Iowa DNR has prepared a draft 2020 list of impaired waters as required by Section 303(d) of the federal Clean Water Act. This list is also known as "Category 5" of Iowa's 2020 Integrated Report. Iowa DNR is now seeking public comments on this draft list. Public comments will be solicited from December 1, 2020, through January 1, 2021. Following the end of the public comment period, the draft list will be modified based on the comments received, and the revised list will be forwarded to U.S. EPA for their review and approval or disapproval. Please mail comments to:
Comments can also be e-mailed to Iowa DNR at the following address:IRcomment@dnr.iowa.gov.
Iowa's draft 2020 list of Section 303(d) impaired waters (Category 5 of the Integrated Report). The list contains 586 waterbodies with a total of 775 impairments. There were 622 waterbodies with 831 impairments on Iowa's 2018 final EPA-approved list.Iowa's draft 2020 Methodology and links to additional materials for review can be found on the Publications page.
Iowa's Section 303(d) lists and Integrated Reports are prepared according to Iowa DNR's assessment and listing methodology and follow U.S. EPA guidelines for "integrated reporting" that combine requirements of Sections 305(b), 303(d), and 314 of the federal Clean Water Act. These U.S. EPA guidelines suggest that states place all their waters into one of the following categories that comprise a state's Integrated Report:
[*Designated uses are beneficial uses applied to specific Iowa surface waters (streams, rivers, lakes, and wetlands) in the Iowa Water Quality Standards. Examples of beneficial uses are uses for primary contact recreation (for example, swimming-type uses), aquatic life protection, and as a source of water for a public water supply. Beneficial uses designated for Iowa's surface waters are protected by narrative and numeric water quality criteria. For a more detailed description of designated uses applied to Iowa surface waters, see pages 9 and 10 [Surface Water Quality Criteria, Designated Use Segments] of the Iowa Water Quality Standards. For a list of the Iowa surface waters and their respective designated uses, see Iowa's Surface Water Classification.]
Waterbodies that Fully meet WQ standards are those that are in Integrated Report Categories 1 and 2. Potentially impaired waters are placed on Iowa's list of Waters in Need of Further Investigation (WINOFI), and Impaired waterbodies include all those in Integrated Report Categories 4 and 5.
The number of assessments the Iowa DNR can make in a given cycle are limited by budgets and staffing resources. The following charts show the proportions to which each waterbody type meets WQ standards, and the percentage that has been assessed in this cycle.
|Category - Description||Waterbody Segments|
|1 - All designated uses are met.||16|
|2 - Some of the designated uses are met but there is insufficient data to determine if remaining designated uses are met.||268|
|3 - Insufficient data exist to determine whether any designated uses are met.||1546|
|4 - Water is impaired or threatened and a TMDL has been completed or is not needed.||166|
|5 - Water is impaired or threatened and a TMDL is needed.||584|