This map shows the three multimetric index layers created as part of the California Integrated Assessment of Watershed Health:
- Relative Watershed Condition Index
- Relative Stream Health Index
- Relative Watershed Vulnerability Index
More information on the project can be found here.
The overarching goal of the Assessment is to characterize
the relative health of watersheds across the state for the purpose of guiding future watershed protection
initiatives. The Assessment synthesizes disparate data sources and types to depict current watershed
condition and stream condition throughout California. It is framed around the recognition that the biological,
chemical, and physical health of a stream are fundamentally connected to one another and to the
maintenance of natural watershed processes. The Assessment further recognizes that California’s watersheds
are dynamic, ever-changing systems and characterizes the vulnerability of watershed health to future
degradation. By integrating information on multiple ecological attributes at several spatial and temporal
scales, a systems perspective on watershed health is provided.
Readers are asked to consider the following points regarding the scope of the Assessment as they review
methods and interpret results:
- The term watershed health can have several connotations. Its use here refers to the holistic
condition of freshwater ecosystems within a watershed. The condition of terrestrial, estuarine,
coastal, and marine ecosystems are not explicitly analyzed and results should not be used to infer
the condition of these ecosystem types.
- The Assessment characterizes relative watershed health throughout the state using a collection of
indicators that focus on the natural attributes of a watershed and its freshwater streams. No
statement on the absolute condition of any watershed or water body is made and results do not
reflect the influence of factors not considered for analysis.
- Watershed health data generated by the Assessment are intended to support a screening-level
assessment of protection priorities across broad geographic areas (e.g., statewide or within the
jurisdiction of a Regional Water Control Board). The data should not supplant in-depth, site-specific
evidence of protection priorities. Conclusions drawn for smaller-sized areas should be validated with
site-specific information.