The federal Clean Water Act requires states to conduct a biennial comprehensive analysis of state waters to determine if water bodies meet state water quality standards and thus support beneficial uses, or if additional pollution controls are needed. DEQ meets this requirement by preparing Idaho's Integrated Report.
After a public comment period, DEQ submits the Integrated Report to the U.S. Environmental Protection Agency (EPA) for approval and makes it available to the public. The report serves as a guide for developing and implementing water quality improvement plans (total maximum daily loads) to protect water quality and achieve federal and state water quality standards. An Integrated Report must be approved by EPA before it can be used by a state to guide its management decisions.
Idaho's most recent approved version is its 2014 Integrated Report (2014 map viewer). The 2014 report was submitted to EPA for review on February 15, 2017, and approved by EPA on June 5, 2017 (EPA Approval Letter). The 2016 Integrated Report was submitted to EPA on November 9, 2018 and is currently awaiting approval. Although the 2016 Integrated Report is summarized here and the document is available for download, the 2014 Integrated Report should be used to guide decision-making until the 2016 report is approved by EPA.
There are several ways to access information in Idaho’s 2016 Integrated Report:
- Read the background and summary information provided below.
- Download the report document, which includes background, methods, and state-wide summary information. The report also includes appendices that describe the status of all water bodies in the state.
- View a pdf map of all water bodies in the state (32 x 42 inches)
- Use an interactive map to search for water body-specific results
Purposes of the Integrated Report
The Integrated Report serves the following three functions:
- It satisfies the requirements of Clean Water Act sections 305(b), 303(d), and 314 by listing the current conditions of all state waters (required by §305(b)), including publicly owned lakes (required by §314), and lists waters that are impaired and need a total maximum daily load (TMDL) (required by §303(d)).
- It informs the public about the status of state waters, enabling interested parties to comment on the status of all Idaho’s waters and provide relevant data.
- It provides a unique opportunity for the public to understand the overall status of Idaho’s water quality and gain a better understanding of how DEQ is maintaining, improving, and protecting Idaho’s waters.
Categorization of Waters in the 2016 Integrated Report
Highlights of the 2016 Integrated Report
- Based on existing and readily available water quality data and information assessed for the 2016 Integrated Report, 33% of stream/river miles and 6% of lake acres are fully supporting state water quality standards, 36% of streams and 55% of lakes are not fully supporting water quality standards, and 31% of streams and 39% of lakes have not been assessed.
- DEQ delisted 129 AU-cause combinations from Categories 4 and 5 during the 2016 Integrated Report cycle.
- The Idaho Wadeable Stream Survey found that over 70% of Idaho’s wadeable streams are fully supporting their cold water aquatic life beneficial use.
- Restoration efforts have resulted in water quality improvement. These nonpoint source program success stories are highlighted in Appendix A of the report. Sediment reductions have restored the cold water aquatic life beneficial use in Jordan Creek in northern Idaho, and agricultural best management practices and restoration projects have restored the recreational beneficial use for two assessment units in Deep Creek in northwestern Idaho.
- An updated assessment guidance document, Water Body Assessment Guidance (WBAG) was used to assess water bodies in the 2016 Integrated Report. Prior reports relied on the 2002 edition of the WBAG. While the general approach for assessments did not change with the revised WBAG, much of the underlying framework was altered. Some of those changes include a revised site classification system, revised reference sites and reference conditions, new metrics and indices, and a revised condition rating threshold to determine beneficial use support status.
- A description of Idaho’s new Category 1 definition, adopted for this reporting cycle. DEQ updated the definition of the land use requirements for Category 1 inclusion due to promulgation of the 2008 Idaho Roadless Rule by the US Department of Agriculture. This rule changed the boundaries of US Forest Service roadless areas within Idaho and how those areas are managed. As such, roadless area classifications that DEQ previously used to identify Category 1 assessment units have been superseded by five management themes outlined in the 2008 Idaho Roadless Rule.
Summary of Water Quality Support Status
Streams and Rivers
Lakes and Reservoirs
|Support Status and Category||Number of
aAssessment unit-cause combinations