3 2.94 3.52 4.38 5.1 5.87 6.7 7.87 8.81 24-hr (1.58-2.38) (1.87-2.82) (2.38-3.61) (2.83-4.34) (3.45-5.65) (3.91-6.65) (4.35-7.83) (4.76-9.17) (5.38-11.0) (5.85-12.5) 2.19 2.58 3.26 3.89 4.82 5.61 6.45 7.36 8.65 9.69 2-day (1.81-2.64) (2.12-3.11) (2.68-3.95) (3.17-4.72) (3.84-6.15) (4.35-7.22) (4.84-8.50) (5.29-9.95) (5.98-12.0) (6.50-13.6) 2.37 2.77 3.5 4.15 5.12 5.93 6.79 7.72 9.04 10.1 3-day

(1.97-2.83) (2.30-3.33) (2.89-4.20) (3.41-5.00) (4.11-6.46) (4.63-7.56) (5.13-8.87) (5.59-10.4) (6.29-12.4) (6.82-14.0) 2.53 2.96 3.7 4.36 5.34 6.16 7.03 7.96 9.27 10.3 Snake Conditions ReportRiver Watershed 4-day (2.12-3.02) (2.46-3.52) (3.07-4.41) (3.60-5.23) (4.30-6.70) (4.84-7.81) (5.33-9.12) (5.79-10.6) (6.48-12.7) (7.00-14.3) 3 3.44 4.21 4.88 5.87 6.68 7.54 8.45 9.73 10.7 7-day (2.54-3.54) (2.90-4.05) (3.53-4.96) (4.08-5.79) (4.77-7.25) (5.29-8.36) (5.77-9.66) (6.20-11.1) (6.86-13.2) (7.35-14.7) 3.42 3.88 4.69 5.39 6.41 7.24 8.1 9.02 10.3 11.3 10-day (2.90-3.99) (3.30-4.54) (3.97-5.49) (4.53-6.34) (5.23-7.84) (5.76-8.97) (6.23-10.3) (6.65-11.8) (7.28-13.8) (7.77-15.3) 4.54 5.16 6.18 7.04 8.24 9.18 10.1 11.1 12.4 13.4 20-day (3.91-5.22) (4.44-5.94) (5.30-7.14) (6.00-8.17) (6.79-9.87) (7.38-11.2) (7.87-12.6) (8.27-14.3) (8.88-16.4) (9.35-18.0) 5.49 6.24 7.46 8.45 9.8 10.8 11.8 12.9 14.2 15.2 30-day (4.77-6.27) (5.41-7.13) (6.44-8.54) (7.26-9.72) (8.12-11.6) (8.76-13.0) (9.25-14.6) (9.62-16.3) (10.2-18.5) (10.6-20.2) 6.75 7.65 9.08 10.2 11.7 12.8 13.9 14.9 16.2 17.1 45-day (5.90-7.63) (6.69-8.66) (7.91-10.3) (8.85-11.7) (9.75-13.7) (10.4-15.2) (10.9-16.9) (11.2-18.7) (11.7-20.9) (12.0-22.6) 7.85 8.88 10.5 11.7 13.3 14.4 15.5 16.5 17.6 18.4 60-day (6.91-8.83) (7.81-9.99) (9.17-11.8) (10.2-13.3) (11.1-15.4) (11.8-17.0) (12.2-18.7) (12.4-20.5) (12.8-22.6) (13.0-24.2)

Snake River Watershed Conditions Report

Table 2-4. Comparison of TP-40 to Atlas 14 for 24-Hour Storm Events

RSI

- Recurrence TP-40 Atlas 14 2417 Percent

Interval Precipitation Precipitation - Change 14 (years) (inches) (inches)

001

2 6 2.18 2.3 5 2 2.89 2.94 10 3 3.41 3.52 25 8 4.07 4.38 50 11 4.58 5.1 100 15 5.1 5.87 1,000 – – 8.81

2.4.2 Water Use

Water use in the Snake River Watershed is comprised of two primary categories: rural water districts and municipal waterworks. Additionally, Minnesota Statute 103G.265 requires the MN DNR to manage water resources to ensure an adequate supply to meet long-range seasonal requirements for domestic, agricultural, fish and wildlife, recreational, power, navigation, and quality control purposes. Water Appropriation Permits are required by the MN DNR when groundwater withdrawal exceeds 10,000 gallons per day (gpd) or 1 million gallons per year (mgpy). The Snake River Watershed has several active MN DNR Water Appropriation Permits, most of which are for municipalities or rural water districts. Municipalities with permits include Warren, Alvarado, Viking, Grygla, Newfolden, Argyle, Middle River, and Strandquist. Rural water districts include Marshall and Polk Counties Rural Water District, and the permitted withdrawal volumes and rates range from 144,000–864,000 gpd and 3–110 mgpy, respectively [MN DNR, 2014]. Other permitted appropriations include groundwater withdrawal permits for landscape and crop irrigation and surface water permits for mine dewatering and water-level maintenance. Figure 2–16 depicts the water appropriation permit locations.

2.4.3 Drainage Systems

Agricultural and urban areas in the Snake River Watershed are intensively drained by artificial drainage systems (as largely defined by Minnesota Drainage Code [Minnesota Statute 103E]). This statute defines a drainage system as “…a system of ditch or tile, or both, to drain property, including laterals, improvements, and improvements of outlets, established and constructed by a drainage authority.” Also defined by the statute, “’drainage system’ includes the improvement of a natural waterway used in the construction of a drainage system and any part of a flood-control plan proposed by the United States or its agencies in the drainage system.” Drainage authorities are boards or a joint county drainage authority having jurisdiction over a drainage system as determined by county boards or district courts. In the urban setting, artificial drainage is commonly referred to as curbs and gutters discharging to storm sewers and ditches. In the agricultural setting, artificial drainage may consist of open ditches, closed ditches, public tile mains, and private tile components. County, judicial, and state ditches are located in the Snake River Watershed and identified in Figure 2-17. These systems serve to connect poorly drained agricultural lands to the natural drainage network of creeks, streams, and rivers that convey water to the Red River.

RESPEC RSI-2483 21

RESPEC RSI

RSI

2417

- RSI

- -

- 2483

014

001

Snake River Watershed Snake Conditions ReportRiver Watershed

22 Figure 2-14. 2011 National Land Cover Dataset.

RESPEC RSI

RSI

2417

- RSI

- -

- 2483

015

001

Snake River Watershed Snake Conditions ReportRiver Watershed

23 Figure 2-15. 2013 Cropland Data Layer.

RESPEC RSI

RSI

2417

- RSI

- -

- 2483

016

001

Snake River Watershed Snake Conditions ReportRiver Watershed

24 Figure 2-16. Water-Use Permitted Locations.

RESPEC RSI

RSI

2417

- RSI

- -

- 2483

017

001

Snake River Watershed Snake Conditions ReportRiver Watershed

25 Figure 2-17. Drainage Systems Within the Snake River Watershed.

Snake River Watershed Conditions Report

In general, drainage systems can comprise open ditches, closed ditches, public tile mains, and private tile components. The importance of channelized (open) ditches within the Snake River Watershed is shown in Figure 2-17. Historically, wet areas—wetlands, seasonally ponded areas, and areas with high groundwater levels—were converted to areas suitable for intensive row crop agriculture with the introduction of affordable subsurface drainage tile. Further crop yield benefits have been seen in areas that were historically farmed, such as fewer instances of seasonally saturated and soil-limiting spring planting and less crop stress because of high soil moisture in the root zone.

Drainage systems may be managed by watershed districts, cities, counties, or multiple counties, as determined by county boards or district court. Minnesota Statute 103E governs public drainage systems and their operation in Minnesota. The Middle-Snake-Tamarac Rivers Watershed has approximately 750 miles of public drainage systems, of which 329 miles are administered by the MSTRWD. State ditches and judicial ditches (those involving more than one county) were transferred to MSTRWD beginning in 1973. Over the past 4 decades, several county systems have also been transferred to MSTRWD control. Additionally, new drainage systems (including county ditch systems) and improved systems are required to be transferred to watershed districts. The MSTRWD currently administers 26 drainage systems [MSTRWD, 2013].

2.4.4 Drinking Water Source Protection

The 1996 amendments to the federal Safe Drinking Water Act require states to have wellhead protection programs in place to prevent contamination of public water supplies [Minnesota Department of Health, 2013a]. The Minnesota Department of Health administers the state’s Wellhead Protection Program, which currently protects groundwater resources. The program was recently expanded to a full Source Water Protection Program, which will include protecting surface water as well as groundwater supplies [Minnesota Department of Health, 2013b]. Wellhead protection areas within the Snake River Watershed have been designated for the municipalities of Argyle and Viking, as well as for Marshall-Polk Counties’ Rural Water System 6 and Rural Water System East. Figure 2-18 illustrates the areas within the watershed that, based on recharge patterns, are susceptible to groundwater contamination, as well as the wellhead protection areas designated to protect municipal and rural water supplies.

The Minnesota Department of Agriculture (MDA) is the lead state agency for all aspects of pesticide and fertilizer environmental and regulatory functions. These authorities are described in Minnesota Statutes 18B, 18C, 18D, and 103H. The MDA has an established groundwater monitoring program of public and homeowner wells that is being used to analyze for sensitivity to pesticides and fertilizers. Nitrate nitrogen concentrations in groundwater is a primary fertilizer component that is being assessed.

2.4.5 National Pollutant Discharge Elimination System Permitted Discharge Facilities

The Snake River Watershed contains several National Pollutant Discharge Elimination System- (NPDES-) permitted discharge facilities, as illustrated in Table 2-5 and Figure 2-19. Most of these point-source dischargers are Wastewater Treatment Plants (WWTPs) located in municipalities throughout the watershed. These include the Argyle, Alvarado, Warren, Viking, Newfolden, and Middle River WWTPs. One industrial permit is listed for Hawkes Co Inc. All of these are considered minor discharges. Four other NPDES permits are located in the watershed, but these facilities do not discharge. Figure 2-19 shows discharging NPDES permit locations in the Snake River Watershed.

RESPEC RSI-2483 26

RESPEC RSI

2417

- RSI

- -

- 2483

018

001

Snake River Watershed Snake Conditions ReportRiver Watershed

27 Figure 2-18. Groundwater Susceptibility and Wellhead Protection Areas Within the Snake River Watershed.

Snake River Watershed Conditions Report

Table 2-5. National Pollutant Discharge Elimination System-Permitted Facilities Within the Snake River Watershed

Name Site I.D.

Argyle WWTP MN0052451

Alvarado WWTP MNG580171

Warren WWTP MNG580073

Viking WWTP MN0068209

Newfolden WWTP MNG580145

Middle River WWTP MN0052272

Hawkes Co Inc. MN0062715

2.4.6 Socioeconomics

The majority of the Snake River Watershed lies in Marshall County, although small portions of the watershed overlap into Pennington and Polk Counties [NRCS, 2012]. Socioeconomic data for 29 townships and nine municipalities within Marshall County were collected and compiled for this report. Data for subdivisions in Polk and Pennington Counties were omitted because the subdivisions were divided by the watershed boundary into areas too small to accurately represent the amount of the population contributing to the watershed. Data for each subdivision are provided in Appendix A.

The population of the Snake River Watershed in 2012 was 6,414 people based on the American Community Survey of the U.S. Census Bureau. Trends in population showed a slight increase of 0.12 percent between 2000 and 2012. Subdivisions showing growth of more than 10 percent during this period included Viking City, New Folden Township, New Folden City, McCrea Township, Boxville Township, and Big Woods Township. Twelve subdivisions showed a population decline of more than 10 percent during this time period: Vega Township, Parker Township, Oak Park Township, Marsh Grove Township, Holt City, Fork Township, East Valley Township, Comstock Township, Cedar Township, Bloomer Township, Argyle City, and Alvarado City.

The median age of the population in the Snake River Watershed is 45 years, which is almost 10 years older than the national median age of 37. The median age in each subdivision has a broad range. The median age in Viking City is 27.5, while the median age in Fork Township is 65.5. Most townships and municipalities have a median age in the late 40s or early 50s.

