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Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

1120 SW 5th Avenue, Room 1000, Portland, OR 97204

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Total Maximum Daily Loads (TMDLs)

The Oregon Department of Environmental Quality (DEQ) has established total maximum daily loads (TMDLs) for local rivers, which specify the maximum amount of pollutants that various entities can contribute to the Willamette River and tributaries that do not meet water quality standards. 

As one of those entities, the City of Portland has developed a TMDL Implementation Plan that identifies key management strategies to reduce TMDL pollutants from nonpoint (i.e., diffuse) sources and improve water quality.  Many of these strategies are similar to those used to reduce the discharge of pollutants from the City’s municipal separate storm sewer system (MS4) to receiving waters, since the strategies are applied citywide and are relevant to reducing pollution from both point (MS4) and nonpoint sources. The City submits an annual TMDL status report to DEQ to report on the implementation of the strategies.


2016 TMDL Annual Report (No. 8)

Portland's eighth annual status report for fiscal year 2015-16. This report provides information about activities the City accomplished during the year to protect watershed health and implement our TMDL strategies.

2015 TMDL Annual Report (No. 7)

Seventh annual TMDL status report for fiscal year 2014-15.

TMDL Implementation Plan

City of Portland Total Maximum Daily Load (TMDL) plan identifying key strategies that the City uses to reduce TMDL pollutants in order to restore and protect water quality in the Willamette River and local tributaries.