Oregon Administrative Rules › Chapter 340 - DEPARTMENT OF ENVIRONMENTAL QUALITY › Division 41 - WATER QUALITY STANDARDS: BENEFICIAL USES, POLICIES, AND CRITERIA FOR OREGON › Section 340-041-0028 - Temperature

Current through Register Vol. 63, No. 7, July 1, 2024
(1) Background.
			 Water temperatures affect the biological cycles of aquatic species and are a
			 critical factor in maintaining and restoring healthy salmonid populations
			 throughout the State. Water temperatures are influenced by solar radiation,
			 stream shade, ambient air temperatures, channel morphology, groundwater
			 inflows, and stream velocity, volume, and flow. Surface water temperatures may
			 also be warmed by anthropogenic activities such as discharging heated water,
			 changing stream width or depth, reducing stream shading, and water
			 withdrawals.
(2) Policy. It is the
			 policy of the Commission to protect aquatic ecosystems from adverse warming and
			 cooling caused by anthropogenic activities. The Commission intends to minimize
			 the risk to cold-water aquatic ecosystems from anthropogenic warming, to
			 encourage the restoration and protection of critical aquatic habitat, and to
			 control extremes in temperature fluctuations due to anthropogenic activities.
			 The Commission recognizes that some of the State's waters will, in their
			 natural condition, not provide optimal thermal conditions at all places and at
			 all times that salmonid use occurs. Therefore, it is especially important to
			 minimize additional warming due to anthropogenic sources. In addition, the
			 Commission acknowledges that control technologies, best management practices
			 and other measures to reduce anthropogenic warming are evolving and that the
			 implementation to meet these criteria will be an iterative process. Finally,
			 the Commission notes that it will reconsider beneficial use designations in the
			 event that man-made obstructions or barriers to anadromous fish passage are
			 removed and may justify a change to the beneficial use for that water
			 body.
(3) Purpose. The purpose of
			 the temperature criteria in this rule is to protect designated
			 temperature-sensitive, beneficial uses, including specific salmonid life cycle
			 stages in waters of the State.
(4)
			 Biologically Based Numeric Criteria. Unless superseded by the natural
			 conditions criteria described in section (8) of this rule, or by subsequently
			 adopted site-specific criteria approved by EPA, the temperature criteria for
			 State waters supporting salmonid fishes are as follows:
(a) The seven-day-average maximum temperature
			 of a stream identified as having salmon and steelhead spawning use on subbasin
			 maps and tables set out in OAR 340-041-0101  to 340-041-0340: Tables 101B, and
			 121B, and Figures 130B, 151B, 160B, 170B, 220B, 230B, 271B, 286B, 300B, 310B,
			 320B, and 340B, may not exceed 13.0 degrees Celsius (55.4 degrees Fahrenheit)
			 at the times indicated on these maps and tables;
(b) The seven-day-average maximum temperature
			 of a stream identified as having core cold water habitat use on subbasin maps
			 set out in OAR 340-041-101 to 340-041-340: Figures 130A, 151A, 160A, 170A,
			 180A, 201A, 220A, 230A, 271A, 286A, 300A, 310A, 320A, and 340A, may not exceed
			 16.0 degrees Celsius (60.8 degrees Fahrenheit);
(c) The seven-day-average maximum temperature
			 of a stream identified as having salmon and trout rearing and migration use on
			 subbasin maps set out at OAR 340-041-0101  to 340-041-0340: Figures 130A, 151A,
			 160A, 170A, 220A, 230A, 271A, 286A, 300A, 310A, 320A, and 340A, may not exceed
			 18.0 degrees Celsius (64.4 degrees Fahrenheit);
(d) The seven-day-average maximum temperature
			 of a stream identified as having a migration corridor use on subbasin maps and
			 tables OAR 340-041-0101  to 340-041-0340: Tables 101B, and 121B, and Figures
			 151A, 170A, 300A, and 340A, may not exceed 20.0 degrees Celsius (68.0 degrees
			 Fahrenheit). In addition, these water bodies must have cold water refugia that
			 are sufficiently distributed so as to allow salmon and steelhead migration
			 without significant adverse effects from higher water temperatures elsewhere in
			 the water body. Finally, the seasonal thermal pattern in Columbia and Snake
			 Rivers must reflect the natural seasonal thermal pattern;
(e) The seven-day-average maximum temperature
			 of a stream identified as having Lahontan cutthroat trout or redband trout use
			 on subbasin maps and tables set out in OAR 340-041-0101  to 340-041-0340: Tables
			 121B, 140A, 190A, and 250A, and Figures 180A, 201A, 260A and 310A may not
			 exceed 20.0 degrees Celsius (68.0 degrees Fahrenheit);
(f) The seven-day-average maximum temperature
			 of a stream identified as having bull trout spawning and juvenile rearing use
			 on subbasin maps set out at OAR 340-041-0101  to 340-041-0340: Figures 130B,
			 151B, 160B, 170B, 180A, 201A, 260A, 310B, and 340B, may not exceed 12.0 degrees
			 Celsius (53.6 degrees Fahrenheit). From August 15 through May 15, in bull trout
			 spawning waters below Clear Creek and Mehlhorn reservoirs on Upper Clear Creek
			 (Pine Subbasin), below Laurance Lake on the Middle Fork Hood River, and below
			 Carmen reservoir on the Upper McKenzie River, there may be no more than a 0.3
			 degrees Celsius (0.5 Fahrenheit) increase between the water temperature
			 immediately upstream of the reservoir and the water temperature immediately
			 downstream of the spillway when the ambient seven-day-average maximum stream
			 temperature is 9.0 degrees Celsius (48 degrees Fahrenheit) or greater, and no
			 more than a 1.0 degree Celsius (1.8 degrees Fahrenheit) increase when the
			 seven-day-average stream temperature is less than 9 degrees Celsius.