The median income for the Snake River Watershed is $50,000 per year, with the lowest median income ($41,667) in Veldt Township and the highest median income ($85,625) in Parker Township. The U.S. median income is $53,046, which is 7 percent higher than the median income in the Snake River Watershed. The most common employment industries are education, health care, and social assistance (20.9 percent); followed by manufacturing (13.9 percent); retail trade (11.4 percent); and agriculture, forestry, fishing and hunting, and mining (11.1 percent).

The educational attainment of the population in the Snake River Watershed exceeds the national average in attaining a high school education and/or an associate’s degree but falls below the national average in

RESPEC RSI-2483 28

RESPEC RSI

RSI

2417

- RSI

- -

- 2483

019

001

Snake River Watershed Snake Conditions ReportRiver Watershed

29 Figure 2-19. National Pollutant Discharge Elimination System-Permitted Discharge Facilities Within the Snake River Watershed.

Snake River Watershed Conditions Report attaining a bachelor’s degree or higher. Overall, approximately 87 percent of the residents have a high school degree or equivalent, and approximately 10 percent have completed an associate’s degree. U.S. averages are over 85 percent for a high school degree or equivalent and more than 7 percent for an associate’s degree.

2.4.7 Local Governments

The Snake River Watershed has two forms of local government established with the purpose of protecting water resources: watershed districts and soil and water conservation districts. Each of these districts is discussed in the following sections.

2.4.7.1 Watershed Districts

The Snake River Watershed is managed by the MSTRWD, which has an office located in Warren, Minnesota (Figure 2-1). Watershed districts are special-purpose units of government authorized under Minnesota Statute 103D. The MSTRWD has a seven-member board appointed by county boards in Marshall and Polk Counties. Marshall County Commissioners appoint six managers and the Polk County Commissioners appoint one manager. Each manager serves a 3-year, staggered term. The purpose of the MSTRWD is to manage water systems (including streams, lakes, groundwater, and wetlands) in a conservative manner while promoting and preserving beneficial uses. The responsibilities of the MSTRWD include controlling floodwaters, reclaiming or filling wet and overflowed land, providing irrigation water, regulating stream flow, controlling or alleviating soil erosion, regulating improvements to riparian properties, and providing groundwater protection.

2.4.7.2 County Soil and Water Conservation Districts

Because the Snake River Watershed spans three counties, three Soil and Water Conservation Districts (SWCDs) operate within the watershed [Northwest Minnesota Soil & Water Conservation Districts, 2014]. The responsibility of the SWCDs is to encourage conservation of soils, water, and related resources. They provide education and resources to help landowners develop their property in an environmentally conscious manner. SWCDs in Minnesota are led by a board of five elected District Supervisors. As shown by the county boundaries in Figure 2-1, the Marshall County, Polk County, and Pennington County SWCDs all have responsibilities in the Snake River Watershed.

RESPEC RSI-2483 30 Snake River Watershed Conditions Report

3.03.0 WATER QUALITY STANDARDS AND IMPAIRMENTS

This chapter describes the classification of the surface waters within the Snake River Watershed, reviews the applicable water quality standards, and lists the existing water quality impairments.

3.1 WATER QUALITY STANDARDS

The federal Clean Water Act (CWA) requires that each state designate beneficial uses for all of their waters and adopt water quality standards to protect each use. In Minnesota, the MPCA is the agency responsible for establishing water quality standards for the state’s rivers, lakes, and wetlands. Water quality standards described by Minnesota Rule Chapter (Minn. R. Ch.) 7050 consist of three elements: (1) classification of the waters with designated beneficial uses, (2) narrative and numeric standards to protect those uses, and (3) nondegradation (antidegradation described in Minn. R. Ch. 7050.0185) policies to maintain and protect existing uses and high-quality waters [MPCA, 2014]. All waters violating water quality standards established by designated uses are classified as impaired and included on a list of impaired waters called the 303(d) list. A Total Maximum Daily Load (TMDL) study is required for impaired waterbodies.

Minn. R. Ch. 7050.0470 lists the designated use classifications for surface waters by major drainage basin. While both the Snake and Middle Rivers are classified as 2B and 3C waters on Minnesota’s 303(d) list, like most waters within the state, the surface waters of the Snake River Watershed have not been specifically listed in Minn. R. Ch. 7050.0470. Minn. R. Ch. 7050.043 provides classifications for unlisted waters and states that all surface waters that are not listed in part 7050.0470 and are not wetlands are classified as Classes 2B, 3C, 4A, 4B, 5, and 6 waters, as defined below (Minn. R. Ch. 7050.430).

Class 2 waters are designated for aquatic life and recreation, with Class 2B waters designated for cool- and warm-water sport or commercial fisheries as well as aquatic recreation, including bathing. Class 3 waters are designated for industrial consumption, with Class 3C waters protected so as to not require a high degree of treatment to allow for use in industrial cooling and materials transport. Class 4 waters are designated for agriculture and wildlife use, with Class 4A waters requiring sufficient quality to support crop irrigation and Class 4B waters protected to support livestock and wildlife. Aesthetic enjoyment and navigation purposes are classified as Class 5 waters. Class 6 waters are designated for all other waters that may have beneficial uses not covered in the previously listed classes, as well as for the protection of border waters. Waters with limited resource value are classified as Class 7; this classification is intended for very few waters in the state.

The designated use class with the most protective water quality standards within the Snake River Watershed is Class 2B waters, which require water to be of sufficient quality to support aquatic life and aquatic recreation. Therefore, the discussion of water quality standards is focused on those pertaining to the aquatic life and aquatic recreation designated uses of Class 2 waters. Numeric and/or narrative criteria have been set for pollutants known to be toxic to aquatic life, as well as for conventional pollutants or water quality characteristics, biological indicators, and constituents that degrade a waterbody’s ability to support aquatic recreation. These criteria list the concentration of a given pollutant a body of water may have while still supporting its designated beneficial use. Essentially, the designated use to the waterbody will be protected as long as these criteria are not exceeded. Water quality standards are discussed in terms of protecting established beneficial uses.

RESPEC RSI-2483 31 Snake River Watershed Conditions Report

Note that the MPCA has recently promulgated new eutrophication and TSS standards for rivers and streams that were approved by the U.S. Environmental Protection Agency (U.S. EPA) in late January 2015. Because these changes occurred after most of this report was compiled, an appendix revision will be completed. Therefore, sections of the following discussion are largely based on the previous stream and river water quality standards.

3.1.1 Aquatic Life Protection Standards

Minn. R. Ch. 7050.0222 includes toxicity-based water quality standards for trace metals (including aluminum, antimony, arsenic, cadmium, chromium, cobalt, copper, lead, mercury, nickel, selenium, silver, thallium, zinc, chloride, and un-ionized ammonia) to protect aquatic life in Class 2B streams. The un- ionized fraction of total ammonia is temperature- and pH-dependent; therefore, total ammonia, temperature, and pH must all be collected concurrently to determine an exceedance of the water quality standard. Because of limited trace metal data in the Snake River Watershed within the most recent 10-year assessment period, only the chloride and un-ionized ammonia targets are shown in Table 3-1. Availability and analysis of chloride and ammonia data are discussed in the following sections, and trace metal data can be found in Appendix C.

Table 3-1. Applicable Toxicity-Based Water Quality Standards

Class 2: B, C, D Standard Notes (mg/L)

Un-ionized Ammonia 0.04 Temperature- and pH-dependent

Chloride 230 Chronic standard

Numeric criteria for the conventional pollutants or water quality characteristics that protect aquatic life in Minnesota’s Class 2B streams are shown in Table 3-2. These constituents include turbidity, pH, and dissolved oxygen (DO). Availability and analysis of data for these constituents within the Snake River Watershed are presented in the following sections.

Table 3-2. Numeric Criteria for Conventional Pollutants or Water Quality Characteristics

Parameter Class 2 Standard

Turbidity (replaced by TSS No more than three samples or 10 percent of samples greater numeric targets) than 25 Nephelometric Turbidity Units

pH 6.5 (minimum)/9.0 (maximum)

DO 5.0 mg/L as daily minimum

Narrative criteria also exist to protect aquatic life beneficial use of Minnesota’s waters. Minn. R. Ch. 7050.0150 Subpart 3 states, “For all Class 2 waters, the aquatic habitat, which includes the waters of the state and stream bed, shall not be degraded in any material manner, there shall be no material increase in undesirable slime growths or aquatic plants, including algae, nor shall there be any significant increase in harmful pesticide or other residues in the waters, sediments, and aquatic flora and fauna; the

RESPEC RSI-2483 32 Snake River Watershed Conditions Report normal fishery and lower aquatic biota upon which it is dependent and the use thereof shall not be seriously impaired or endangered, the species composition shall not be altered materially, and the propagation or migration of the fish and other biota normally present shall not be prevented or hindered by the discharge of any sewage, industrial waste, or other wastes to the waters.” To determine and address habitat degradation, the MPCA conducts biological monitoring of aquatic communities and assesses the health of these communities by using an Index of Biological Integrity (IBI). The IBI incorporates several metrics that, together, provide a way to evaluate the biological system as a whole. The MPCA has developed these indices for fish as well as invertebrate and plant communities in Minnesota’s streams and wetlands and is currently developing IBIs for lake aquatic communities. IBI scores are compared to biocriteria assessment thresholds, which include a combination of the Biological Condition Gradient (BCG) and reference conditions. The current biocriteria threshold is a median of BCG Level 4, which characterizes aquatic communities as having “overall balanced distribution of all expected major groups; ecosystem functions largely maintained through redundant attributes” [Yoder, 2012]. Scores below this threshold indicate that the stream or wetland does not support the aquatic life designated use. Tiered Aquatic Life Use biocriteria are currently under development to tailor biocriteria thresholds to be more protective of high-quality waters, while not requiring highly modified watercourses to meet unattainable conditions [Bouchard, 2014].

3.1.2 Aquatic Recreation Protection Standards

The two conditions that have been identified as threatening the aquatic recreation designated use of Minnesota’s Class 2 waters are the presence of waterborne pathogens, as indicated by an abundance of Escherichia coli (E. coli) bacteria, and lake eutrophication, where excessive nutrient loading can lead to toxic algal blooms. Numeric criteria for E. coli that protect for primary (e.g., swimming) and secondary (e.g., boating and wading) contact recreation are shown in Table 3-3. These criteria are applicable only from April 1 to October 31 (the summer recreation season).

Table 3-3. Water Quality Standards for E. Coli Bacteria

Parameter Class 2B Standard

E. coli Geometric mean of at least five samples taken within a calendar month less than 126 colony-forming units (CFU)/100 mL for April 1 through October 31 sampling period or 90 percent of samples taken over a 10-year period less than 1,260 CFU/100 mL

Eutrophication standards have been developed for Class 2B lakes, shallow lakes, and reservoirs based on ecoregion and for Class 2B rivers and streams based on nutrient region. Because the presence of natural lakes is so limited within the Snake River Watershed, only stream targets are discussed. Class 2B river and stream eutrophication standards exists for three different nutrient regions, and the applicable criteria are shown in Table 3-4. The Snake River Watershed is located in the South River Nutrient Region, as illustrated in Figure 3-1.

RESPEC RSI-2483 33 Snake River Watershed Conditions Report

Table 3-4. Applicable Stream Eutrophication Water Quality Standards for South River Nutrient Region

Parameter (Measured Units Class 2B Standard Over the Summer Period)

Diel DO flux mg/L Less than or equal to 5.0

Chlorophyll a (seston) μg/L Less than or equal to 40

Biochemical oxygen demand (BOD5) mg/L Less than or equal to 3.5 Phosphorus, total μg/L Less than or equal to 150

3.2 IMPAIRMENTS

The entire Snake and the Middle Rivers are currently classified as impaired, with a total of 11 individual impairment listings in the watershed. In all cases, aquatic life is the affected designated use that is not supported. The entire length of the Middle River is listed as impaired for turbidity and DO. The Snake River listings are specific to five separate stream segments and include DO, turbidity, and fish-IBI impairments. Figure 3-2 and Table 3-5 show the impairments for each listed reach within the Snake River Watershed.

