• Using the Map
• Interpreting Graphs in the Water Quality Dashboard
• Interpreting Support Status
• Accessing and Viewing Total Maximum Daily Load (TMDL) Reports and Other Documents

Using the Map

• Click on a lake or stream to view summary graphs of recent water quality data (Water Quality Dashboard), access a list of links to individual monitoring stations where data can be viewed and downloaded (Monitoring Data), view water quality reports and project information (Projects and Reports), and see water quality assessments from the latest South Dakota Integrated Report for Surface Water Quality Assessment (Support Status).
• Dots on the map represent water quality monitoring stations. Click on a station to view tables of recent data from that station for select water quality parameters (parameters are types of water quality data). For an explanation of water quality parameters, click here. The table will not display if there is no recent data. All data for all parameters regardless of age can be downloaded by from each station into a Microsoft Excel spreadsheet by clicking the Download All Parameters (Excel) button.
• Search for stations, streams, lakes, and other features using the search box and drop down menu in the upper left corner of the map.
• Open the legend menu by clicking on the left-most icon in the top right corner of the map. The legend displays the symbols for sample collection station types (Citizens Monitoring, Chemistry, and Fish Flesh Contaminant). It also displays symbols for lakes and streams that are supporting all beneficial uses and therefore meeting water quality standards in blue. All lakes and streams that are not supporting all beneficial uses, and therefore not meeting water quality standards, are shown in red. Lake regions are displayed by colors that represent each region.
• Open the layer menu by clicking on the middle icon in the top right corner of the map. The layer menu allows the user to turn on or off various sources of information that are displayed on the map. Stations, streams, lakes, roads, and lake regions can be turned on or off in this menu. Lake regions were produced by grouping lakes into regions based on similarities between lakes, allowing the user to compare the data of their lake of interest to other similar lakes in the same region by presenting statistical values including the lake and regional mean (average), median, maximum (max), and minimum (min) in the Water Quality Dashboard.

Interpreting Graphs in the Water Quality Dashboard

Graphs in the Water Quality Dashboard present sample data for each assessment unit. Assessment units are lakes or segments of rivers and streams that are used to classify waters of the state for the purpose of assessing their water quality. Graphs include lines displaying water quality standards where applicable and, for lakes only, regional moving averages for select parameters. These lines can be turned on and off by checking the box associated with the line for the standard or regional moving average. More than one standard line may exist for water quality parameters where there is more than one threshold. E. coli standards include a threshold for single samples and a separate threshold for the geometric mean of a minimum of five samples collected in a 30 day period. Total Suspended Solids standards, in most cases, also have two thresholds - one for single samples and another separate threshold for the average of 5 samples collected within a 30 day period.

Interpreting Support Status

The beneficial use support status for each waterbody is presented in the “Support Status” tab. All waters in South Dakota are designated beneficial uses, which are uses for the waterbody deemed to be appropriate to the waterbody’s attributes. Examples of beneficial uses are Domestic Water Supply (drinking water), Irrigation, Limited Contact Recreation Waters (e.g. boating, fishing, kayaking), Immersion Recreation Waters (swimming, water skiing), and various beneficial uses designed to protect fisheries (e.g. Warmwater Marginal Fish Life Propagation, Coldwater Permanent Fish Life Propagation). Each beneficial use also assigns water quality standards for parameters that are important to protecting the beneficial use. For example, the Immersion Recreation beneficial use assigns a standard for E. coli to protect people recreating in the water from getting sick from bacteria, and the beneficial uses for fisheries assign standards for dissolved oxygen to protect fish from low oxygen levels that would cause fish kills. If all water quality standards associated with the beneficial uses assigned to a waterbody are being met, it is considered to be in full support of its beneficial uses. If one or more of the standards for a beneficial use is not being met, that waterbody is not in full support of its beneficial uses. Beneficial use support status is assessed every 2 years and is presented to the public in the South Dakota Integrated Report for Surface Water Quality Assessment.

Accessing and Viewing Total Maximum Daily Load (TMDL) Reports and Other Documents

Waters that are not in full support of their beneficial uses require a Total Maximum Daily Load (TMDL) report under the federal Clean Water Act. These reports detail the sources of pollution for the parameter of concern, and develop recommendations for how much of a pollutant can be in a waterbody while still meeting water quality standards and supporting its beneficial uses. TMDL reports are presented as links in the Projects and Reports tab. Other water quality documents are also available, such as watershed assessment project reports, watershed improvement project reports, and watershed strategic plans. These documents for each waterbody are linked in the Projects and Reports tab.