Center for Coastal Resources Management

Resources: York River Water Budget - Methods

Three main methods based on Jowett 1997 are used for determining instream flow requirements:

1. hydrologic (or historic)

2. hydraulic

3. biological

The goal is to maintain stream flow ecosystem with maximized:

1. proportion of flow,

2. wetted perimeter

3. physical habitat

Assumptions: a linear relationship between river flow and threshold minimum flow for aquatic life.

Summary of the differences between the main methods of setting minimum flow standards (adapted from Jowett 1997)

Various types of minimum in-stream flow methods:

• Hydrologic Methods

• Hydraulic Methods

• Biological Methods

• Comparing methods in rivers and estuaries