RESPEC RSI-2483 34 Snake River Watershed Conditions Report

RSI-2417-14-020

Figure 3-1. Minnesota Nutrient Regions [Heiskary et al., 2013].

RESPEC RSI-2483 35

RESPEC RSI

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Snake River Wate rshed Conditions rshed Report

36 Figure 3-2. Impaired Waters Within the Snake River Watershed.

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Table 3-5. Impaired Waters Within the Snake River Watershed

Assessment Unit Affected Year Placed in Reach Reach Pollutant or EPA Identification Designated Impairment Name Description Stressor Category Number Use Inventory

DO 2010 Snake River Middle River to Red River 09020309-501 Aquatic life 5A Turbidity 2013

DO 2012 Snake River CD 3 to Middle River 09020309-502 Aquatic life 5A Turbidity 2012

DO 2010 Snake River CD 7 to CD 3 09020309-503 Aquatic life 5A Fish 2010

South Branch Snake River to Fish 2010 Snake River 09020309-504 Aquatic life 5A CD 7 Turbidity 2010

DO 2015 Middle River Headwaters to Snake River 09020309-505 Aquatic life 5A Turbidity 2009

Headwaters to South Branch Snake Conditions ReportRiver Watershed Snake River 09020309-506 Aquatic life DO 2012 5C Snake River

Snake River Watershed Conditions Report

4.04.0 EXISTING DATA AND PREVIOUS WORK

4.1 AVAILABILITY OF DATA

Several entities are involved in gathering and reporting data from the rivers, streams, ditches, and impoundments within the Snake River Watershed, including the MSTRWD, International Water Institute (IWI), MPCA, MN DNR, and USGS. Discharge and water quality data were obtained from the beginning of each station’s period of record through December 31, 2013. In cases where data were not available through the end of 2013, they were obtained through the end of the station’s period of record. A summary of the discharge and water quality conditions are included in the following sections, and all data (flow and water quality) obtained for this report have been summarized in a project database file.

In 2013, MPCA conducted intensive watershed-wide monitoring in the Snake River Watershed as part of the statewide watershed approach to restoring and protecting water quality. Analyses of the intensive monitoring program data are still underway by the MPCA, and the assessment results are not scheduled for completion until 2015. Because the water quality data discussed in this report were obtained from MPCA’s database, recent intensive monitoring program data are included in the data discussion and analysis sections. However, standardized biological assessments have been deferred to MPCA’s technical staff, and discussion will be limited to findings from previous reports.

4.1.1 Flow Data

Stream discharge data for active stations were obtained from the DNR/MPCA Cooperative Stream Gaging database, and archived data from inactive stations were obtained from the USGS National Water Information System. Discharge data were obtained at a daily time-step. Table 4-1 lists the data availability for each station within the Snake River Watershed, and Figure 4-1 illustrates the locations of the discharge gages. DNR 68006002/USGS 05085900 was relocated downstream after the Warren Diversion was completed and is no longer active. This station is listed for completeness but is not included in the data analyses.

Table 4-1. Availability of Discharge Data Within the Snake River Watershed

Corresponding Drainage Gage Data Gage Water Quality Area Description Availability Station (mi2)

DNR 68006002/ Snake River Above Alvarado, MN Jan 1995– S004-142 307 USGS 05085900 (Inactive) Sep 1996

DNR 68006001/ Sep 2004– Snake River at Alvarado, MN S004-142 309 USGS 05086000 Dec 2013

DNR 68017001/ Jan 1995– Middle River at Argyle, MN S000-700 255 USGS 05087500 Dec 2013

DNR 68031002/ Nov 2008– Snake River Near Warren, MN S003-101 176 USGS 05085450 Nov 2013

DNR 68032002/ Snake River Above Radium, MN Sep 2004– S004-152 30 USGS 05085420 (Inactive) Oct 2008

RESPEC RSI-2483 38

RESPEC RSI

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2417

- RSI

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- 2483

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Snake River Watershed Snake Conditions ReportRiver Watershed

39 Figure 4-1. Discharge Gage Locations Within the Snake River Watershed.

Snake River Watershed Conditions Report

4.1.2 Water Quality Data

Water quality data were obtained from MPCA’s Environmental Quality Information System (EQUIS) database. These data have been collected as part of several different monitoring programs conducted by multiple organizations, but they are submitted to the MPCA and housed in a central database. Data were retrieved for the entire period of record for each site, but analyses were limited to the most recent 10-year assessment period for common water quality constituents. A complete list of water quality stations, sample parameters, and counts can be found in Appendix D. Figure 4-2 shows the locations of the selected water quality and biological monitoring sites in the Snake River Watershed listed in Table 4-2.

4.2 OTHER APPLICABLE STUDIES

Several existing studies synthesize and summarize the hydrologic and water quality conditions in the Red River of the North Basin, many of which include data that are either derived from or applicable to the Snake River Watershed. These studies include projects that support flood-reduction strategies for the Red River of the North. These have included the acquisition of Light Detection and Ranging (LiDAR) data for the entire basin through the Red River Basin Mapping Initiative and basinwide hydrologic studies through the IWI and Red River Watershed Management Board (RRWMB), with support from the U.S. Army Corps of Engineers (USACE). Further, basinwide water quality monitoring, analyses, and biological assessments have been conducted by the MPCA, USGS, and RRWMB. Additionally, a basinwide turbidity TMDL study is currently underway to address 17 impairments throughout the Red River Basin, with an approved TMDL completed for the Ottertail River. An International Joint Commission (IJC) study is currently underway to define stressor-response-based nutrient targets for the Red River of the North.

Studies specific to the Snake River Watershed projects and conditions have also been conducted and these include management plans from both the MSTRWD and Marshall County, NRCS’s Rapid Watershed Assessment, and stream surveying and biological assessments conducted by the MN DNR. The MSTRWD’s Watershed Management Plan also discusses current and ongoing projects in the watershed to improve water quality while mitigating flooding impacts, such as the Agassiz Valley Project. Notable current projects in the Snake River Watershed include a 2-year geomorphology study underway by the MN DNR and the assessment of the MPCA’s intensive monitoring program data, which will be used to determine impaired waters. Reports associated with the above-mentioned studies are listed in Table 4-3 as well as in the supplementary report bibliography.

4.2.1 Hydrologic and Hydraulic Models

The MSTRWD authorized developing a Hydrologic Engineering Center Hydrologic Modeling System (HEC- HMS) hydrologic model for the Snake River Watershed to help improve understanding of the response to storm and melt events within the watershed. HEC-HMS is a USACE model that is typically used to simulate storm (or snowmelt) events; although it is not typical, HEC-HMS can also be set up to run continuous simulations. Recent basinwide HEC-HMS hydrologic modeling has been conducted for the entire Red River of the North and its tributaries, including the Snake River Watershed. This effort has been undertaken by the RRWMB with support from the USACE to help achieve a 20 percent reduction in peak flow from the 1997 flood. Many of the Red River of the North flood-reduction studies that support this work are listed in Table 4-3. To support this work, high-resolution (1 meter) LiDAR data were obtained and used to identify drainage patterns and potential areas for detention storage.

RESPEC RSI-2483 40

RESPEC RSI

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- -

- 248

023

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Snake River Watershed Snake Conditions ReportRiver Watershed

41 Figure 4-2. Water Quality Monitoring Locations.

Snake River Watershed Conditions Report

Table 4-2. Availability of Water Quality Data Within the Snake River Watershed (Stations are organized by major river and ordered by location from upstream to downstream)

Chlorophyll Fecal Inorganic Kjeldahl Ortho- Station Ammonia BOD Chloride DO E. coli Mercury TOC pH Phosphorus Conductivity Temperature TDS TSS Transparency Turbidity a Coliform Nitrogen Nitrogen Phosphate

Middle River S004-106 10 10 15 8 10 8 15 10 15 15 12 15 3 S002-988 30 30 34 30 29 35 S002-987 27 27 28 27 26 30 S007-440 10 10 13 8 10 8 13 10 13 13 10 13 S002-989 10 10 65 20 19 27 19 72 27 76 72 19 19 57 75 S004-215 29 29 29 29 26 S000-700 12 10 94 19 13 1 93 13 94 94 20 88 48 S000-697 12 12 12 12 S003-691 17 18 70 26 20 39 6 24 77 39 77 77 20 50 60 66 South Branch Snake River S007-311 4 4 4 4 4 4 S007-310 5 5 4 5 5 5 S002-108 64 34 33 61 34 63 64 35 60 61 Swift Coulee S001-598 169 Snake River S004-152 16 11 8 36 19 18 31 7 18 43 31 43 43 18 20 29 43 S003-101 18 11 8 73 18 16 8 72 16 76 74 20 68 73 S002-986 37 34 39 37 33 37 S002-994 42 18 18 18 47 18 48 49 18 18 31 49 S004-214 10 10 13 8 10 8 13 10 13 13 10 13 S004-142 23 18 8 74 26 58 51 2 38 73 58 74 74 56 74 89 S003-692 26 21 8 66 26 18 45 15 22 73 45 73 73 18 45 57 60 S000-185 104 12 68 28 229 45 270 143 5 25 233 243 268 237 232 226 215 321 Grand Total 268 12 197 60 986 223 93 593 255 5 27 417 1,024 591 1,040 1,025 93 541 1,072 999

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Table 4-3. Previous Studies Applicable to the Snake River Watershed (Page 1 of 3)

Category Year Agency Author(s) Title

Stoner, J. D., Water Quality in the Red River D. L. Lorenz, of the North Basin, Minnesota, 1998 USGS R. M. Goldstein, North Dakota, and South Dakota, M. E. Brigham, and 1992–95 T. K. Cowdery. Water Quality of Streams in the Red River of the North Basin, 2005 USGS Tornes, L. H. Minnesota, North Dakota, and South Dakota, 1970–2001 State of the Red River of the Paakh, B., North—Assessment of the 2003 MPCA/ 2006 W, Goeken, and and 2004 Water Quality Data for Red River of the RRWMB North: Water D. Halvorson the Red River and its Major Quality Minnesota Tributaries Lower Otter Tail River Turbidity— Total Maximum Daily Load Report 2006 MPCA MPCA (first of 17 turbidity TMDLs underway in the Red River Basin) Nutrients, Suspended Sediment, and Pesticides in Water of the Red 2007 USGS Christensen, V. G. River of the North Basin, Minnesota and North Dakota, 1990–2004 Emmons & Oliver Red River Biotic Impairment 2009 MPCA Resources, Inc. Assessment

Technical Paper No. 1: An Apfelbaum, S. and Overview of the Impacts of Water 1998 RRWMB L. Lewis Level Dynamics (“Bounce”) on Wetlands

Technical Paper No. 2: Small Eppich, D., Wetlands Use for Stormwater 1998 RRWMB S. Apfelbaum, Runoff Management in the Red and L. Lewis Red River of the River of the North Basin North: Flood Reduction Technical Paper No. 3: The Effectiveness of Agricultural Best 1998 RRWMB Larson, G. Management Practices for Runoff Management in the Red River Basin of Minnesota

Technical Paper No. 4: Siting and Anderson, C. and 1998 RRWMB Design of Impoundments for Flood L. Lewis Control in the Red River Basin

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Table 4-3. Previous Studies Applicable to the Snake River Watershed (Page 2 of 3)

Category Year Agency Author(s) Title

Aadland, L., S. Technical Paper No. 5: Stream 1998 RRWMB Jutila, and C. Restoration for Flood Damage Anderson Reduction in the Red River Technical Paper No. 6: Watershed 1998 RRWMB Solstad, J. Modeling of Various Flood Damage Reduction Strategies Woodbury, L. and Technical Paper No. 7: Flood 1998 RRWMB R. St. Germain Frequency Based Design Technical Paper No. 8: Technical and Implementation of a Flood 1998 RRWMB Scientific Advisory Damage Reduction Strategy in the Committee Red River Basin Red River of the Eppich, D., Technical Paper No. 9: Red River North: Flood 2003 RRWMB M. MacGregor, Basin Flood Damage Reduction Reduction and A. Kean Project Monitoring Program (continued) Technical Paper No. 10: Basin 2003 RRWMB Johnson, B. Strategy: Hydrologic Analysis

