Appendix A: Glossary of Terms

This appendix provides a list of terms useful in communicating effectively and ensuring consistency among California based Watershed Assessment Framework (WAF) Valuation projects. The terms and definitions provided below come from a combination of reports and background documents from both state and federal efforts towards developing ecological condition reporting frameworks for monitoring watershed condition and health.[1]

Note 1. Developed by Fraser Shilling (UC Davis) based on the index/indicator literature and feedback from Jeff Sharp (Napa County) and Mike Antos (Los Angeles San Gabriel Rivers Watershed Council).

Watershed Assessment Framework

The Watershed Assessment Framework (WAF) is in an evaluation framework developed for use at the scale of identified watershed boundaries. The geographical scope of the assessment framework varies, and is based upon the watershed area being evaluated. The concept and use of the WAF was developed by the USEPA’s Science Advisory Board and has been adapted to meet watershed monitoring needs and performance measures identified in the California Watershed Management Strategic Action Plan.

The framework provides a scientifically defensible approach for aggregating and assessing a wide variety of environmental, economic and social data. The framework can be used to assist in linking the condition of a watershed’s air, water, land, biota, and social structures into a broad framework termed ecosystem condition. the sum total of the physical, chemical, social and biological components of the watershed and how they interact and change over time. The WAF includes evaluation of economic and social conditions at the watershed scale and is a way of integrating consideration of environment, economics, and social conditions in watersheds. The WAF acknowledges that humans and their activities are integral parts of watersheds and their ecosystems.

Goals & Objectives

“Goals and Objectives. Ideally, environmental management programs begin with a process to develop goals and objectives that articulate the desired ecosystem conditions that will result from the program(s).” (USEPA SAB Report)

Goals describe desired outcomes for a watershed or similar place, through a particular project or program in a stated timeframe. In the case of the WAF, groups could set goals for the watershed, in which case they would be describing the desired outcomes for the watershed in some stated timeframe.

Objectives are the tactics to the goals’ strategies. They describe actions that can be taken to implement or reach goals. Objectives for watersheds can be defined as actions that help reach desired outcomes for particular aspects of watershed condition.

Figure 1. Watershed Assessment Framework



Sometimes organizations want to develop a comprehensive understanding of environmental or social health and express that as a single score, which is a composite of several or many indicators. This composite is usually called an index. In terms of the WAF, you could imagine scores for indicators within each essential attribute being composited into an overall attribute score for health assessment based upon a set of identified goals. In this case, the attribute is functioning as an index. The WAF is also an index, composed of the 8 attributes and component indicators, though a single index score for the WAF may be only generally meaningful.

Essential Watershed Attributes

“The EEAs and their component categories and subcategories can be used as a checklist to help design environmental management and assessment programs and as a guide for aggregating and organizing information.” (USEPA SAB Report)

The essential watershed attributes (EWA) provide a way to categorize environmental and social processes to facilitate understanding and reporting of condition. The 8 essential attributes identified in the WAF valuation projects is a means to categorize various attributes that describe a watershed and are described below.

Landscape Condition. The extent, composition, and pattern or structure of (non-human) habitats in a landscape.

Biotic Condition. The condition or viability of communities, populations, and individual biota (i.e., at the scale of individual habitat types).

Ecological Processes. Metabolic function of ecosystems - energy flow, element cycling, and the production, consumption, and decomposition of organic matter at the ecosystem or landscape level.

Social Condition. The examination of the organization and development of human social life within the watershed, including measurements of community and social patterns, and behavior of individuals and groups.

Economic Condition. Measures of community economic well-being and of the production, distribution, and consumption of goods and services within a watershed, including the valuation and of non-market resources that provide individual and community utility.

Chemical and Physical Characteristics. Physical parameters and concentrations of chemical substances present in the environment/watershed (water, air, soil, sediment).

Hydrology/Geomorphology. Characteristics that reflect the dynamic interplay of surface and groundwater flows and the land forms within the watershed.

Natural Disturbance. The historical and/or contemporary function of discrete and usually recurrent disturbances, which may be physical, chemical, or biological in nature, that shape watershed ecosystems.


A category is a class of similar concepts, ideas, or things within in an organized and rule-based system to discriminate among classes where the discrimination is based on apparent differences among the categorized objects. EWAs are pseudo-categories in that they contain groups of similar indicators, but are not completely discreet and overlap each other. The EWAs often include sub-categories. Categories are one way to organize information in an overall condition index, like the WAF, where the categories and sub-categories are used to classify related indicators.


Ecological Indicators (also called ecological endpoints) are measurable characteristics related to the structure, composition, or functioning of ecological systems. Multiple indicators may be associated with each subcategory in the EEA hierarchy.” (USEPA SAB Report)

Indicators (the backbone of the WAF process) provide a way to collect information about a condition and to report and compare condition over time. Indicators in the WAF are organized within EWAs and are based on metrics or measures of condition, though sometimes indicators and metrics are the same thing.


Measures. The measures are the specific monitoring variables that are measured in the field and aggregated into one or more ecological indicators.” (USEPA SAB Report)

Metrics/Measures are the building blocks of indicators and thus the foundation of a condition assessment system (e.g., the WAF). Examples of metrics and measures include DO concentration, proportion of successful nests (i.e., produce young) per season for a particular bird species, and fire return interval for a particular plant community within a study area. Each of these measures might fit into an indicator composed of one or more metrics (e.g., “fire dynamics”) that in turn is categorized into an EWA (e.g., natural disturbance) or EWA sub-attribute (e.g., fire).

Figure 2. Example use of Categories, Indicators and Metrics in a report card format