Assess Biological, Hydrological, and Geomorphological Conditions
Watershed health can be evaluated by assessing several specific parameters, including watershed-scale and reach-scale properties and functions. To be eligible for grant funding from CWCB’s Watershed Restoration Program, assessments must include (at a minimum) aquatic biota, flow regime, and fluvial geomorphology at a reach scale.
Example watershed-scale parameters
Example reach-scale parameters
Depending on the purpose and scope determined by local stakeholders, assessments employ different methodologies to evaluate stream health. The comprehensiveness of the data varies depending on the core questions addressed by the SMP, ranging from less precise (general, often anecdotal or third-party information) to more precise (data-driven, quantitative metrics).
Click on the table below to see a description and examples of Level 1, 2, and 3 data types.
Description: Coarse level of investigation designed to provide a general estimation of ecological integrity
Example Methodologies:
- anecdotal evidence, direct observations
- review of published literature and reports focused on streamflow, erosion, water quality, and aquatic life
- desktop assessments of aerial imagery
- “windshield” surveys
Description: Scientists and other experts use best professional judgement to assess qualitative observations and data gathered during field visits
Example Methodologies:
- rapid (1-2 day) functional condition assessments of stream reaches conducted by a team of geomorphologists, hydrologists, engineers, and/or riparian ecologists
Description: Quantitative methodologies that use data to generate numerical or statistical metrics of ecological condition
Example Methodologies:
- 1D/2D hydraulic modeling
- biological sampling
- riparian transects
- aquatic habitat surveying
- fluvial hazard zone mapping
River Health Assessments
River health assessments may also include additional important watershed-scale components for a more holistic, watershed-wide evaluation. Fluvial Hazard Zone (FHZ) mapping and forest health are being considered in an increasing number of SMP/IWMPs.