Technical Paper No. 11: Red River Anderson, C. 2004 RRWMB Basin Flood Damage Reduction and A. Kean Framework Apfelbaum, S., Technical Paper No. 12: Wetland 2004 RRWMB D. Eppich, and Hydrology & Biodiversity in the J. Solstad Red River Basin, Minnesota Technical Paper No. 13: On- Van Offelen, H. Channel Storage in the Red River 2005 RRWMB and A. Kean Basin—Guidelines for Site Selection, Design, and Operation 2007 MN DNR Groshens, T. Red River Basin Stream Survey Report: Snake River and Tamarac River Watersheds 2006

2007 UND EERC Kurz, B. A., An Evaluation of Basinwide, X. Wang, Distributed Storage in the Red L. de Silva, River Basin: the Waffle® Concept Snake River S. K. Hanson, Watershed M. D. Kurz, Studies W. D. Peck, T. K. Simonsen, and E. N. Steadman 2011 MSTRWD MSTRWD Final Ten Year Watershed Management Plan—May 2011— Middle-Snake-Tamarac Rivers Watershed District

RESPEC RSI-2483 44 Snake River Watershed Conditions Report

Table 4-3. Previous Studies Applicable to the Snake River Watershed (Page 3 of 3)

Category Year Agency Author(s) Title

2012 Marshall Marshall County Marshall County Local Water County Water Resources Management Plan 2007–2015— Water and Advisory Committee Amended Plan for years 2012– Land Office 2015 2012 USDA– NRCS Rapid Watershed Assessment: Snake River NRCS Snake River (MN) HUC: 09020309 Watershed Studies (continued) 2015 MPCA Burke, M. Initial Hydrology Calibration and Validation of the Snake and Grand Marais Watershed HSPF Models 2014 MPCA Burke, M. Snake River Watershed and Grand Marais Creek Watershed Model Development

Hydraulic models have also been developed using the USACE’s Hydrologic Engineering Center River Analysis System (HEC-RAS) model. HEC-RAS simulates one-dimensional steady and unsteady flow, river hydraulics, sediment transport, and temperature. In the Snake River Watershed, HEC-RAS has been used to help identify the floodplain and support water development and restoration projects. This model has also been used in conjunction with the Soil and Water Assessment Tool (SWAT) model (described below) to support the University of North Dakota Energy & Environmental Research Center’s (UND EERC) Waffle Project, which investigates the potential for fields, raised roads, and drainage structures to act as temporary storage for floodwaters. Before the year 2000, the USACE’s HEC-2 model was used to support the MSTRWD’s flood insurance studies, with earlier modeling based on the NRCS’s WSP2 program [MSTRWD, 2011].

4.2.2 Water Quality Modeling

The UND EERC has developed SWAT models of the entire Red River Basin through the Waffle Project to provide continuous hydrology simulations. The results from these models were supplied as input to the HEC-RAS models described above to identify and quantify floodwater storage potential. The Snake River Watershed SWAT model was updated in 2009 to include simulation of sediment, with the goal of assessing the factors that contribute to the watershed’s turbidity impairments. The SWAT model identified sediment sources from both in-stream and overland flow processes and indicated that significant reductions to sediment loading could be achieved by implementing conservation tillage practices and field buffers [Kurz et al., 2007].

A Hydrologic Simulation Program–Fortran (HSPF) water quality model is currently under development for the Snake River Watershed as part of MPCA’s statewide modeling program. The Snake River Watershed currently provides continuous hydrology predictions as an hourly time-step, and it is currently being updated to provide water quality simulations. The updated model will generate simulated time series for temperature, nitrogen, ammonia, phosphorus, DO, BOD, and algae (chlorophyll a), as well as sand, silt, and clay sediment fractions. The modeled output will be used to support MPCA activities, including conventional parameter TMDL development, in-stream nutrient criteria compliance testing, future support for Municipal Separate Storm Sewer System (MS4) permitting, and point-source permitting.

RESPEC RSI-2483 45 Snake River Watershed Conditions Report

55..00 WATER QUALITY ANALYSIS

The purpose of this data analysis is to provide a better understanding of the current water-quantity and quality conditions in the Snake River Watershed. The intention is not to replace or duplicate the more thorough analyses the MPCA conducts to assess Minnesota’s waters and determine impairments; rather, the analysis provides a general summary of existing conditions over the most recent assessment period. Where applicable, observations are compared to existing and proposed water quality standards, with the caveat that observed exceedances do not necessarily indicate impairments. The MPCA (2014) has outlined assessment criteria for determining impairment for individual water quality parameters that often require a specific number of exceedances and/or occurring over specific time periods. MPCA’s professional judgment team will perform an assessment of waters within the Snake River Watershed that includes observations from the intensive monitoring program in 2015.

Data summaries are included for discharge, chloride, ammonia, DO, temperature, pH, turbidity, TSS, transparency, E. coli, and total phosphorus. The water quality constituents are grouped according to applicable water quality standards, and summaries include a brief description of the constituent followed by a discussion of the observed data. Data analyses for the above-listed constituents are organized as follows:

 Flow Analysis  Aquatic Life—Parameters with Toxicity-Based Standards  Aquatic Life—Conventional Parameters  Aquatic Life—Biological Indicators  Aquatic Recreation—E. coli Bacteria  Aquatic Recreation—Eutrophication Parameters.

Monitoring data are summarized by sampling site location and presented in order from upstream to downstream (from left to right in figures showing multiple locations). Discharge data are summarized in plots that show a time series of all sites and flow-duration curves for each site. Water quality data are summarized using box-whisker plots. The box-whisker plots can be interpreted as follows: the top of the box represents the value that 75 percent of observed values are at or below, while the bottom of the box represents the 25th percentile value. The bisector represents the median value of all observations. The notched whiskers represent the maximum and minimum values (excluding outliers) that are defined as being greater than 1.5 times the interquartile range and depicted by the red crosses.

5.1 FLOW ANALYSIS

Discharge data were summarized for the four sites within the Snake River Watershed with continuous discharge data for the most recent 10-year assessment period, including MN DNR gages 68032002 located on the Snake River near Radium, 68031002 located on the Snake River above Warren, 68006001 located on the Snake River above Alvarado, and 68017001 located on the Middle River at Argyle. No continuous gaging station exists on the Snake River below its confluence with the Middle River. These data are displayed in order from upstream to downstream with Snake River sites shown in blue and Middle River shown in green. Water quality site numbers are also shown to provide context for colocated sampling sites.

RESPEC RSI-2483 46 Snake River Watershed Conditions Report

As shown in Figure 5-1 and Table 5-1, MN DNR gage 68017001 on the Middle River is the only site with continuous data throughout the entire evaluation period. Two of the gages on the Snake River (68032002 and 68006001) are missing measurements in the winter and early spring (November through March). The time series (Figure 5-1) and flow-duration curves (Figure 5-2) show the range and timing of discharge observations at each site. Table 5-1 shows the calculated 7-day low flow, average annual flow, and peak flow for each gaged site. Keep in mind that the two sites without winter measurements may be skewed toward higher values. Monthly boxplots were created to further show seasonality at each site and are provided in Appendix C.

RSI-2417-14-024

Figure 5-1. Discharge Time Series.

The lowest 7-day average flow values were typically observed in the late summer and fall (late August through early October) and winter months (December through early March). The values ranged from 0 cubic feet per second (cfs), observed at least once at each location, to 2.36 cfs, observed in 2009 on the Middle River. Average annual flow values ranged from 3 cfs, observed in 2008 at the most upstream gage on the Snake River (68032002), to 168 cfs, observed at the Middle River site (68017001) in 2005. Peak flows typically occurred in April, coinciding with spring snowmelt, and ranged from 56 cfs, observed at the Snake River’s most upstream gage (68032002) in 2008, to 3,500 cfs, observed in 2006 at the Middle River site (68017001). The Middle River site typically exhibited higher peak flow values and higher average annual flows than the most downstream Snake River site (68006001) for the years when both sites had complete datasets (2008–2013), even though the downstream Snake River site receives water from a larger drainage area. Local topography and the flood mitigation efforts on the Snake River attribute to the higher peak flows.

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RESPEC Table 5-1. Summary Statistics for Each Discharge Gage

RSI

- (a) (b) 2417

Flow Gage DNR 68032002 DNR 68031002 DNR 68006001 DNR 68017001

RSI

- - 2483 Water Quality Site S004-152 S003-101 S004-142 S000-700 14

001

Snake River Above Snake River Near Snake River at Middle River at

Description Radium, MN Warren, MN Alvarado, MN Argyle, MN Drainage 30 mi2 176 mi2 307 mi2 255 mi2

Flow Flow Flow Flow (cfs) (cfs) (cfs) (cfs) Water Year 7-Day Avg. 7-Day Avg. 7-Day Avg. 7-Day Avg. Peak Peak Peak Peak Low Ann. Low Ann. Low Ann. Low Ann.

2004 0.15 101 1,950 2005 0.05 30 392 1.64 168 2,430 2006 0.00 23 810 0.00 120 2,770 0.34 103 3,500 2007 0.00 12 226 0.00 55 838 0.37 48 572 2008 0.00 3 56 0.00 13 264 0.07 19 144 2009 0.43 103 1740 0.40 119 1,600 2.36 155 1,770

2010 0.00 67 864 0.04 76 1,320 1.56 104 1,550 Snake River Watershed Snake Conditions ReportRiver Watershed 2011 0.00 95 719 1.45 109 753 1.11 157 1,580 2012 0.00 5 109 0.00 12 502 0.00 15 388 2013 0.00 36 755 0.00 54 1,120 0.16 36 1,350

(a) Dataset does not include winter values. (b) Dataset does not include winter values for Water Years 2004–2007.

Snake River Watershed Conditions Report

RSI-2417-14-025 Flow Duration Curves 10000 68032002/ S004-152 1000 68031002/ S003-101 68006001/ S004-142

100 68017001/ S000-700

Dischaarge (cfs) 1

0.1

0.01 0 20 40 60 80 100 Exceedance Probability (%)

Figure 5-2. Flow-Duration Curves.

5.2 AQUATIC LIFE—PARAMETERS WITH TOXICITY-BASED STANDARDS

Toxicity-based water quality standards address chloride because high concentrations can harm aquatic organisms by interfering with their ability to maintain the proper concentration of electrolytes in their body fluids. Chloride is introduced to waters from both natural and anthropogenic sources. It can be introduced naturally to surface and groundwater through leaching and weathering of rocks, minerals, and salt deposits, and from atmospheric deposition. Anthropogenic sources of chloride (generally from dissolution of sodium chloride and magnesium chloride compounds) can include road deicing salts, water and wastewater treatment, landfills, and agricultural applications. The chronic standard for Minnesota’s Class 2 waters is 230 mg/L.

Boxplots and summary statistics for chloride measurements taken in the Snake River Watershed over the most recent assesment period are shown in Figure 5-3. Overall, higher concentrations were observed on the Snake River than on the Middle River, and chloride concentrations generally increased from upstream to downstream. Median choride concentrations ranged from 8.51 mg/L to 20.4 mg/L, and all observations were well below the water quality standard of 230 mg/L. The highest median chloride concentrations were observed at Snake River Site S003-692, which is located just above the confluence of the Snake and Middle Rivers. The influence of the Middle River can be observed in the lower median chloride concentrations in the most downstream location on the Snake River (Site S00-185). However, this site, which had the most observation points, exhibited the highest maximum chloride concentration of 70.6 mg/L.

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50 Figure 5-3. Chloride Boxplots and Summary Statistics.

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Toxicity-based water quality standards have been defined for a form of ammonia called un-ionized ammonia. Ammonia is a colorless gas, often found in fertilizer, fuel, and disinfectants, that reacts with water to form ammonium. The term ammonia often refers to the two species at equilibrium in water, and standard water quality tests for ammonia usually measure total ammonia (un-ionized ammonia plus ammonium). The equilibrium concentration of these two species in water; hence, the fraction of un- ionized to total ammonia, is dependent on pH and temperature. Therefore, total ammonia, pH, and temperature measurements must be taken concurrently to determine the un-ionized ammonia concentration. High concentrations of un-ionized ammonia can interfere with the metabolism in aquatic species, and Minnesota’s water quality standards for Class 2 waters are 0.04 mg/L.

