MHFD uses the USAP to determine stream function within an urban stream context and to evaluate planning priorities and project alternatives to ensure we are implementing the best projects to protect people, property, and our environment. The goal of the USAP is two-fold:
1. Provide repeatable, consistent, and defensible methods to assess the physical condition of urban streams.
2. Provide a tool that supports planning and design teams in identifying and prioritizing the highest functioning system(s) with the lowest long-term maintenance effort(s), given the watershed or stream context.
USAP provides a structure that embraces the complexities inherent in urban streams by integrating community values (such as health and wellness, public safety, and recreation) with physical elements (including flow regime, geomorphic processes, and vegetation structure). These features allow USAP to be a consistent approach to evaluating urban watersheds and streams.
MHFD developed USAP to improve planning and stream management in our urban systems by using integrated methods and robust data collection and evaluation techniques. USAP has several defining features that make it well-suited for in our urban environment. Among these features are:
USAP leverages repeatable methods (desktop analysis, rapid and intensive field data collection) and easily interpretable results through data inventory and evaluation at the watershed, stream corridor, and reach scales.
The data and results we generate help promote an understanding of community values, as well as the hydrologic, hydraulic, geomorphic, and vegetation processes foundational to urban streams (i.e., the Five Elements). In addition to describing the stream’s current community values and physical condition, the results also identify the hazard risks, problem areas, and maintenance requirements, which provide a baseline for future improvements. Finally, USAP allows us to document the positive improvements of our project following implementation.
The roadmap to USAP’s assessment framework can be subdivided into two sections: what is assessed and how it is assessed–in the context of the Five Elements. Thus, implementing USAP across the watershed, corridor, or reach scales, requires applying methods separated into three steps as shown below.
1a. Data discovery and literature review
1b. Geospatial mapping
1c. Prioritize data, determine data gaps
1d. Context and stressors
1e. Stream character via reach types
2a. Define indicators
2b. Choose metrics, measurements, and methods
2c. Identify scoring guidelines (functional characteristics)
2d. Perform assessment (collect and evaluate data)
2e. Condition interpretation tables and photos/mapping
2f. Metric and indicator scoring
3a. Stream condition diagnosis
3b. Limiting factors and stressors analysis
3c. Problem/reach identification
3d. Mapping and data visualization
USAP includes 16 indicators that influence stream condition, which together cover the spectrum of USAP’s five elements. For each indicator, various metrics, detailed in the resource file below, measure features or attributes that identify the functional status of a particular indicator (e.g., fully functional, functional, not functional).