Recently, there has been a lot of press about Oregon and Washington governors using their authority under the Clean Water Act to require dam operators to reduce the heat they are introducing into the Snake and Columbia Rivers. Heat pollution causes substantial stress and even death for endangered salmon and steelhead. This is an important development in the ongoing effort to protect salmon and steelhead in these rivers… but what does it mean to reduce “heat pollution” and how does that protect salmon, steelhead and our ability to fish? Heat is explicitly identified as a pollutant under the Clean Water Act, making entities that heat waterways responsible for mitigating the temperature changes they cause. As anglers, we know that temperature changes have huge impacts on fish. Here in Oregon, our water quality standards have set a water temperature threshold of 68 degrees Fahrenheit for salmon and steelhead streams—the warmest water salmon and steelhead can survive in.