OAR 660-023-0090: Riparian Corridors

(1) For the purposes of this rule, the following definitions apply: (a) “Fish habitat” means those areas upon which fish depend in order to meet their requirements for spawning, rearing, food supply, and migration. (b) “Riparian area” is the area adjacent to a river, lake, or stream, consisting of the area of transition from an aquatic ecosystem to a terrestrial ecosystem. (c) “Riparian corridor” is a Goal 5 resource that includes the water areas, fish habitat, adjacent riparian areas, and wetlands within the riparian area boundary. (d) “Riparian corridor boundary” is an imaginary line that is a certain distance upland from the top bank, for example, as specified in section (5) of this rule. (e) “Stream” is a channel such as a river or creek that carries flowing surface water, including perennial streams and intermittent streams with defined channels, and excluding man-made irrigation and drainage channels. (f) “Structure” is a building or other major improvement that is built, constructed, or installed, not including minor improvements, such as fences, utility poles, flagpoles, or irrigation system components, that are not customarily regulated through zoning ordinances. (g) “Top of bank” shall have the same meaning as “bankfull stage” defined in OAR 141-085-0010(12). (h) “Water area” is the area between the banks of a lake, pond, river, perennial or fish-bearing intermittent stream, excluding man-made farm ponds. (2) Local governments shall amend acknowledged plans in order to inventory riparian corridors and provide programs to achieve Goal 5 prior to or at the first periodic review following the effective date of this rule, except as provided in OAR 660-023-0250(5). (3) Local governments shall inventory and determine significant riparian corridors by following either the safe harbor methodology described in section (5) of this rule or the standard inventory process described in OAR 660-023-0030 as modified by the requirements in section (4) of this rule. The local government may divide the riparian corridor into a series of stream sections (or reaches) and regard these as individual resource sites. (4) When following the standard inventory process in OAR 660-023-0030, local governments shall collect information regarding all water areas, fish habitat, riparian areas, and wetlands within riparian corridors. Local governments may postpone determination of the precise location of the riparian area on lands designated for farm or forest use until receipt of applications for local permits for uses that would conflict with these resources. Local governments are encouraged, but not required, to conduct field investigations to verify the location, quality, and quantity of resources within the riparian corridor. At a minimum, local governments shall consult the following sources, where available, in order to inventory riparian corridors along rivers, lakes, and streams within the jurisdiction: (a) Oregon Department of Forestry stream classification maps; (b) United States Geological Service (USGS) 7.5-minute quadrangle maps; (c) National Wetlands Inventory maps; (d) Oregon Department of Fish and Wildlife (ODFW) maps indicating fish habitat; (e) Federal Emergency Management Agency (FEMA) flood maps; and (f) Aerial photographs. (5) As a safe harbor in order to address the requirements under OAR 660-023-0030, a local government may determine the boundaries of significant riparian corridors within its jurisdiction using a standard setback distance from all fish-bearing lakes and streams shown on the documents listed in subsections (a) through (f) of section (4) of this rule, as follows: (a) Along all streams with average annual stream flow greater than 1,000 cubic feet per second (cfs) the riparian corridor boundary shall be 75 feet upland from the top of each bank. (b) Along all lakes, and fish-bearing streams with average annual stream flow less than 1,000 cfs, the riparian corridor boundary shall be 50 feet from the top of bank. (c) Where the riparian corridor includes all or portions of a significant wetland as set out in OAR 660-023-0100, the standard distance to the riparian corridor boundary shall be measured from, and include, the upland edge of the wetland. (d) In areas where the top of each bank is not clearly defined, or where the predominant terrain consists of steep cliffs, local governments shall apply OAR 660-023-0030 rather than apply the safe harbor provisions of this section. (6) Local governments shall develop a program to achieve Goal 5 using either the safe harbor described in section (8) of this rule or the standard Goal 5 ESEE process in OAR 660-023-0040 and 660-023-0050 as modified by section (7) of this rule. (7) When following the standard ESEE process in OAR 660-023-0040 and 660-023-0050, a local government shall comply with Goal 5 if it identifies at least the following activities as conflicting uses in riparian corridors: (a) The permanent alteration of the riparian corridor by placement of structures or impervious surfaces, except for: (A) Water-dependent or water-related uses; and (B) Replacement of existing structures with structures in the same location that do not disturb additional riparian surface area. (b) Removal of vegetation in the riparian area, except: (A) As necessary for restoration activities, such as replacement of vegetation with native riparian species; (B) As necessary for the development of water-related or water-dependent uses; and (C) On lands designated for agricultural or forest use outside UGBs. (8) As a safe harbor in lieu of following the ESEE process requirements of OAR 660-023-0040 and 660-023-0050, a local government may adopt an ordinance to protect a significant riparian corridor as follows: (a) The ordinance shall prevent permanent alteration of the riparian area by grading or by the placement of structures or impervious surfaces, except for the following uses, provided they are designed and constructed to minimize intrusion into the riparian area: (A) Streets, roads, and paths; (B) Drainage facilities, utilities, and irrigation pumps; (C) Water-related and water-dependent uses; and (D) Replacement of existing structures with structures in the same location that do not disturb additional riparian surface area. (b) The ordinance shall contain provisions to control the removal of riparian vegetation, except that the ordinance shall allow: (A) Removal of non-native vegetation and replacement with native plant species; and (B) Removal of vegetation necessary for the development of water-related or water-dependent uses. (c) Notwithstanding subsection (b) of this section, the ordinance need not regulate the removal of vegetation in areas zoned for farm or forest uses pursuant to statewide Goals 3 or 4; (d) The ordinance shall include a procedure to consider hardship variances, claims of map error, and reduction or removal of the restrictions under subsections (a) and (b) of this section for any existing lot or parcel demonstrated to have been rendered not buildable by application of the ordinance; and (e) The ordinance may authorize the permanent alteration of the riparian area by placement of structures or impervious surfaces within the riparian corridor boundary established under subsection (5)(a) of this rule upon a demonstration that equal or better protection for identified resources will be ensured through restoration of riparian areas, enhanced buffer treatment, or similar measures. In no case shall such alterations occupy more than 50 percent of the width of the riparian area measured from the upland edge of the corridor.