Total ammonia concentrations were summarized and compared to the typical summer concentration range for unimpacted streams in the LAP ecoregion (0.08–0.20 mg/L) [McCollor and Heiskary, 1993]. Boxplots and summary statistics for total ammonia measurements taken in the Snake River Watershed over the most recent assessment period are shown in Figure 5-4. Median concentrations ranged from 0.04 to 0.0795 mg/L and are within the typical ecoregion range. General patterns of increasing or decreasing concentrations from upstream to downstream were not observed. The highest total ammonia concentrations were monitored at the most downstream Snake River site (S00-185), where a concentration of 0.72 mg/L (nine times greater than a typical summer ecoregion concentration) was observed. It is recommended that further analysis be conducted with paired total ammonia, pH, and temperature data to determine if un-ionized ammonia water quality standard exceedances have occurred.

5.3 AQUATIC LIFE—CONVENTIONAL PARAMETERS

5.3.1 Dissolved Oxygen

Dissolved oxygen is as essential for most aquatic organisms as air-based oxygen is for terrestrial life. In the water, DO is a measure of the amount of oxygen available for aquatic life, with concentrations below 5 mg/L causing stress to many aerobic life forms. Stress and mortality risks increase as oxygen concentrations decline below 5.0 mg/L; hence, this level is the minimun DO threshold for Class 2 waters. Specific sampling protocols exist to determine impairment that require at least 20 obervations taken before 9 a.m. during the months of May–October over a 2-year period. Water temperature, respiration, and photosynthesis by aquatic plants impact the diurnal and seasonal fluctuations of DO. The entire length of the Middle River and four of the five assessment reaches on the Snake River are currently impaired for low DO.

Included in the newly promulgated river eutrophication standards is Diel Dissolved Oxygen Flux, or the fluction of daily oxygen levels within streams. Nighttime conditions typically consume oxygen due to respiration, and daytime concentrations increase because of plant-related photosynthesis. The difference between the low- and high-period daily oxygen concentrations in rivers is referred to as diel (daily) dissolved oxygen flux. As the concentration of phoshorus increases, there can be an increase in algae, organic matter, and associated bacteria. The combined effect can result in increased daytime and reduced nighttime dissolved oxgyen values. Hence, the new river standards include total phosphorus (cannot exceed 150 parts per bilion [ppb]), chlorophyll a (cannot exceed 40 ppb), 5-day biochemical oxgyen demand (cannot exceed 3.5 mg/L), and diel oxygen flux (cannot exceed 5.0 mg/L net daily difference). Exceedance of the phosphorus standard along with one or more of the response variables monitored over the summer growing season are required for evaluating compliance to the new standard.

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52 Figure 5-4. Total Ammonia Boxplots and Summary Statistics.

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Figure 5-5 summarizes the DO data for the Snake River Watershed over the recent 10-year asessment period. All data (as opposed to only samples taken before 9 a.m.) were included in this analysis; therefore, the values may be skewed higher when compared to a formal assessment. Three tributary sites that include data upstream and downtream from the Agassiz Valley impoundment are included, along with data from the Snake and Middle Rivers sampling locations. Of the sites shown in Figure 5-5, only the tributary sites and Snake River Sites S003-101, S002-986, and S002-944 are located on reaches that are not listed as impaired. The lowest DO measurement (0.85 mg/L) was taken at the most downstream Snake River site (S000-185).

5.3.2 Temperature

Although water quality standards do not exist for Minnesota’s Class 2B waters, these data are included here because other constituents with water quality criterion, such as DO and pH, are directly related to water temperature. For example, higher temperatures are associated with the formation of algae, which can consume DO and create conditions that make a stream susceptible to impairment. Temperature measurements are summarized and compared to the typical summer range for unimpacted streams in the of LAP ecoregion of 72 to 87 degrees Fahrenheit (°F).

Boxplots and summary statistics for temperature measurements taken in the Snake River Watershed over the most recent assesment period are shown in Figure 5-6. The maximum temperature observed at each location ranged from 63.8 to 83.9°F. All of these measurements are within the ecoregion range. The highest temperatures were observed on the Snake River just before Site S003-602 and after Site S000-185 (its confluence with the Middle River), with values of 82.2 and 83.9°F, respectively.

5.3.3 pH

The pH of water indicates the degree of its acidity or alkalinity. A value of 7.0 incicates a neutral pH, lower values are acidic, and higher value are basic or alkaline. In natural waters, pH is primarily controlled by local geology; however, precipitation and wastewater and/or mining discharges can also play an important role. Very high and very low pH levels are mining discharges and are potentially harmful to aquatic life. High pH can also increase the toxicity of other chemicals, such as ammonia. Minnesota’s standard for Class 2 waters require pH values to remain between 6.5 and 9.0.

Boxplots and summary statistics are shown in Figure 5-7 for pH measurements taken in the Snake River Watershed over the most recent assesment period. The maximum pH observed at each location ranged from 8.08 to 11.2. The highest pH value of 11.2 was observed on the Middle River just downstream of the town of Newfolden. The minimum pH values observed at each location ranged from 4.4 to 7.68, with the lowest pH value of 4.4 observed on the Snake River at Site S003-602 just before its confluence with the Middle River.

5.3.4 Turbidity

The following analysis was conducted using turbidity data, but the water quality standard for turbidity has recently been replaced by a TSS standard. Turbidity is a measurement of water clarity with suspended materials in the water column scattering light to make the water appear cloudy. High turbidity levels can negatively impact the feeding and spawning habits of fish and interfere with gill functions. Minnesota’s water quality standard for turbidity in Class 2B streams was 25 Nephelometric Turbidity Units (NTUs).

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54 Figure 5-5. Dissolved Oxygen Boxplots and Summary Statistics.

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55 Figure 5-6. Temperature Boxplots and Summary Statistics.

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56 Figure 5-7. pH Boxplots and Summary Statistics.

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Turbidity impairments were identified for three of the five assessment reaches on the Snake River. The MPCA allowed for the use of transparency and/or TSS data to serve as a surrogate for assessments when turbidity data are insufficient (i.e., less than 20 observations). These constituents are discussed below.

Turbidity has been historically measured using different instruments that report results in different units, including NTUs, measured using use a white light (400–680 nanometer [nm]) with a 90-degree incident beam geometric detector angle; Nephelometric Turbidity Ratio Units (NTRUs), measured using a white light (400–680 nm) with the detector geometry at 90 degrees plus other angles and an algorithm to compute a single value; and Formazin Nephelometric Units (FNUs), measured using a monochrome light (780–900 nm) with a 90-degree incident beam geometric detector angle [Tornes, 2005]. Turbidity measurements with all three of these units were present in the Snake River Watershed data.

Previous MPCA turbidity studies indicated that NTU and NTRU data can be directly compared, while a regression analysis should be performed to determine if paired FNUs and NTUs are well correlated. If a good correlation can be made, the FNU data can be converted into interpreted NTU data, then the NTU, NTRU, and FNU measurements can be combined into a single dataset [RTI International, 2007; Johnson, 2008; Pomme de Terre River Watershed Association, 2011]. Of the turbidity samples collected in the Snake River Watershed, 69 percent were single samples in units of NTU/NTRU, 15 percent were paired samples in units of both NTU/NTRU and freshwater monitoring unit (FMU), and 16 percent were single samples in units of FMU. Figure 5-8 illustrates that the paired samples were well correlated (r2 = 0.94) as well as the equation used to convert the nonpaired FMU data. For simplicity, all turbidity data will be referred to as having NTUs for the remainder of the discussion.

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Figure 5-8. Turbidity Unit Regression.

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Boxplots and summary statistics for turbidity measurements taken in the Snake River Watershed over the

RSI most recent assesment period are shown in Figure 5-9. Values generally increase from upstream to

- downstream on both the Snake and Middle Rivers and on the McCrea impoundment tributary sites. 2417 Median and maximun observed values on the Snake River range from 3.97 to 44.93 NTUs and 39 to

- 1,551 NTUs, respectively. On the Middle River, the median and maximun measurements range from 2.2 14

- to 52.7 NTUs and 7.06 to 844 NTUs, respectively. A maximun value of 1,551 NTUs was observed at the 001 most downstream location on the Snake River (Site S000-185).

Transparency indicates water clarity and can be used as a surrogate for turbidity in cases where turbidity data are insufficient to perform an assessment (i.e., greater than 20 samples). A transparency measurement of less than 20 centimeters is akin to an exceedance of the 25 NTUs standard. Transparency data are often more prevalent than turbidity data because it is an inexpensive measurement taken using a transparency tube. Figure 5-10 shows boxplots and summary statistics for transparency measurements taken within the Snake River Watershed. These data correlate well with the turbidity measurements shown in Figure 5-9 and show a reduction in transparency from upstream to downstream in the Snake and Middle Rivers, as well as the McCrea impoundment sites. Additional data are shown for the Swift Coulee site (S001-598), where one of the four measurements falls below the 20-centimeter standard.

5.3.5 Total Suspended Solids

Where turbidity, transparency, and TSS measurements all account for organic matter as well as sediment, TSS provides a better understanding of sediment loading to a waterbody. Sediment can be contributed to a waterbody from erosional processes associated with overland flow, as well as through bed and bank erosion. The WRAPS will include a sediment source assessment and the development of a sediment budget to help define the dominant sediment delivery processes in the Snake River Watershed.

The MPCA has recently promulgated and received U.S. EPA approval for replacing river turbidity standards with TSS standards that were derived by river nutrient regions. Tributaries of the Red River of the North were included in the Southern River Nutrient Region with a specified numeric standard of 65 mg/L and a required 90 percent compliance rate for samples obtained over the time period of April 1 through September 30. Included in the MPCA technical support documentation of the new standard is language that describes samples from nonstorm events used in developing the new TSS numeric standard [MPCA, 2007]. Hence, details will be forthcoming as to compliance evaluations for this parameter.

TSS observations are summarized in Figure 5-11. As with the turbidity and tranparencey observations, values increase from upstream to downstream on both the Snake and Middle Rivers, with the highest values observed at the Snake River’s most downstream site (S000-185). Median and maximun values observed on the Snake River range from 3 to 60 mg/L and 35 to 2,640 mg/L, respectively, with the highest concentrations associated with spring flooding events. Median and maximum TSS concentrations on the Middle River range from 2.5 to 70.5 mg/L and 9 to 300 mg/L, respectively. Both systems exceed the North Central Hardwood Forests ecoregion’s standard of 100 mg/L.

5.4 AQUATIC LIFE—BIOLOGICAL INDICATORS

Biological indicators provide a holistic picture of ecosystem health and a way to measure a waterbody’s ability to support aquatic life that goes beyond water chemistry observations. Several indicators are

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59 Figure 5-9. Turbidity Boxplots and Summary Statistics.

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60 Figure 5-10. Transparency Boxplots and Summary Statistics.

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61 Figure 5-11. Total Suspended Solids Boxplots and Summary Statistics.

Snake River Watershed Conditions Report assessed, including water chemistry, habitat structure, energy sources, flow regime, biotic interactions, and biological integrity. Indices of biological integrity have been developed for both fish and aquatic invertebrates that help to qualify and quantify the presence of a healthy, diverse, and reproducing aquatic community given the physical setting of the system in question.

The MPCA is currently assessing biological data collected in 2012 and 2013 as part of its intensive monitoring program, and this report will be updated when those results become available. However, a stream survey was conducted by the MN DNR that included streams in the Snake River Watershed, and the results outlined in the accompanying report are discussed below [Groshens, 2007].

