The Watershed Health Assessment Framework (WHAF) provides an organized approach for exploring and analyzing the complexity of natural and human systems. The Use Examples show ways to use the map, health scores and other information to systematically examine watershed systems.
The WHAF Process Guide is another resource that provides an applied example of the WHAF tools in an analysis of the Crow Wing River Watershed.
Set Scale–Watershed Boundaries
- Map Your Watershed Boundaries
- Why Are Watershed Boundaries Important?
- Use Example: The Pine River Watershed–Major Watershed Boundary
- Use Example: Managing Mussels in the St. Croix River-Connecting Upstream and Downstream.
Watershed boundaries are a challenge to understand and can be difficult to visualize or map. Use WHAF's predefined boundaries and symbols to help address this challenge. You can display different watershed boundaries for any location in Minnesota in a couple steps:
- Open the map above in a new browser window.
- Click anywhere in Minnesota to display the watershed boundaries for that location.
- Use the ‘Set Scale’ tool (upper right) to select different symbols and zoom levels to explore the different watershed boundaries.
There are different symbols shown for each type of watershed boundary:
- Pink outline: Catchment; local land area that sends surface water to the point you selected.
- Light blue fill: Upstream Catchments; the 'true' watershed for surface water flow.
- White outline: Major watershed boundary; the administrative boundary for managing watersheds.
- Dark blue fill: Downstream Catchments; the flow path for surface water leaving the catchment.
- Mask: Major River Basin; the large river system connected to your location.
Boundaries are important because they help you systematically think about each different scale. They also help you decide what to include and what to leave out of your evaluation.
Before selecting a boundary (size of area or length of time), you should think about what ‘process’ you hope to influence.
Sediment delivery: Where is sediment coming from? How big is the land area contributing surface water flow?
Land Cover: What are the local and regional land cover types? How much is vegetated, paved or cultivated? Are there important or sensitive natural resource communities?
Water flow and volume: Where is water coming from? How much of the connected river system is of concern?
Contaminant sources: Where are the contaminants coming from? Are there sources/types that are of particular interest?
Information delivery: What key audiences might need to alter their management of land and water resources? Where are the opportunities to work with communities and policy makers?
With these questions in mind, review the nested watershed scales and decide which of these scales should be used to begin your investigation of watershed health.
You may also need to consider other types of boundaries. There may be legal jurisdictions such as cities, counties, tribal lands and zoning authorities. There may also be time constraints such as funding cycles that are a mismatch with the rate of measurable watershed change.
It is important to periodically revisit your selected boundaries to ensure you are not missing important inputs occurring at other scales.
You are preparing for an annual meeting with landowners that live on Whitefish Lake near the center of the Pine River Major Watershed. Click to open this WHAF map.
While the interest is in the local lake, you decide to summarize information at the major watershed boundary. There are a number of reasons why this is an appropriate scale to review the conditions influencing Whitefish Lake.
- The major watershed is a 'true watershed’, this scale will connect water quality, biology and land use.
- Whitefish Lake connects to both the Pine River watershed (upstream) and an important chain of lakes downstream.
- Conditions throughout the major watershed will be of interest for managing the lake.
- There is an active effort to cooperatively manage the Pine River Major Watershed by both state agencies and citizens.
After investigating and collecting some insights at this scale, your next step is to check other scales:
- Zoom out to the Upper Mississippi River Basin, look for conditions beyond the major watershed that may influence health and risk levels in this watershed.
- Zoom in to find local conditions that may directly impact the health of Whitefish Lake.
In this example, a manager is exploring conditions that influence the mussel community near Folsum Island, in the St. Croix River at Interstate State Park. Investigating the health of an aquatic community in a river system should include looking upstream and downstream of the site.
This is particularly important when managing mussels. Mussel community health is directly tied to the presence of barriers to fish passage. The life cycle of mussels requires the presence of a specific host fish. If the host fish species is blocked, the mussel cannot reproduce.
In this example, the hydropower dam upstream of Folsum Island will prevent the passage of fish species from the upstream part of river system to the lower river. That barrier will influence the distribution of the mussel populations.
Another influence on mussel community health is the presence of excessive sediment covering the streambed makes it difficult for sensitive mussel species to survive and thrive.
Land cover conditions throughout the basin may have an impact on the river and this aquatic community. The land cover charts show the way the land is being used at different scales. The map below shows the St. Croix Basin and related land charts. The land cover charts summarize national data so they give an accurate snapshot of the St. Croix Basin land cover even though a large portion of the basin extends into Wisconsin.
Open this map