SI-4 (3/8/05 version)
Watershed-Based Options To Address Stream Integrity Impairment: Overview

"Successful stream stewardship requires sound engineering and scientific principles, together with an understanding and appreciation of the ecology of the stream and its interaction with the landscape" (Ward and Trimble, 2003).

As this quote states, assessing and managing streams for integrity is a multi-disciplinary task.

Table 1 illustrates that the type of stream assessment (and the associated type of expertise) that is needed depends on the scale of the stream system being studied, the scientific and economic questions that need to be answered, and ultimately, the stream management objectives. There are many other reasons for local management of stream morphology (e.g., flood control, drainage, erosion control, etc.). However, this section of the NPS Plan focuses on watershed-based, sustainable stream channel management to achieve attainment of aquatic life use water quality standards. Further detail on each of the steps outlined is available by clicking on the hyperlinks within Table 1.

Because, use of the process below is necessary to develop more specific environmental targets for specific stream reaches, this section of the plan does not present a list of statewide targets as is done in the chemical integrity section. Existing habitat targets, developed prior to the process outlined in Table 1 are summarized elsewhere. As more local watershed action plans are completed, it is expected that proposed actions to address stream integrity will be based on use of the process below. Therefore, by 2010, Ohio should have a more comprehensive list of watershed-based targets to support stream integrity at a level that will result in aquatic life use attainment.

Table 1. Designing Sustainable Stream Channel Systems to Achieve and Maintain Ecological Integrity*

  Step Scale Of Indicators Needed Question/Purpose Associated Design Question
Step 1 Watershed Wide Where is the channel in its process of evolution? What is the associated distribution of fish communities given the stream morphology characteristics of the watershed?
Step 2
  • Watershed Wide
  • Study Reaches and Contiguous Reaches - upstream and down
What is the disturbance? What is the scale and level of effect of the PAST and PRESENT disturbances on the channel form and aquatic communities?
Step 3 Watershed and Reach What future disturbances are likely to occur? What are the potential disturbance types and locations and what are their predicted impacts on channel form and aquatic communities?
Step 4 Reach or reaches What are the channel / community dynamics today? Given the current stream morphology characteristics, what is the ecological/biological role of the study reach within the watershed and contiguous reaches?
Step 5
  • Study reach and contiguous or reference reaches
  • Site Level
What is the stream morphology and community response to disturbance What is the predicted channel form and community /habitat response to future disturbances.
Step 6
  • Study reach and contiguous or reference reaches
  • Site Level
Determine ultimate channel form What fish/macroinvertebrate community, species assemblages, and habitat are necessary for water quality attainment. What do we prefer or have to be satisfied with?
Step 7
  • Study reach
  • Site Level
Is intervention feasible? What is the potential impact (costs and benefits) of the ultimate channel form on the habitat and fish/macroinvertebrate community?
Step 8
  • Study reach
  • Site Level
Define intervention options What are the habitat requirements for keystone species?
Step 9
  • Study reach
  • Sites
Complete design Development of an integrated and ecologically sound (species requirements are documented) final design.
* Modified from Training Notes, Aquatic Biology and Stream Systems, General, "Natural Channel Systems, Biological/Ecological Design Process, A companion component to the Geomorphic and Engineering Design Processes (pp. 706 and 707 of 934 on pdf version at http://www.trentu.ca/wsc/PDFfiles/natproceeds.pdf)