The MN DNR calculated IBI scores at two locations along the Snake River and four locations on the Middle River, as shown in Figure 5-12. Two different sets of IBI scoring metrics were used based on the drainage area. The most upstream site on the Middle River was compared to standard metrics for stations with a drainage area less than 200 square miles, while the remaining sites were scored using metrics for stations with a drainage area of 200 to 1,500 square miles. The IBI metrics are related to species richness and composition, trophic composition, lithophilic spawning fish, tolerant fish, and fish abundance [Groshens, 2007]. Table 5-2 shows the IBI scores from the 2006 survey. Both sites on the Snake River and three of the four sites on the Middle River received “Fair” IBI scores. The most upstream site on the Middle River received a “Good” IBI score. Additional information on the results can be found in Groshens [2007].

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Figure 5-12. Minnesota Department of Natural Resources Assessment Locations [Groshens, 2007].

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Table 5-2. Minnesota Department of Natural Resources Index of Biological Integrity Scores

Biotic Integrity Stream Station Number IBI Score Classification

Snake River SR201 32 Fair Snake River SR401 34 Fair Middle River MR101 34 Fair Middle River MR302 44 Good Middle River MR501 36 Fair Middle River MR601 36 Fair

5.5 AQUATIC RECREATION—E. COLI BACTERIA

E. coli is a bacteria that is used to indicate the presence of waterborne pathogens. It is commonly found in the digestive systems of humans and animals and is generally believed to be short-lived in the environment. Thus, high levels of E. coli in a waterbody can indicate fecal and associated pathogen contamination. Sources of E. coli can include human or animal waste contributed from wildlife, agricultural operations, and septic system or wastewater treatment facility failures. Minnesota’s E. coli standards for Class 2 waters require that the monthly geometric mean for at least five samples remain below 126 organisms/100 mL. The measurement units of most probable number (MPN) and CFU/100 mL are both used and are interchangeable. The standard for Class 7 waters is 1,260 organisms/100 mL. These criteria are applicable only from April 1 to October 31, which is the summer recreation season when people are likely to be in contact with water.

Figure 5-13 shows boxplots and summary statistics for E. coli measurements in the Snake River Watershed. All samples were collected over the recent 10-year assessment period during the summer recreation season. All of the sampling locations on both the Snake and Middle Rivers show at least one sample exceeding the 126 MPN/100 mL standard; however, monthly geometric means were not calculated. The median values range from 42 to 121.4 MPN/100 mL on the Snake River and 41.4 to 81.6 MPN/100 mL on the Middle River. Both the highest and lowest values were observed at the most downstream site on the Snake River (Site S000-185). Further data analysis is recommended to determine whether or not sufficient data exists to calculate monthly geometric means for all sampling locations. If so, these analyses should be conducted to determine whether or not E. coli impairments are present.

5.6 AQUATIC RECREATION—EUTROPHICATION PARAMETERS

Eutrophication refers to the enrichment of bodies of fresh water by inorganic plant nutrients (e.g., nitrate or phosphate). It may occur naturally but can also be the result of human activity (eutrophication from fertilizer runoff and sewage discharge) and is particularly evident in slow-moving rivers and shallow lakes [Lawrence et al., 1998]. The added nutrients often result in increased algal growth, leading to increased biochemical oxygen demand and, in turn, decreases in DO that can potentially harm fish and other

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64 Figure 5-13. E. coli Bacteria Boxplots and Summary Statistics.

Snake River Watershed Conditions Report aquatic life. As discussed in Section 3.1, eutrophication water quality standards exist for DO flux, chlorophyll a, BOD, and TP. Minnesota’s new stream eutrophication standards were developed regionally, with the Snake River Watershed located in the South River Nutrient Region. Exceedance of the phosphorus standard along with one or more of the response variables monitored over the summer growing season are required for evaluating compliance to the new standard. DO data were presented in Section 5.3 and a more detailed analysis will reveal if the daily flux exceeds the standard of 5 mg/L. The remaining constituents are discussed below.

Chlorophyll a measurements provide an indication of the amount of algae present in a waterbody, and water quality standards for chlorophyll a are 40 micrograms (μg)/L. Boxplots and summary statistics for chlorophyll a measurements within the Snake River Watershed are shown in Figure 5-14. Limited data were available for five sites along the Snake River, with only Snake River Site S000-185 having more than 20 samples, and no chlorophyll a data were available on the Middle River. Median values ranged from 3 to 35 μg/L, which are all below the new water quality standard. However, two Snake River sites exhibited measurements greater than 40 μg/L, and a maximum value of 57 μg/L was observed at Snake River Site S004-142.

Biochemical oxygen demand refers to the amount of DO needed by aerobic organisms to break down organic matter in a waterbody in a given time period. Minnesota’s stream standard for BOD over a 5-day time period is 5 mg/L. As seen in Figure 5-15, BOD data were only available at the Snake River’s most downstream site (Site S00-185). Values ranged from 1.4 to 3.3 μg/L with a median of 2.1 μg/L. The standard of 3.5 mg/L was not exceeded.

Phosphorus is often the limiting nutrient for algal growth in Minnesota’s lakes and rivers. Contributions can come from both natural and anthropogenic sources, such as geologic formations, soil composition, detergents, and fertilizers, but it is often associated with agricultural runoff. Minnesota’s TP eutrophication standards for the South River Nutrient Region streams is 0.15 mg/L. Boxplots and summary statistics are shown in Figure 5-16 for TP measurements within the Snake River Watershed over the most recent 10-year assessment period. Overall, concentrations increased from upstream to downstream on both the Snake and Middle Rivers, with a maximum value of 1.91 mg/L observed at Snake River Site S00-185. Median and maximum concentrations observed on the Snake River ranged from 0.047 to 0.261 mg/L and 0.295 to 1.91 mg/L, respectively. On the Middle River, the median and maximum concentrations ranged from 0.041 to 0.14 mg/L and 0.067 to 0.575 mg/L, respectively. The two most downstream sites on the Snake River (Sites S003-692 and S00-185), located just above and below its confluence with the Middle River, exhibited median concentrations well above the water quality standard of 0.15 mg/L. The maximum TP concentration at all of the Snake River sites and at four of the six Middle River sites also exceeded the water quality standard. Eutrophication criteria had previously been in place for lakes, but the stream criteria are new. These data show that an in-depth analysis of TP data is warranted to determine if impairments exist in the Snake River Watershed.

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Figure 5-14. Chlorophyll a Boxplots and Summary Statistics.

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Figure 5-15. Biochemical Oxygen Demand Boxplots and Summary Statistics.

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68 Figure 5-16. Total Phosphorus Boxplots and Summary Statistics.

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66..0.0 CONCLUSIONS

The Snake River Watershed is located in the Red River of the North Basin in northwestern Minnesota. It drains an area of 611,800 acres, primarily in Marshall County, Minnesota, and is managed by the MSTRWD. The major watercourses include the Snake River, its South Branch, and the Middle River. The watershed also includes an extensive network of drainage ditches, coulees, and, more recently, flood- control impoundments. The Snake River Watershed is within the Red River Valley, which was once at the bottom of Lake Agassiz, and its geomorphology is dominated by the Lake Agassiz Level Lacustrine (Glacial Lake Agassiz), with the exception of the area along the Red River. Soils vary from east to west with much of the eastern areas consisting of sandy, loamy soils and the western third consisting of fine, silty soils. The predominant land cover is agricultural, although wetlands and forested areas exist, particularly in the headwater regions of the Middle River and the Snake River. Because of the poor natural drainage in the former lakebed regions, the watershed has been extensively drained to remove excess water and increase crop production. Primary crops include spring wheat, soybeans, sunflowers, dry beans, and winter wheat.

Six stream segments are listed as impaired within the Snake River Watershed. These 303(d) listings encompass the entire length of both the Snake River (five segments) and Middle River (one segment). The impairments for each stream segment vary and include DO and turbidity on the Middle River and the two most downstream reaches on the Snake River; fish and DO on Snake River’s third reach; fish and turbidity on the Snake River’s fourth reach; and DO on the Snake River’s headwater reach. The water quality analyses performed and summarized in this report confirm these listings.

A long-term, continuous-flow gage is located on the Middle River and, more recently, continuous discharge data have become available at three sites along the Snake River. However, a gage does not exist below the confluence of the Snake and Middle Rivers, which could hinder TMDL development. There is the potential that backwater effects from the Red River would interfere with gaging equipment; in that case, it may be better to use models to estimate loading. The MPCA just completed the intensive watershed monitoring of the Snake River and much of the data were included in the water quality summary. The analysis found measurements of DO, turbidity/TSS, E. coli, pH, and phosphorus that were consistently above existing or proposed standards, although the analyses were more general than what the MPCA requires to determine impairment listings. MPCA’s professional judgment team is currently reviewing the intensive monitoring data, and updated water quality and biological assessments are expected in early 2015.

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77..00 REFERENCES

Aadland, L., S. Jutila, and C. Anderson, 1998. Stream Restoration for Flood Damage Reduction in the Red River, Working Paper #5, prepared by Red River Watershed Management Board, Detroit Lakes, MN. Available online at http://www.rrwmb.org/files/FDRW/TP05.pdf

Anderson, C. and L. Lewis, 1998. Siting and Design of Impoundments for Flood Control in the Red River Basin, Working Paper #4, prepared by Red River Watershed Management Board, Detroit Lakes, MN. Available online at http://www.rrwmb.org/files/FDRW/TP04.pdf

Anderson, C. and A. Kean, 2004. Red River Basin Flood Damage Reduction Framework, Technical Paper No. 11, prepared by the Red River Basin Flood Damage Reduction Work Group, Technical and Scientific Advisory Committee, Detroit, MI. Available online at http://www.rrwmb.org/files/ FDRW/TP11.pdf

Apfelbaum, S. and L. Lewis, 1998. An Overview of the Impacts of Water Level Dynamics (“Bounce”) on Wetlands, Working Paper No. 1, prepared by Red River Watershed Management Board, Detroit Lakes, MN. Available online at http://www.rrwmb.org/files/FDRW/TP01.pdf

Apfelbaum, S., D. Eppich, and J. Solstad, 2004. Wetland Hydrology & Biodiversity in the Red River Basin, Minnesota, Technical Paper No. 12, prepared by the Technical and Scientific Advisory Committee, Detroit Lakes, MI, for the Red River Basin Flood Damage Reduction Work Group, Detroit Lakes, MI. Available online at http://www.rrwmb.org/files/FDRW/TP12.pdf)

Beck, J. and P. Wright-Koll, 2000. Soil Survey of Marshall County, Minnesota Part 1, prepared by National Resources Conservation Service, Washington, DC. Available online at www.nrcs.usda.gov/ Internet/FSE_MANUSCRIPTS/minnesota/MN089/0/Marshall_MN_Part_I.pdf

Bouchard, Jr., R. W., 2014. Development of Biological Criteria for Tiered Aquatic Life Uses, prepared by Minnesota Pollution Control Agency, Environmental Analysis and Outcomes Divisions, St. Paul, MN. Available online at http://www.pca.state.mn.us/index.php/view-document.html?gid=21164

Burke, M., 2015. Initial Hydrology Calibration and Validation of the Snake and Grand Marais Watershed HSPF Models, RSI(RCO)-2354/1-15/58, prepared by RESPEC, Rapid City, SD, for Minnesota Pollution Control Agency, St. Paul, MN, January 30.

Burke, M., 2014. Snake River Watershed and Grand Marais Creek Watershed Model Development, RSI(RCO)-2292/6-14/38, prepared by RESPEC, Rapid City, SD, for Minnesota Pollution Control Agency, St. Paul, MN, June 30.

