These needs are the same regardless of where the fish live. Scientific evidence has shown that these species have existed in all 19 basins of the state, and that they begin to show negative physiological effects beginning at about 58 degrees Fahrenheit. Based on this requirement there is no reason for setting separate standards based on geography or climate. To get stream temperature information, continuous recording temperature sensors are placed at well mixed water locations in streams during the seasons when maximum temperatures are expected. The monitoring locations must be representative of the waterbody, have presence or passage of salmon, trout or other fish species, and be accessible.
Quality assurance requires calibration and periodic auditing of sensors.
People overseeing the monitors download from the sensors to a portable computer, then format and send to an electronic database used to determine instream compliance with the temperature standards. Determining whether the stream temperature is above or below the temperature standard is based on the average of the maximum daily water temperatures for the stream s warmest, consecutive seven-day period during the year. A one time measurement above the standard will NOT be considered a violation of the standard. If stream temperatures are above the standard during a time when the air temperatures are exceptionally hot, it is not considered a violation. Exceptionally hot air temperatures are measured against the average maximum temperature that would be expected to occur over a seven-day period once every ten years.