Tools for Assessing Stream Quality

• About the Monitoring/Assessment Section
• Potential Watershed Indicator Profile Sheets
• Monitoring Factors to Consider
• Rapid Assessment Methods
• Watershed Treatment Model
• Hydraulic and Hydrologic Assessment Tools and Models

 

Environmental Indicators

Environmental indicators are select parameters and indices which can be used to characterize overall conditions in the receiving water and provide benchmarks for assessing the success of watershed management efforts. A profile sheet is provided for each of the 26 environmental indicators that includes a brief description of the indicator; a discussion of the indicator utility; a review of indicator advantages and disadvantages; an indicator case study; implementation costs (in 1995 dollars); and references. Click on the indicators in Table 1 to view the profile sheets.

Table 1. Potential Watershed Indicators To view these profile sheets, you need the Adobe Acrobat Reader. Don't have it? Download it for free here:
Water quality indicators: Water quality pollutant constituent monitoring Toxicity testing Non-point source loadings Exceedance frequencies of water quality standards Sediment contamination Human health criteria Water quality indicators cost comparisons	Physical and hydrological indicators: Stream widening/downcutting Physical habitat quality Impacted dry weather flows Increased flooding frequency Stream temperature monitoring Physical and hydrological indicators cost comparisons
Biological indicators: Fish assemblage analysis Macro-invertebrate assemblage Single species indicator Composite indicators Other biological indicators Biological indicators cost comparisons	Social indicators: Public attitude surveys Industrial/commercial pollution prevention Public involvement and monitoring User perception Social indicators cost comparisons
Programmatic indicators: Number of illicit connections identified/corrected Number of BMP's installed, inspected, and maintained Permitting and compliance Growth and development Programmatic indicators cost comparisons	Site indicators: BMP performance monitoring Industrial site compliance monitoring

(Source: Adapted from Claytor, 1996)

The identification of appropriate indicators for monitoring programs should be based upon watershed or sub-watershed management goals and/or categories, regional and site-specific considerations, and available resources. Some examples of indicators and methods appropriate for differing watershed management categories are shown in Table 2.

Table 2. Watershed Indicators Appropriate for Different Management Categories
Subwatershed Management Category	Suggested Indicators
Sensitive Stream	Single species biomonitoring (e.g., salmon, trout) Impervious cover measurements Aquatic habitat and the stream geometry
Impacted Stream	Impervious cover measurements Aquatic habitat and stream geometry Biological indicators such as macroinvertebrate and fish populations
Non-Supporting Stream	Single species biomonitoring Selected chemical constituents such as metals, hydrocarbons, and other toxins Trash and debris surveys Public attitude surveys
Restorable Stream	Impervious cover measurements Aquatic habitat and stream geometry Biological indicators such as macroinvertebrate and fish populations Trash and debris surveys Public attitude surveys Programmatic indicators
Urban Lake	Impervious cover measurements Monitoring for selected chemical constituents, such as phosphorus Water clarity or turbidity Bacteria monitoring or beach closures Programmatic indicators
Water Supply Reservoir	Impervious cover measurement Monitoring for selected chemical constituents such as bacteria and other pathogens Water clarity or turbidity
Coastal/Estuarine	Biological indicators such as macroinvertebrate and fish populations Monitoring for selected chemical constituents Bacteria monitoring, shellfish beds, or beach closures
Aquifer Protection	Impervious cover measurement Biological indicators such as amphibians, macroinvertebrates and fish Selected chemical constituents such as metals, hydrocarbons, and trace metals

Regardless of the specific indicators selected, it is important to utilize scientifically reliable assessment techniques, quality controls, and valid sampling protocols to ensure that results are repeatable, consistent, and compatible with other data collection efforts. The rapid assessment methods presented in this section incorporate these necessary elements.