Christensen, V. G., 2007. Nutrients, Suspended Sediment, and Pesticides in Water of the Red River of the North Basin, Minnesota and North Dakota, 1990–2004, Scientific Investigations Report 2007–5065, prepared by U.S. Geological Survey, Reston, VA. Available online at http://pubs.usgs.gov/sir/ 2007/5065/pdf/SIR20075065.pdf

Cowardin, L. M., V. Carter, F. C. Golet, and E. T. LaRoe, 1979. Classification of Wetlands and Deepwater Habitats of the United States, prepared by U.S. Fish and Wildlife Service, Washington, DC. Available online at http://www.npwrc.usgs.gov/resource/wetlands/classwet/

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Emmons & Olivier Resources, Inc., 2009. Red River Biotic Impairment Assessment, prepared by Emmons & Oliver Resources, Inc., Oakdale, MN, for Minnesota Pollution Control Agency, St. Paul, MN. Available online at http://eorinc.com/documents/RedRiverBioticImpairmentAssessment.pdf

Eppich, D., S. Apfelbaum, and L. Lewis, 1998. Small Wetlands Use for Stormwater Runoff Management in the Red River of the North Basin, Technical Paper No. 2, prepared by Red River Watershed Management Board, Detroit Lakes, MN. Available online at http://www.rrwmb.org/ files/FDRW/TP02.pdf

Eppich, D., M. MacGregor, and A. Kean, 2003. Red River Basin Flood Damage Reduction Project Monitoring Program, Technical Paper No. 9, prepared by Red River Watershed Management Board, Detroit Lakes, MN. Available online at http://www.rrwmb.org/files/FDRW/TP09.pdf

Farnsworth, R. K, E. S. Thompson, and E. L. Peck, 1982. Evaporation Atlas of the Contiguous 48 United States, prepared by Office of Hydrology, National Weather Service, National Oceanic and Atmospheric Administration, Washington, DC.

Gernes, M., L. Lemm, D. Norris, R. Sip, and D. Weirens, 2012. Minnesota Wetland Program Plan: [Prepared in Response to U.S. EPA Guidance], Version 1.0: 2012–2017, prepared by Minnesota Board of Water and Soil Resources, St. Paul, MN, Minnesota Department of Natural Resources, St. Paul, MN, Minnesota Department of Agriculture, St. Paul, MN, and Minnesota Pollution Control Agency, St. Paul, MN, for Minnesota Pollution Control Agency, St. Paul, MN. Available online at http://www.pca.state.mn.us/ index.php/view-document.html?gid=18979

Groshens, T. G., 2007. Red River Basin Stream Survey Report: Snake and Tamarac River Watersheds 2006, prepared by Minnesota Department of Natural Resources, Division of Fish and Wildlife, Bemidji, MN.

Heiskary, S., R. W. Bouchard, and H. Markus, 2013. Minnesota Nutrient Criteria Development for Rivers, wq-sp-08, prepared by Minnesota Pollution Control Agency, Environmental Analysis and Outcomes Division, St. Paul, MN (draft). Available online at http://www.pca.state.mn.us/index.php/view- document.html?gid=14947

Johnson, B., 2003. Basin Strategy: Hydrologic Analysis, Technical Paper No. 10, prepared by the Technical and Scientific Advisory Committee, Detroit Lakes, MI, for the Red River Basin Flood Damage Reduction Work Group, Detroit Lakes, MI. Available online at http://www.rrwmb.org/files/FDRW/TP10.pdf

Johnson, G., 2008. Evaluation of “Paired” Turbidity Measurements From Selected North Shore Streams Using Different Turbidimeters, prepared by Minnesota Pollution Control Agency, Regional Division, Environmental Review and Technical Assistance Section, St. Paul, MN. Available online at http://www.lakesuperiorstreams.org/northshore/poplar/TMDL/docs/TurbidityReports/Poplar_TurbidityTM DL_EvalOfPairedTurbidityMeasurements.pdf

Kurz, B. A., X. Wang, L. de Silva, S. K. Hanson, M. D. Kurz, W. D. Peck, T. K. Simonsen, and E. N. Steadman, 2007. An Evaluation of Basinwide, Distributed Storage in the Red River Basin: the Waffle® Concept, prepared by Energy & Environmental Research Center, University of North Dakota, Grand Forks, ND, for Natural Resources Conservation Service, Bismarck, ND. Available online at http://library.nd.gov/statedocs/UND/WaffleReportNew20100429.pdf

Larson, G., 1998. The Effectiveness of Agricultural Best Management Practices for Runoff Management in the Red River Basin of Minnesota, Technical Paper No. 3, prepared by Red River Watershed Management Board, Detroit Lakes, MN. Available online at http://www.rrwmb.org/files/FDRW/TP03.pdf

RESPEC RSI-2483 71 Snake River Watershed Conditions Report

Lawrence, E., A. R. W. Jackson, and J. M. Jackson, 1998. “Eutrophication,” Longman Dictionary of Environmental Science, Addison Wesley Longman Limited, London, England, pp. 144–145.

Marshall County Water Resources Advisory Committee, 2012. Marshall County Local Water Management Plan 2007–2015. Amended Plan for Years 2012–2015, prepared by Marshall County Water Resources Advisory Committee, Marshall County Water and Land Office, Warren, MN. Available online at http://www.co.marshall.mn.us/marshallcounty/Amended%20LWMP%202012-2015.pdf

McCollor, S. and S. Heiskary, 1993. Selected Water Quality Characteristics of Minimally Impacted Streams From Minnesota’s Seven Ecoregions, prepared by Minnesota Pollution Control Agency, St. Paul, MN.

Middle-Snake-Tamarac Rivers Watershed District, 2009. “Agassiz Valley Water Resource Management,” mstrwd.com, retrieved November 3, 2014, from http://www.mstrwd.com/agassiz-valley- water-resource-management/

Middle-Snake-Tamarac Rivers Watershed District, 2011. Final Ten Year Watershed Management Plan May 2011, prepared by Middle-Snake-Tamarac Rivers Watershed District, Warren, MN. Available online at http://www.mstrwd.com/docs/MSTRWD%20Final%20Plan-May2011.pdf

Middle-Snake-Tamarac Rivers Watershed District, 2013. Middle-Snake-Tamarac Rivers Watershed District 2013 Annual Report, prepared by Middle-Snake-Tamarac Rivers Watershed District, Warren, MN. Available online at http://www.mstrwd.com/wp-content/uploads/ 2013AnnualRptfinalmerged.pdf

Minnesota Department of Health, 2013a. Q & A: General Goals and Requirements of Wellhead Protection, prepared by Minnesota Department of Health, Drinking Water Protection, Source Water Protection Unit, St. Paul, MN, January 10. Available online at http://www.health.state.mn.us/ divs/eh/water/factsheet/whp/qawhp.pdf

Minnesota Department of Health, 2013b. Recommendations and Guidance Pertaining to the Development and Implementation of Source Water Protection Plans for Public Water Supplies Relying on Surface Waters, prepared by Minnesota Department of Health, Source Water Protection Unit, St. Paul, MN. Available online at http://www.health.state.mn.us/divs/eh/water/swp/surfaceguide.pdf

Minnesota Department of Natural Resources, 1997. Minnesota Wetlands Conservation Plan, Version 1.02 1997, prepared by Minnesota Department of Natural Resources, St. Paul, MN. Available online at http://files.dnr.state.mn.us/eco/wetlands/wetland.pdf

Minnesota Department of Natural Resources, 2007. “Groundwater Recharge GIS Metadata,” state.mn.us, retrieved November 14, 2014, from http://www.dnr.state.mn.us/groundwater/ groundwater_recharge_metadata.html#ordering

Minnesota Department of Natural Resources, 2008. “DNR 24K Streams,” state.mn.us, retrieved July 9, 2014, from http://deli.dnr.state.mn.us/metadata/strm_baseln3.html

Minnesota Department of Natural Resources, 2014. “Water Use – Water Appropriations Permit Program,” state/mn.us, retrieved November 5, 2014, from http://www.dnr.state.mn.us/waters/ watermgmt_section/appropriations/wateruse.html

Minnesota Department of Natural Resources, 2015. “Ecological Classification System,” state.mn.us, retrieved November 5, 2014, from http://www.dnr.state.mn.us/ecs/index.html

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Minnesota Legislature, 2014. “Chapter 7050, Waters of the State,”mn.gov, retrieved November 3, 2014, from https://www.revisor.mn.gov/rules/?id=7050

Minnesota Pollution Control Agency, 2006. Lower Otter Tail River Turbidity—Total Maximum Daily Load Report, Water Quality/Impaired Waters #5.02a, prepared by Minnesota Pollution Control Agency, St. Paul, MN. Available online at http://www.pca.state.mn.us/index.php/view-document.html?gid=8016

Minnesota Pollution Control Agency, 2007. Statement of Need and Reasonableness Book III of III, prepared by the Minnesota Pollution Control Agency, St. Paul, MN. Available online at http://www.pca.state.mn.us/index.php/view-document.html?gid=7270

Minnesota Pollution Control Agency, 2014. Guidance Manual for Assessing the Quality of Minnesota Surface Waters for Determination of Impairment: 305(b) Report and 303(d) List, wq-iw1-04, prepared by Minnesota Pollution Control Agency, St. Paul, MN. Available online at http://www.pca.state.mn.us/index.php/view-document.html?gid=16988

Natural Resources Conservation Service, 2012. Rapid Watershed Assessment: Snake River (MN) HUC: 09020309, prepared by Natural Resources Conservation Service, Warren, MN. Available online at http://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/nrcs142p2_022747.pdf

Northwest Minnesota Soil & Water Conservation Districts, 2014. “What is a SWCD,” nwmnswcd.org, retrieved November 3, 2014, from http://www.maswcd.org/What_is_an_SWCD/ what_is_an_swcd.htm

Omernik, J. M., 1987. “Ecoregions of the Conterminous United States,” Annals of the Association of American Geographers, Vol. 77, No. 1, pp. 118-125.

Paakh, B., W. Goeken, and D. Halvorson, 2006. State of the Red River of the North, Assessment of the 2003 and 2004 Water Quality Data for the Red River and its Major Minnesota Tributaries, prepared by Minnesota Pollution Control Agency, Detroit Lakes, MN, and Red River Watershed Management Board, Detroit Lakes, MN. Available online at http://www.pca.state.mn.us/index.php/view-document.html? gid=6039

Pomme de Terre River Association, 2011. Turbidity TMDL Assessment for the Pomme de Terre River Report, wq-iw7-18e, prepared by Pomme de Terre River Association, Morris, MN, for Minnesota Pollution Control Agency, St. Paul, MN. Available online at http://www.pca.state.mn.us/index.php/view- document.html?gid=16258

RTI International, 2007. Poplar River Turbidity Total Maximum Daily Load: Evaluation of Existing Data, prepared by RTI International, Research Triangle Park, NC, for U.S. Environmental Protection Agency Region 5, Chicago, IL. Available online at http://www.lakesuperiorstreams.org/ northshore/poplar/TMDL/docs/TurbidityReports/Poplar_TurbidityTMDL_EvalOfExistingData.pdf

Solstad, J., 1998. Watershed Modeling of Various Flood Damage Reduction Strategies, Technical Paper No. 6, prepared by Red River Watershed Management Board, Detroit Lakes, MN. Available online at http://www.rrwmb.org/files/FDRW/TP06.pdf

Stoner, J. D., D. L. Lorenz, R. M. Goldstein, M. E. Brigham, and T. K. Cowdery, 1998. Water Quality in the Red River of the North Basin, Minnesota, North Dakota, and South Dakota, 1992–95, U.S. Geological Survey Circular 1169, prepared by U.S. Geological Survey, Reston, VA. Available online at http://pubs.usgs.gov/circ/circ1169/circ1169.pdf

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Technical and Scientific Advisory Committee, 1998. Implementation of a Flood Damage Reduction Strategy in the Red River Basin, Technical Paper No. 8, prepared by Red River Watershed Management Board, Detroit Lakes, MN. Available online at http://www.rrwmb.org/files/FDRW/TP08.pdf

Tornes, L. H., 2005. Water Quality of Streams in the Red River of the North Basin, Minnesota, North Dakota, and South Dakota, 1970–2001, Scientific Investigations Report 2005–5095, prepared by U.S. Geological Survey, Reston, VA. Available online at http://pubs.usgs.gov/sir/2005/5095/pdf/report.pdf

U.S. Environmental Protection Agency, 2010. Primary Distinguishing Characteristics of Level III Ecoregions of the Continental United States, prepared by U.S. Environmental Protection Agency, Washington, DC. Available online at ftp://ftp.epa.gov/wed/ecoregions/us/Eco_Level_III_ descriptions.doc

U.S. Geological Survey, 2012. “National Hydrography Dataset,” usgs.gov, retrieved November 3, 2014, from http://nhd.usgs.gov/data.html

U.S. Fish and Wildlife Service, 2000. “Agassiz National Wildlife Refuge,” fws.gov, retrieved October 14, 2014, from http://www.fws.gov/uploadedFiles/AgassizWeb.pdf

U.S. Fish and Wildlife Service, 2011. National Wetlands Inventory Program: 2010 Annual Report, Tande, G. F. and J. M. Michaelson (eds.), prepared by U.S. Fish and Wildlife Service, Division of Habitat and Resource Conservation, Arlington, VA.

