Stream Channel Monitoring

Prince George’s County (the County) monitors stream channels to help assess stream channel erosion and stability. Understanding stream channel erosion and relative stability is important in water quality protection efforts. Accelerated streambank erosion and channel instability can incise the stream valley, impact water quality, and degrade aquatic habitats by introducing excessive sediment loads. Excessive sediment loads increase turbidity, which often reduces dissolved oxygen levels due to the effects on light penetration and aquatic photosynthesis. Additionally, sediment loads can accumulate in streambeds, degrading habitat used by aquatic organisms. Sediments can also introduce other pollutants into waters because they can contain heavy metals, pesticides, or nutrients originating from terrestrial activities such as farming or land development.

The County recently established a long-term stream channel stability monitoring program to collect geomorphic data and assess stream stability. The program supports County efforts to improve stream conditions, reduce sediment loads, and identify stream reaches impacted by excessive stormwater runoff. A comprehensive set of measurements is used to evaluate channel form and stability. The results provide valuable insights into the relative condition of stream channels and enable comparisons across watersheds and landscapes.

For a more in-depth analysis of the County’s monitoring program that evaluates erosion rates and sediment production in streams, and factors potentially influencing them, please check out the following article: Landscape changes and watershed erosion in Prince George's County, Maryland.

Dashboard Instructions

Features

Use the filter bar, located at the top right of the screen, to refine data based on water quality constituent(s), subwatershed(s), and year(s) collected. Upon clicking the themed filter box, select one or more option from the drop-down menu. Data displayed in the map and tables will then update based on selection. Please note:
- Filters from multiple themes can be selected at the same time.
- Due to the nature of the datasets, biological and stream monitoring data has been separated from the rest of the water quality constituents and is located in its own filter box (to the right of "Water Quality Constituent(s)).
Use the vertical menu bar in the upper right of the map to customize the map.
- To view the full menu and descriptions of the icons, click on the Expand icon (double arrows) at the bottom of the vertical menu (the last icon).
- To view the list of symbols and their meanings, click on the Legend icon (bullet points).
- To change the preset view, click on the Bookmarks icon (bookmark).
- To view the different map layers, click on the Layers icon (stacked boxes). Hidden layers will have crossed-out eye icons, whereas visible layers will not have an icon present.
- To change the basemap, click on the Basemap icon (four small squares) and select from the options.
To move around the map, click and hold the cursor on the map, then drag it to see different areas. To zoom in, double click on area of interest on the map. There are also Zoom in (plus symbol)/Zoom out icons (minus symbol) located at the bottom right of the map.
To reset the entire dashboard to its preset layers and features, including the map, click the Reset icon (circular arrow) located in the lower right-hand corner of the dashboard.

How to use

The map and tables (dashboard) show all available data for all water quality constituents. To select the constituents discussed above, click on the "Biological & Stream Monitoring" filter and select the relevant one from the dropdown options. The dashboard should update automatically to show relevant monitoring stations (Station IDs).

To explore the data using the map:

Zoom in on a monitoring station and click on it.
A pop up text box will appear showing a data summary for each constituent.
Use the left/right arrow icons at the top left of the pop up box to scroll through all records. Please note: Arrows are only present when the selected Station ID has data for more than one filtered constituent.
To zoom in further on the station from the pop up box, click the magnifying glass icon in the top right corner (below the Station ID name).
Zooming in on the map will also filter the list of Station IDs in the table on the top right of the dashboard to show only those stations visible in the map extent.

To explore the data using the tables:

Select the "Stream Cross-Sections" tab at the bottom of lower table.