Tualatin River Farm- Part Two: Part of a Cooling System

There’s a problem-

“The Tualatin River and most of its tributaries have been designated water quality limited under Section 303(d) of the Clean Water Act, and in 2001 the Oregon Department of Environmental Quality issued… requirements for (improving water quality).” Clean Water Services: Revised Temperature Management Plan, page 1.

As part of the requirements, Total Maximum Daily Loads (a measured amount of a specific pollution discharge permitted to enter a river on a daily basis and still meet water quality standards) were specified for temperature. The TMDL dictates an allowable amount that human activities can warm a stream above natural conditions. The Tualatin River watershed was, for the most part, in excess of allowable temperature perameters.

Here’s why-

Run-off (from farm fields,  urban landscapes, and logging activities) and waste water treatment effluent, coupled with excess solar radiation reaching water due to inadequate vegetated buffers, collectively cause the Tualatin to be warmer…