The Importance of the USAP

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. Support planning and design teams in identifying and prioritizing the highest functioning system with the lowest long-term maintenance effort, given the watershed or stream context.

USAP provides a structure that embraces the complexities of 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). 

USAP Overview

MHFD developed USAP to improve planning and stream management by using integrated methods and robust data collection and evaluation techniques. USAP has several defining features that make it well-suited for our urban environment. Among these features are:

• A multi-scale approach that can be applied from a watershed-scale for planning to a stream-reach scale for design alternatives.
• A focus on the physical conditions of urban streams and on the forms and processes that create them.
• A framework that recognizes community values associated and how they impact stream management.
• A tailored approach to assessing each stream in its unique context to guide realistic and effective management.

USAP leverages repeatable methods, including desktop analysis and field data collection. Results can be interpreted at the watershed, stream corridor, and stream reach scales. The data and results we generate help promote an understanding of the Five Elements of stream function - community values, hydrology, hydraulics, geomorphology, and vegetation. 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.

USAP’s Steps and Associated Tasks

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.

USAP’s Indicators and Metrics

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).