• Introduction
• Step 1
• Step 2
• Step 3
• Step 4
• Step 5
• Step 6
• Step 7

Well-organized data are the foundation of any assessment. Key organizing elements take shape in the screening design step. These include:

Establish IDs. In Step 1, you selected the targeted units for your screening assessment - usually watersheds at one or more scales. You now need a unique identifier for every individual unit you plan to assess. Organized systems of IDs probably already exist and should be used if possible. For example, the Watershed Boundary Dataset (WBD) Exit is a widely-used national source of drainage-based hydrologic units (HUCs) at several scales, each with a common ID system already established. The value of using existing ID schemes is not only to use terms familiar to others, but also because many of the measurements needed for recovery potential indicators, such as water quality monitoring or land cover data, may have already been compiled and referenced to these IDs.  The Watershed Index Online (WSIO) and the EPA’s EnviroAtlas both have compiled hundreds of watershed indicators at the commonly-used HUC12 watershed scale, and these are publicly available.

Select and compile candidate indicators. Above all, Recovery Potential Screening (RPS) depends on selecting relevant watershed indicators because indicators provide the basis for comparison. A critical planning task in every RPS project is to decide what watershed indicators are most relevant to the screening purpose. Think of indicator selection in two stages: first, you will build a menu of all potentially relevant indicators, and second, you will select a smaller, more specific set of indicators when you are ready to use them in a screening run. In step 2, you are only building the menu of indicators you might use at one time or another.  Your RPS project may be capable of developing new indicators, or might be limited to using existing indicator data only. If relying on existing data, you should screen watersheds at the HUC12 scale (approximately 35 square miles on average), and your indicator selections could then draw from the several hundred HUC12-scale indicators already compiled nationally as part of the Watershed Index Online (WSIO).

Substantial information on recovery potential indicators is available through this website in the form of a literature database, available indicators lists and definitions, and indicator-specific reference sheets. The indicator selection worksheet (PDF) (2 pp, 134 K), which contains example indicators, may be helpful to jump-start the process of discussing and identifying the factors most relevant to restorability and to your screening purpose in particular. This worksheet or other materials from the RPS Indicators section can help you enlist your own group's expert judgement. This is best done in an informal group discussion involving those most familiar with the area's water bodies, impairment types, and restoration track record to date. The workgroup should feel free to identify, modify or add key factors that are not listed, and do not hesitate to select relatively large numbers of indicators initially. Consider this stage of indicator selection more inclusive than exclusive - capture all the potentially relevant indicators now and reduce to manageable numbers later when more narrowly-defined screening runs are carried out.

The candidate indicators are organized in three major categories - ecological, stressor and social - based on the three main mechanisms by which natural and human-made driving factors influence watershed condition and recovery potential. Ecological indicators measure those properties that are related to current watershed condition and the capacity to maintain or reestablish natural structure and processes. Stressor indicators are associated with reduced natural function due to the negative impacts of pollutants and other stressors. Social indicators address a broad array of community, regulatory, economic and behavioral measures that often have a profound influence on restoration success, independent of the environmental factors. Although there is much flexibility in the choice of individual indicators, it is crucial to use some indicators in each of these three categories.

Selecting indicators should assemble a collection of recovery-relevant factors that each provide a different 'piece of the puzzle' within each of the three categories. Subcategories of the ecological, stressor and social indicator categories are provided below to encourage a diverse selection of indicators. It may not be possible to obtain data on all of the factors you'd like to measure, or to have an indicator from every subcategory, but every effort should be made to use indicators that are not all related to the same subcategory (e.g., ecological indicator selection should include more than just different measurements of watershed land cover.)

Subcategories for ecological indicator selection include (see Ecological Indicators for examples of each):

• Ecological history;
• Watershed natural land cover;
• Flow dynamics;
• Channel, corridor and near-shore stability;
• Biotic community integrity; and
• Aquatic connectivity.

Subcategories for stressor indicator selection include (see Stressor Indicators for examples of each):

• Watershed-level disturbance;
• Corridor or near-shore disturbance;
• Biotic or climatic risks;
• Severity of pollutant loading;
• Hydrologic alteration; and
• Legacy of past, trajectory of future land use.

Subcategories for social context indicator selection include (see Social Indicators for examples of each): 

• Watershed-level leadership, organization and involvement;
• Protective ownership or regulation;
• Level of information and planning;
• Restoration cost, difficulty, or complexity;
• Socio-economic considerations; and
• Relevance to human health and beneficial uses.

A fourth indicator category, called Base Indicators, contains parameters such as watershed ID, name, total area and other useful reference information.  Base Indicators do not affect the index scoring, so this category is generally used for value-neutral properties of the watershed. However, the Base category is sometimes used to store indicators that may be used in different categories, depending on the screening purpose. Such ‘ambiguous’ indicators can be moved from the Base into another indicator category and used in index development according to the specific screening needs. 

After reviewing lists and definitions of available indicators, RPS users often decide that they have additional data and can compile more new indicators that will make their screening results better. Although it can be time-consuming to compile additional indicators, local or state-specific data sources often include key parameters (such as bioassessment datasets) that haven’t been possible to compile nationally. General information on Developing New RPS Indicators should be consulted to be sure new indicators will be fully consistent with existing data.

Review and refine preferred indicators. As your project takes shape, you may significantly modify your initial assumptions about indicators. Several candidate indicators may be abandoned due to insufficient data sources, quality or consistency, or new ones may be added from existing sources or created from other data sources as part of your project. This final stage of step two is a reexamination of all the candidate indicators and measurement alternatives that you would like to have available for screening. Have your workgroup review and discuss these indicators, add new metrics or remove less relevant or redundant metrics.  Also, review and evaluate data quality of every indicator in this process.  

As you refine your list to include indicators of more consistent quality and relevance, numbers per category and subcategory remain important. There should be no fewer than three indicators in each of the major categories for a given screening. Generally, using five to ten indicators in each of the three categories will be desirable for a single screening, so consider that when finalizing your larger selection at this point. Having many more indicators available ‘on the menu’ is not problematic at this stage as it will enable you to explore alternative combinations of indicators in an iterative screening, or to address more screening purposes, when you begin the screening runs.