Van Offelen, H. and A. Kean, 2005. On-Channel Storage in the Red River Basin—Guidelines for Site Selection, Design, and Operation, Technical Paper No. 13, prepared by the Technical and Scientific Advisory Committee, Detroit Lakes, MN, for the Red River Basin Flood Damage Reduction Work Group, Detroit Lakes, MN. Available online at http://www.rrwmb.org/files/FDRW/TP13.pdf

Woodbury, L. and R. St. Germain, 1998. Flood Frequency Based Design, Technical Paper No. 7, prepared by Red River Watershed Management Board, Detroit Lakes, MN. Available online at http://www.rrwmb.org/files/FDRW/TP07.pdf

Yoder, C. O., 2012. Framework and Implementation Recommendations for Tiered Aquatic Life Uses: Minnesota Rivers and Streams, prepared by Midwest Biodiversity Institute, Center for Applied Bioassessment and Biocriteria, Columbus, OH, for Minnesota Pollution Control Agency, St. Paul, MN. Available online at http://www.pca.state.mn.us/index.php/view-document.html?gid=18309

RESPEC RSI-2483 74 Snake River Watershed Conditions Report

A APPENDIX A: SOCIOECONOMIC DATA

RESPEC RSI-2483 A-1 Snake River Watershed Conditions Report

Table A-1. 2012 Census Estimates

Population Change, Median Median Household High School Employed by Unit of Population, Subdivision 2000–2012 Age, 2012 Income, 2012 Graduate Dominant Industry Dominant Industry Government 2012 (%) (years) ($) (%) (%) Townships Agder 103 –4.6 49.8 73,750 92.0 Manufacturing 20.55 Big Woods 107 35.4 28.1 50,000 93.4 Education, health care, social assistance 27.08 Bloomer 80 –13.0 44.8 60,250 92.5 Construction, agriculture, forestry, fishing and hunting, mining 26.19 Boxville 46 48.4 48.8 48,750 100.0 Agriculture, forestry, fishing and hunting, mining 31.58 Cedar 69 –26.6 55.8 45,000 85.0 Manufacturing 30.56 Comstock 113 –16.3 58.4 57,917 86.5 Agriculture, forestry, fishing and hunting, mining 28.57 East Valley 28 –37.8 58.3 53,750 88.5 Arts, entertainment, recreation, accommodation, food, public administration 30.77 Excel 292 4.3 49.8 67,500 95.0 Education, health care, social assistance 23.16 Fork 10 –28.6 65.5 48,750 50.0 Agriculture, forestry, fishing and hunting, mining 100.00 Holt 136 –7.5 45.4 43,125 97.0 Wholesale trade 34.29 McCrea 275 10.0 40.3 70,833 95.0 Construction 14.63 Moose River 31 10.7 50.8 32,500 100.0 Manufacturing 40.00 Moylan 116 –9.4 48.0 57,500 82.6 Agriculture, forestry, fishing and hunting, mining 33.33 New Folden 220 11.7 43.7 58,750 85.3 Construction 28.00 New Solum 333 6.4 32.8 65,938 98.6 Wholesale trade 16.16 Oak Park 131 –20.6 46.8 78,750 88.5 Retail trade 27.78 Parker 17 –70.2 52.8 85,625 100.0 Agriculture, forestry, fishing and hunting, mining 60.00 Vega 124 –20.0 52.3 51,964 100.0 Manufacturing 28.17 Veldt 52 –7.1 44.7 41,667 90.9 Manufacturing 59.09 Viking 157 8.3 34.9 50,000 91.6 Education, health care, social assistance 20.99 Warrenton 93 0.0 40.7 72,500 100.0 Agriculture, forestry, fishing and hunting, mining 29.51 Municipalities Alvarado 328 –11.6 34.5 47,917 85.9 Education, health care, social assistance 25.88 Argyle 535 –18.4 53.3 40,625 80.4 Education, health care, social assistance 18.18 Grygla 229 0.4 48.3 43,750 86.0 Manufacturing 28.03 Holt 76 –14.6 41.5 63,750 81.8 Education, health care, social assistance, retail trade, manufacturing 16.13 Newfolden 401 10.8 33.5 48,333 87.5 Manufacturing 25.25 Oslo 328 –5.5 38.2 48,462 85.6 Retail trade 20.65 Viking 116 26.1 27.5 31,563 93.4 Education, health care, social assistance 42.86 Warren 1,791 6.7 38.7 47,406 80.1 Education, health care, social assistance 31.00 Snake River Watershed 6,414 0.12 NA NA 89.1 Education, health care, social assistance 22.90

Source: Economic Profile System—Human Dimensions, 2014

RESPEC RSI-2483 A-2 Snake River Watershed Conditions Report

B APPENDIX B: ADDITIONAL FLOW ANALYSIS FIGURES

Monthly box-whisker plots were created for all four of the discharge gages within the Snake River Watershed to seasonality. Plots are presented in order from upstream to downstream.

RESPEC RSI-2483 B-1

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2 Figure B-1. Monthly Box-Whisker Plots for Minnesota Department of Natural Resources Discharge Gage 68032002.

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3 Figure B-2. Monthly Box-Whisker Plots for Minnesota Department of Natural Resources Discharge Gage 68031002.

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4 Figure B-3. Monthly Box-Whisker Plots for Minnesota Department of Natural Resources Discharge Gage 68006001.

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5 Figure B-4. Monthly Box-Whisker Plots for Minnesota Department of Natural Resources Discharge Gage 68017001.

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C APPENDIX C: ADDITIONAL WATER QUALITY ANALYSIS FIGURES

RESPEC RSI-2483 C-1 Snake River Watershed Conditions Report

APPENDIX C: ADDITIONAL WATER RSI

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C.1 ASSESSMENT PERIOD

Additional figures were created for additional water quality constituents for the most recent 10-year assessment period.

C.1.1 Additional Nutrient Species

Box-whisker plots were created to other nutrient concentrations that do not have an associated specific standard, but these are of interest because they can impact the ability to meet other water quality targets, such as eutrophication and dissolved oxygen (DO). Figures C-1 through C-4 show the most recent 10-year assessment period for orthophosphate, inorganic nitrogen, nitrate, and kjeldahl nitrogen.

C.1.2 Fecal Coliform

Before the adoption of E. coli standards, the bacterial water quality targets were for fecal coliform. The former standards required that the monthly geomean of five or more observations was below 200 organisms/100 mL, or that a single sample concentration was below 400 or 2,000 organisms/100 mL, depending on the water’s designated use. The boxplot for E. Coli is illustrated in Figure C-5.

C.2 ENTIRE PERIOD OF RECORD

Figures were created for the entire period of record of both the constituents presented in the report figures for trace metals, which typically did not have sufficient data during the assessment period to be included in the analysis and other constituents of interest, including conductivity, organic carbon, sulfate

(SO4), total coliform, and total dissolved solids (TDS).

C.2.1 Report Figures

Figures C-6 though C-17 contain box-whisker plots for the entire period of record for chloride, ammonia, DO, temperature, pH, turbidity, transparency, total suspended solids (TSS), E. coli, chlorophyll a, biochemical oxygen demand (BOD), and total phosphorus.

C.2.2 Trace Metals

Figures C-18 through C-27 contain box-whisker plots for the entire period of record for aluminum, arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, and silver.

RESPEC RSI-2483 C-2

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3 Figure C-1. Orthophosphate for Upstream to Downstream Sites.

RESPEC RSI

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4 Figure C-2. Inorganic Nitrogen for Upstream to Downstream Sites.

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5 Figure C-3. Nitrate for Upstream to Downstream Sites.

RESPEC RSI

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6 Figure C-4. Total Kjeldahl Nitrogen for Upstream to Downstream Sites.

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Figure C-5. Fecal Coliform for Upstream to Downstream Sites.

RESPEC RSI-2483 C-7

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8 Figure C-6. Chloride for Upstream to Downstream Sites.

RESPEC RSI

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9 Figure C-7. Ammonia for Upstream to Downstream Sites.

RESPEC RSI

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10 Figure C-8. Dissolved Oxygen for Upstream to Downstream Sites.

RESPEC RSI

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11 Figure C-9. Temperature for Upstream to Downstream Sites.

RESPEC RSI

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12 Figure C-10. pH for Upstream to Downstream Sites.

RESPEC RSI

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13 Figure C-11. Turbidity for Upstream to Downstream Sites.

RESPEC RSI

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14 Figure C-12. Transparency for Upstream to Downstream Sites.

RESPEC RSI

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15 Figure C-13. Total Suspended Solids for Upstream to Downstream Sites.

RESPEC RSI

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Snake River Watershed Snake Conditio River Watershed ns Reportns

16 Figure C-14. E. coli for Upstream to Downstream Sites.

RESPEC RSI

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17 Figure C-15. Chlorophyll a for Upstream to Downstream Sites.

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Figure C-16. Biochemical Oxygen Demand for Upstream to Downstream Sites.

RESPEC RSI-2483 C-18

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19 Figure C-17. Total Phosphorus for Upstream to Downstream Sites.

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Figure C-18. Aluminum for Upstream to Downstream Sites.

RESPEC RSI-2483 C-20 Snake River Watershed Conditions Report

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Figure C-19. Arsenic for Upstream to Downstream Sites.

RESPEC RSI-2483 C-21 Snake River Watershed Conditions Report

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Figure C-20. Cadmium for Upstream to Downstream Sites.

RESPEC RSI-2483 C-22 Snake River Watershed Conditions Report

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Figure C-21. Chromium for Upstream to Downstream Sites.

RESPEC RSI-2483 C-23 Snake River Watershed Conditions Report

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Figure C-22. Copper for Upstream to Downstream Sites.

RESPEC RSI-2483 C-24 Snake River Watershed Conditions Report

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Figure C-23. Lead for Upstream to Downstream Sites.

RESPEC RSI-2483 C-25 Snake River Watershed Conditions Report

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Figure C-24. Mercury for Upstream to Downstream Sites.

RESPEC RSI-2483 C-26 Snake River Watershed Conditions Report

RSI-2417-14-068

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Figure C-25. Nickel for Upstream to Downstream Sites.

RESPEC RSI-2483 C-27 Snake River Watershed Conditions Report

RSI-2417-14-069

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Figure C-26. Selenium for Upstream to Downstream Sites.

RESPEC RSI-2483 C-28 Snake River Watershed Conditions Report

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Figure C-27. Silver for Upstream to Downstream Sites.

RESPEC RSI-2483 C-29 Snake River Watershed Conditions Report

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Figure C-28. Zinc for Upstream to Downstream Sites.

C.2.3 Other Constituents

Figures C-29 through C-34 contain box-whisker plots for the entire period of record for TP, organic carbon, SO4, total coliform, and TDS.

RESPEC RSI-2483 C-30

RESPEC RSI

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31 Figure C-29. Total Phosphorus for Upstream to Downstream Sites (Page 1 of 2).

RESPEC RSI

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32 Figure C-29. Total Phosphorus for Upstream to Downstream Sites (Page 2 of 2).

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Figure C-30. Organic Carbon for Upstream to Downstream Sites.

RESPEC RSI-2483 C-33

RESPEC RSI

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34 Figure C-31. Total Sulfate for Upstream to Downstream Sites (Page 1 of 2).

RESPEC RSI

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35 Figure C-31. Total Sulfate for Upstream to Downstream Sites (Page 2 of 2).

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Figure C-32. Total Coliform for Upstream to Downstream Sites.

RESPEC RSI-2483 C-36

RESPEC RSI

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37 Figure C-33. Total Dissolved Solids for Upstream to Downstream Sites.