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Aquatic habitat indicators and their application to water quality objectives within the Clean Water Act. EPA-910-R-99-014 Item Info

The objective of this paper is to evaluate the application of aquatic habitat variables to water quality objectives under the authority of the Clean Water Act (CWA). The project is limited to freshwater, lotic aquatic habitats in the Pacific Northwest and Alaska with an emphasis on salmonid habitat. Habitat variables were placed into one of the following categories - flow regime, habitat space, channel structure, substrate quality, streambank condition, riparian condition, temperature regime, and habitat access. Candidate habitat variables were evaluated for their relevance to the biotic community, responsiveness to human impacts, applicability to target landscapes, and measurement reliability. The most critical obstacles for use of habitat variables a the regional levels (state specific water quality criteria for Region 10 EPA) are the quantification of biological effect and the unreliability of the measurement system. Inherent variability and unreliable data quality preclude the use of numeric values for habitat variables as compliance indicators in statewide water quality criteria. Rather, habitat variables should be used as diagnostic indicators of beneficial use attainment and pollution control performance, and should be developed and calibrated at local or ecoregional scales as stratified by landscape and stream characteristics. Currently only a few habitat variables meet the evaluation criteria established by the authors for use under CWA authority, specifically large woody debris, pool frequency, and residual pool depth. It is recognized that this limited set of variables will not satisfy the ecological habitat requirements needed to protect cold water biota. Recommendations to increase the applicability of habitat indicators to CWA objectives include an interagency (and international) effort to evaluate landscape classification of aquatic areas, identify and measure reference area condition at ecoregional scales, and develop a systematic approach of habitat indicator quantification. In the interim the authors recommend a re-examination of the narrative water quality standards in EPA Region 10 to provide more specificity in regards to salmonid habitat protection. Water quality standards should also specify the process whereby numeric criteria can be established at the local or ecoregional scale.

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Title:
Aquatic habitat indicators and their application to water quality objectives within the Clean Water Act. EPA-910-R-99-014
Authors:
Bauer, Stephen B.; Ralph, Stephen C.
Date Created (ISO Standard):
1999-07
Description:
The objective of this paper is to evaluate the application of aquatic habitat variables to water quality objectives under the authority of the Clean Water Act (CWA). The project is limited to freshwater, lotic aquatic habitats in the Pacific Northwest and Alaska with an emphasis on salmonid habitat. Habitat variables were placed into one of the following categories - flow regime, habitat space, channel structure, substrate quality, streambank condition, riparian condition, temperature regime, and habitat access. Candidate habitat variables were evaluated for their relevance to the biotic community, responsiveness to human impacts, applicability to target landscapes, and measurement reliability. The most critical obstacles for use of habitat variables a the regional levels (state specific water quality criteria for Region 10 EPA) are the quantification of biological effect and the unreliability of the measurement system. Inherent variability and unreliable data quality preclude the use of numeric values for habitat variables as compliance indicators in statewide water quality criteria. Rather, habitat variables should be used as diagnostic indicators of beneficial use attainment and pollution control performance, and should be developed and calibrated at local or ecoregional scales as stratified by landscape and stream characteristics. Currently only a few habitat variables meet the evaluation criteria established by the authors for use under CWA authority, specifically large woody debris, pool frequency, and residual pool depth. It is recognized that this limited set of variables will not satisfy the ecological habitat requirements needed to protect cold water biota. Recommendations to increase the applicability of habitat indicators to CWA objectives include an interagency (and international) effort to evaluate landscape classification of aquatic areas, identify and measure reference area condition at ecoregional scales, and develop a systematic approach of habitat indicator quantification. In the interim the authors recommend a re-examination of the narrative water quality standards in EPA Region 10 to provide more specificity in regards to salmonid habitat protection. Water quality standards should also specify the process whereby numeric criteria can be established at the local or ecoregional scale.
Subjects:
Water quality standards Water quality criteria Indicators Aquatic habitats Salmonid
IWRRI number:
199902
Rights:
Rights to the digital resource are held by the University of Idaho. http://www.uidaho.edu/
Publisher:
US Environmental Protection Agency, Region 10, Seattle WA
Contributing Institution:
University of Idaho
Type:
Text
Format:
application/pdf
Cataloger:
KIT
Date Digitized:
2017-09-26

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Preferred Citation:
"Aquatic habitat indicators and their application to water quality objectives within the Clean Water Act. EPA-910-R-99-014", Idaho Waters Digital Library, University of Idaho Library Digital Collections, https://www.lib.uidaho.edu/digital/iwdl/items/iwdl-199902.html
Rights
Rights:
Rights to the digital resource are held by the University of Idaho. http://www.uidaho.edu/
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