This first step in utilizing environmental indicators is to establish a baseline or current condition. This baseline condition will be used as the basis by which to judge the success of future watershed management actions. This baseline condition then needs to be compared to a reference condition. The reference condition represents the best attainable condition for that indicator in a "least disturbed" location. For the reference condition to be appropriate, the reference condition must be from an area of similar natural environmental conditions, in other words, within the same geologic province, ecoregion, and of the same drainage area and/or stream order to reflect what the baseline condition would be in the absence of disturbance.

Some environmental indicators require that monitoring stations be established and field sampling conducted, while others can be derived from existing programmatic resources and records. Indicator monitoring may require several years of sampling to establish trends and assess program effectiveness. For those indicators that require field sampling, there are several key factors to consider when establishing long term field monitoring stations. Poorly sited stations may provide no useful information, or require years of additional data collection to provide the required information. Table 3 highlights some key factors to consider when locating field monitoring stations.

Table 3. Key Factors to Look at When Locating Indicator Monitoring Stations
Locational Consideration	Notes
Station should be representative of subwatershed characteristics	Consider available resources (funds and staff) to determine the number of stations per subwatershed. Remember that the assessment of management measures will depend on results of monitoring and subwatershed classification will depend on conditions of resource.
Stations should be located downstream of proposed future activities	In order to assess the implementation of land use management techniques, BMPs or other subwatershed protection measures, monitoring stations must be carefully located in order to compare before and after conditions.
Stations should be located based on a statistical randomness criteria (where appropriate)	When using the monitoring data to compare multiple subwatersheds, the location of stations should be consistent across the spectrum of subwatersheds being analyzed. Two commonly used techniques are to locate stations at the confluence of second order streams or just upstream of road crossings.
Stations should be relatively easy to access	Some stations will need to be revisited tens to hundreds of times. Managers need to consider ease of access and time in locating stations.
Stations not likely to be compromised by vandals or storm damage	Stations that involve installing expensive or sophisticated monitoring equipment should be located in a "secure" area and consideration should be given to what will happen to equipment during a major storm. Equipment may need to be housed in a durable monitoring "house" or have remote sensors or samplers to collect data.

Rapid Assessment Methods

Indicator monitoring often involves complex data collection and analysis techniques that can require substantial investments of time and resources. Local communities often lack the resources and expertise to undertake these complex tasks, yet need accurate information on watershed and stream conditions. This section highlights some of the rapid assessment methods that can be undertaken with a minimum resource commitment while producing timely, useable information. Click on the titles of the methods described below to learn more.

• The Impervious Cover Model - As the percentage of impervious cover increases in a subwatershed, stream quality tends to diminish. This simple classification system allows a community to predict current and future stream quality based on the assessment of impervious cover.
• The Simple Method - This model allows stormwater runoff pollutant loads to be calculated with a minimum need for data collection. The Simple Method estimates pollutant loads for chemical constituents as a product of annual runoff and pollutant concentrations.
• Rapid Stream Assessment Technique (RSAT) - The Rapid Stream Assessment Technique was developed by John Galli at the Metropolitan Washington Council of Governments. This assessment methods allows an investigator to rapidly assess stream conditions and identify stream restoration needs. The information is provided in a downloadable PDF format.
  
• Rapid Bioassessment Protocols (RBP) - The Rapid Bioassessment Protocols are a series of methodologies developed by the U.S. Environmental Protection Agency for assessing water quality, habitat, and biology in streams and rivers. Click on the link below to go to EPA's Rapid Bioassessment web page: http://www.epa.gov/owow/monitoring/rbp/
• Stream Visual Assessment Protocol (SVAP) - The USDA Natural Resource Conservation Service (NRCS) developed the Stream Visual Assessment Protocol as a basic assessment technique that does not require extensive biological expertise or training. This assessment is intended to be conducted in cooperation with landowners as an educational/outreach tool. Click on the link below to go to the USDA NRCS water quality assessment web page: http://www.wcc.nrcs.usda.gov/water/quality/frame/wqam/

About the Monitoring/Assessment Section

Need to characterize conditions in your watershed, but don't have much time or money to do so? Check out some simple and fast methods to get a handle on pollution and stream habitat problems in your watershed.