One of the most critical steps in protecting your stream is finding out what is happening in the watershed. Conducting a watershed assessment will help you identify existing problems in your stream, anticipate future threats, and create opportunities to promote the value of your local stream. It also can be a fun and rewarding activity for the members of your organization. Exhaustive research may not be necessary or feasible for your organization, so do not be overwhelmed by the numerous possibilities identified here. Start collecting information now and consider watershed assessment an ongoing process that grows with your organization.

Set Goals for Your Assessment

As with most activities, it is useful to spend time thinking about why you want to do it before starting. A little planning will ensure that you focus on collecting the information you need and that your participants are satisfied that the efforts are serving a purpose. Each organization will likely choose some different goals for its watershed assessment, and you are encouraged to be creative and develop your own. A few examples are provided here to get you started.

Possible Goals for a Watershed Assessment

  1. To understand and document the ecological state of streams and other natural resources of the watershed. (In other words, which areas of the watershed are healthy? Which are polluted? Which areas should be
    priorities for additional protection?)
  2. To identify potential causes of pollution, including very localized impacts.
  3. To prepare for effective participation in Clean Water Act programs and other programs designed to protect and restore the watershed.
  4. To identify priority areas for a river clean up.
  5. To identify the most critical areas for restoration efforts.
  6. To identify recreational needs and promote recreational resources of the watershed.
  7. To raise local awareness for protecting local streams.
  8. To build and strengthen commitment of our organization’s membership through an important, fun, eye-opening, and rewarding activity.

Get Started! Gather Available Information

Just as goals will vary among watershed groups, each organization will include different information in its assessment, based on different interests of the participants. This section offers ideas that you may choose from and add to as you study your watershed. Because there is a lot of information out there and you’ll want to involve several members in this activity, you may want to divide these tasks among several teams.

Get a good topographic map of the watershed. The Illinois Atlas & Gazetteer (DeLorme) is a great starting place for locating the boundaries of your watershed, and it is likely that at least one of your members has a copy in her car. If you’d like more detail, you can buy USGS maps at various scales. These can be found in good map stores, or can be ordered from the USGS online store .

Draw the watershed boundary on the map. By connecting all of the highest elevations around the streams of your watershed, you can identify all of the land area and potential pollution sources that drain into the streams in your watershed.

Identify unique natural resources in your watershed. Several Illinois Dept. of Natural Resources documents, such as Critical Trends Assessment Program (CTAP) reports, are useful in identifying healthy waters and lands. You can also search the Illinois Natural History Survey collections and databases to find plants and animals that have been collected in your watershed, dating back to the 1800s. The fish, crustacean, insect, and mussel collection databases will allow search queries by stream, and these are extremely useful tools. Talk to local conservationists to learn about other areas of local ecological interest.

Collect available water quality data. USEPA’s STORET system is a repository for water quality data. Additional volunteer monitoring data may have been collected through Illinois RiverWatch program. Check the RiverWatch website to find out if volunteer data is available in your watershed.

Identify the impaired waters in your watershed. Using the state’s 303(d) list, identify which streams in your watershed have been identified by Illinois EPA as impaired (note causes of impairment and sources). Note that less than 20% of the state’s streams are assessed for the purposes of this report. Therefore, it is not a comprehensive list of impairments, but it is a good starting point. Contact Illinois EPA to find out if these streams are scheduled to have “TMDLs” (water quality restoration plans) developed.

Identify regulated pollution sources. Using the permit compliance system, locate all point source discharges. Illinois EPA’s Water Quality Mapping Tool also contains information on pollution sources and identifies the location on a map. Note the type of facility, the pollutants discharged in your watershed, and the amount of pollution discharged. Find out when these permits are due to expire. Review other items in this toolkit to prepare to participate in the permit renewal process.

Identify towns and counties that are wholly or partially within the watershed. Note whether these towns are expected to grow significantly in coming years. Find out what local protections these local governments have adopted such as watershed protection ordinances. These could include stream buffer ordinances, erosion and sediment control ordinances, etc.

Explore Your Watershed

In getting to know your watershed, there is no substitute for muddy boots. A lot of information about the health of the streams is not yet documented anywhere except on the land and waters themselves. Bring your watershed map, a notebook, and a camera for a drive/walk/canoe around the watershed. If you have a GPS, bring it along to note precise locations associated with your observations. Be respectful of property owners; obtain permission before crossing private property. Most participants won’t need to be reminded to have fun, but encourage them to bring along binoculars, fishing rods, etc.

Note the physical characteristics of the streams where you can get to them. Is there a vegetated buffer on either side of the stream? Are the banks eroding? Are there deeper pool areas and shallow riffle areas? Is there a lot of trash? Is the water clear, brown, green? Take photographs of both the good and the bad conditions that you find. These photographs may also be useful in outreach and education efforts, most importantly, slide shows for public audiences.

Note the adjacent land uses. What areas of the watershed are urban or suburban? Which areas are agricultural? Are there pasture lands? If so, is there evidence of livestock entering the creeks? Are there a number of landowners planting row crops to the edges of the stream? Do nearby lands have gullies or other evidence of severe erosion? Are there any adjacent industrial or mining developments?

Identify public areas along streams (state parks, local parks, forest preserve). Note good wildlife watching areas, fishing spots, canoe launches, and hiking opportunities.

Begin collecting your own water quality data around the watershed. Check the RiverWatch website to find out when the macroinvertebrate monitoring training sessions are offered. Contact Prairie Rivers Network if you are interested in collecting water chemistry information through the Illinois Stream Team. See the Illinois Stream Team section of this toolkit for more information about this program.
Review your goals to identify what other information you need to find in order to achieve your mission of protecting your streams. Contact Prairie Rivers Network for assistance or to share suggestions for future watershed assessments.

Examples of helpful websites:

IEPA Online Mapping Tool

USGS online store (maps)

CTAP reports

INHS Collections

STORET system

RiverWatch – National Great Rivers Research and Education Center

Illinois 303(d) list