Step 2: Characterize Your Watershed
Once you’ve established your partnerships, the next step in your watershed planning effort will be to characterize the watershed so that you can get a better understanding of the impacts in the watershed, the causes and sources of the impacts, and to quantify pollutant loads. After you characterize the watershed you will then have the foundation needed to identify and select management strategies to bring about improvements.
Define the Scope of Your Planning Effort
To ensure that your watershed planning effort remains focused, effective and efficient, defining the scope of the effort is critical. The term scope is used to describe the boundaries of a program or project, which can be defined in terms of space (the area included in the watershed plan) or other parameters. It is important to define the scope of your watershed planning effort as not only the geographic area to be addressed but also the number of issues of concern and the types (and breadth) of the goals you want to attain.
After you’ve defined the scope, one of the first activities you will need to undertake when characterizing the watershed is to talk with stakeholders to identify their issues of concern. These issues will help to shape the goals of the plan and to determine what types of data are needed. As a project manager you might think you already know the problems, such as not meeting designated uses for swimming and fishing. The issues of concern are different in that these are the issues that are important to the community. For example, stakeholders frequently list trash in the streams as an issue. Other groups might be interested in protecting stream buffers, wetlands and other critical resources.
Gathering Existing Data
Unfortunately, we don’t have a natural system barometer to hang outside our window that gives us a direct measure of existing conditions. Instead, we must choose multiple indicators (chemical, biological and physical) that can help us indirectly gauge overall system integrity.
In general, five broad categories of data are used to adequately characterize the watershed:
- Physical and natural features—watershed boundaries, hydrology, topography, soils, climate, habitat, wildlife.
- Land use and population characteristics—land use and land cover, existing management practices, demographics.
- Water body and watershed conditions—water quality standards, 305 (b) report, 303(d) list, TMDL reports, source water assessments.
- Pollutant sources—point sources, nonpoint sources.
- Water body monitoring data—water quality and flow, biology, geomorphology.
When collecting data, be sure to collect data on both the potential natural pollutant sources and potential human sources. Both pollutant source types can influence pollutant loading.