Water Quality

Every two years, DEQ is required to assess water quality and report to the U.S. Environmental Protection Agency on the condition of Oregon's waters. DEQ prepares an Integrated Report that meets the requirements of the federal Clean Water Act for Sections 305(b) and 303(d).
The Integrated Report includes an assessment of each water body where data are available, and the list of waters identified under Section 303(d) as water quality limited and needing a TMDL.
Waters may be added to the 303(d) list based on evaluation of new data, application of new or revised water quality standards, or information showing water quality has declined.
Waters may be removed from the 303(d) list when TMDLs or other control measures have been established that are expected to improve water quality, when data show water quality has improved, and in some cases when water quality standards are revised.

Assessment information available for the 2010 Integrated Report includes:

Oregon's 2010 Integrated Report – Assessment Database and 303(d) List
A searchable database report with data for each water body, pollutant and location that have been assessed, and the conclusion about water quality in each water body.
Search options to display data including:
  • All waters in the state for all pollutants and conditions
  • Waters that are Water Quality Limited (Category 4 and Category 5)
  • Waters where pollutant Total Maximum Daily Loads need to be developed (Category 5 303(d) list)
  • Waters that have been de-listed and removed from Category 5 (303(d) list) in the 2010 assessment


EPA action on Oregon’s 2010 303(d) List 

DEQ’s comments on EPA’s proposed 303(d) additions, April 2012
EPA approval/disapproval action, March 2012

Other Information

Methodology for Oregon’s 2010 Water Quality Report and List of Water Quality Limited Waters    (May 2011)
The methodology contains the protocols and decision rules DEQ used to evaluate data and assign an assessment status category to each water body where data were reviewed.
Oregon's 2004/2006 Integrated Report consists of:
  • An assessment database with information on water quality for waters in Oregon (includes water quality limited waters and 303(d) list waters).
  • The assessment methodology used to evaluate data.
  • A schedule to develop TMDLs for waters identified in the Section 303(d) list.
  • A report titled Oregon's 2004 Water Quality Assessment Section 305(b) Report (submitted to EPA July 2004).

Assessment Process

DEQ began the biennial water quality assessment process by preparing a Draft Assessment Methodology and issuing a public call for submitting data and comments (April 1 to May 16, 2003).
DEQ evaluated water quality data for Oregon's waters using the "decision rules" in the Assessment Methodology for Oregon's 2004/2006 Integrated Report on Water Quality Status. DEQ assigned an assessment status category to each water body where data were available to evaluate. Water bodies that do not meet water quality standards are Water Quality Limited and are assigned Category 4 or Category 5. Water bodies in Category 5 need pollutant Total Maximum Daily Loads (TMDLs) developed and comprise the Section 303(d) list.
A public review and comment period on the draft list of water quality limited waters was open from September 9, 2005 to Nov. 7, 2005. The final list and Integrated Report reflect the public comments and changes made in response to comments. DEQ updated and revised Oregon's TMDL Priorities and Schedule based on the final 2004/2006 Section 303(d) list of Category 5 waters.

Water bodies assigned to Category 4 or Category 5 are Water Quality Limited. Water bodies assigned to Category 5 are water quality limited and need a TMDL developed (Section 303(d) list). DEQ has updated and revised Oregon's TMDL Priorities and Schedule based on Oregon's final 2004/2006 Section 303(d) list of Category 5 waters.

DEQ submitted Oregon's 2004/2006 Integrated Report and Section 303(d) list to EPA for review on May 23, 2006. EPA approves only the waters identified under Section 303(d) as needing TMDLs. DEQ made minor changes to the final 303(d) list during EPA's review.

2004/2006 Integrated Report

The 2002 Integrated Report and 303(d) List Database

Listed below are several options for searching or viewing Oregon's 2002 303(d) database.
  1. If you would like to search just the 303(d) listed waterbodies, then choose an option under 2002 303(d) List.
  2. If you would like to search the entire 303(d) database, including both listed and unlisted waterbodies, then choose an option under 2002 Integrated Report.
Note: The Integrated Report contains categories other than 303(d), including: "attaining", "potential concern", "TMDL approved", "insufficient/no data", and "water quality limited/not needing a TMDL."
You can search by selecting a watershed from a map of Oregon, you can search by selecting a waterbody from a list, or you can view the entire 303(d) list for the state.
Note: The following waterbodies must be searched by waterbody name: Snake River, John Day River, Klamath River, Deschutes River, Crooked River, Willamette River, Rogue River, Columbia River, Owyhee River, Grande Ronde River, Malheur River, Multnomah Channel.

2002 303(d) List

2002 Integrated Report

How to find a waterbody on the state map

  • Select the waterbody of interest from the scroll down menus in the 303(d) database.
  • Click on the record ID.
  • Note the LLID. The LLID is a unique identifier for each waterbody in the state. It uses the latitude and longitude at the mouth of the stream to identify the stream.
  • The LLID can be converted to latitude and longitude (in decimal degrees) by adding decimal points as follows:
​LLID ​Waterbody Name ​Latitude ​Longitude
​1201922443486 ​ Allen Creek ​ 44.3486 ​-120.1922
  • Type the latitude and longitude into the Latitude Longitude Identification Application.
  • You can then identify the stream by clicking on the highlighted point. You can use the identify tool to identify surrounding waterbodies. You can also add such features as cities and counties to the map.
  • Please note: Some waterbodies in the state are not yet assigned LLIDs. These waterbodies appear in the 303(d) database with artificial LLIDs such as "1111111111112". These waterbodies will not appear in the LLID Application map.


For more information on
the Integrated Report please contact:

Becky Anthony , 503-378-5319