The City of Salem operates under a Total Maximum Daily Load (TMDL) Plan regulated by Oregon Department of Environmental Quality (DEQ) to address warm summer stream temperatures. The water body receives a TMDL when a pollutant exceeds the amount for the beneficial uses of that water body. During the summer local water bodies exceed the temperature load. Increased sun exposure due to decreased tree canopy over the water body and warm water discharged into streams, creeks, and rivers lead to increased stream temperatures.

Warm Temperatures Affect Stream Life

The City of Salem works to increase streamside shade. Aquatic life, including resident and migratory fish and certain macroinvertebrates (small water bugs such as dragonfly and mayfly larvae) may be sensitive to warm water temperatures in our region. Warmer temperatures affect salmonid fish impacting their spawning, rearing, and migration.

Study Finds Low Tree Canopy on Salem Streams

Salem has approximately 90 miles of streams flowing through it, with most of the streamside area being privately owned. In 2009, Salem conducted its first streamside survey to determine the amount of tree canopy that shades Salem's streams. The study was recently updated using imagery from 2018. The study measured the tree canopy and shade within 30 feet of the stream in 10-foot segments. The study provided the following information:

1. High Shade: A 54% majority of stream reaches and land within 10-, 20-, and 30-foot buffers were over 75% shaded.
2. Mid-Level Shade: 28% of stream reaches and land within 10-, 20-, and 30-foot buffers had shade between 25-75%.
3. Low Shade: 18% of stream reaches and land within 10-, 20-, and 30-foot buffers had less than 25% shade

The next tree canopy and shade analysis will be conducted in 2029 and will include results from the 2021 ice storm.

Streamside property owners play a vital role in helping protect the health of streams flowing through Salem. Increasing shade is just one of the goals the City of Salem has for improving stream health. This page provides information on regulations to protect streams as well as resources for streamside property owners.

2019-2020 TMDL Annual Report