OAR 635-418-0015
Area Definitions and Dry Maintenance Time Periods for Watersheds in Agricultural Drainage Maintenance Regions as defined by Oregon Department of Agriculture administrative rule (OAR 603-095-4010)

(1) North Willamette Watershed
(a) That portion of the Lower Columbia River Basin, Sandy River Basin, and Lower Willamette River Basin described below.
(A) Lower Columbia River – Area definition: That portion of the Columbia River upstream of Hunt Creek to and including Herman Creek, including but not limited to the following river basins:
(B) Sandy River and all other tributaries, small basins, side channels, lakes, oxbows or sloughs that are associated with or drain directly into the Sandy River.
(C) Lower Willamette River – Area definition: That portion of the Willamette River basin downstream from the mouth of the Santiam River, including but not limited to the following river basins:
(b) Dry Maintenance Time Period: August 1 – August 31
(2) South Willamette River Watershed
(a) That portion of the Willamette River watershed upstream from and including the mouth of the Santiam River, including but not limited to the following river basins:
(b) Dry Maintenance Time Period: July 15 – September 15
(3) North Coast Watershed
(a) That portion of the state of Oregon west of the Oregon Coast Range crest and east of the Pacific Ocean extending from the mouth of the Columbia River south to and including Threemile Creek, including but not limited to the following river basins:
(b) Dry Maintenance Time Period: July 15 - August 31
(4) Coos-Coquille-Tenmile Lakes Watershed
(a) That portion of the state of Oregon west of the Oregon Coast Range crest and east of the Pacific Ocean extending from south of the South Jetty at Winchester Bay to the mouth of Twomile Creek, including but not limited to the following river basins:
(b) Dry Maintenance Time Period: July 15 - September 22
(5) South Coast Watershed
(a) That portion of the state of Oregon west of the Oregon Coast Range crest and east of the Pacific Ocean extending from the mouth of and including Twomile Creek south to the California state line. For the Rogue River, refer to the Rogue Watershed description. The South Coast watershed includes but is not limited to the following river basins:
(b) Dry Maintenance Period: July 15 - September 22
(6) Umpqua Watershed
(a) That portion of the state of Oregon west of the Cascade Mountains crest and east of the Pacific Ocean extending from south of Threemile Creek to and including the south jetty at Winchester Bay, including but not limited to the following river basins:
(A) Umpqua River and Bay and tributaries below Scottsburg Bridge, including Smith River - Area Definition: All tidally influenced areas within the Umpqua River and Bay and Smith River and the all other tributaries, small basins, side channels, lakes, oxbows, sloughs, or bays/estuaries that are associated with or drain directly into the Pacific Ocean and Umpqua River in the defined area and river basins described above.
(B) Umpqua River and tributaries above Scottsburg Bridge, including North Umpqua River and tributaries below Slide Creek Dam– Area Definition: All waters upstream of the Scottsburg Bridge including all waters upstream of the confluence of the North and South Umpqua Rivers excluding that portion above Slide Creek Dam, including but not limited to the following river basins:
(C) North Umpqua River and tributaries above Slide Creek Dam and all other tributaries, small basins, side channels, lakes, oxbows or sloughs that are associated with or drain directly into the North Umpqua River in the defined area and river basin described above.
(b) Dry Maintenance Time Periods:
(A) Umpqua River and Bay and tributaries below Scottsburg Bridge, including Smith River: July 15 - September 22
(B) Umpqua River and tributaries above Scottsburg Bridge, including North Umpqua River and tributaries below Slide Creek Dam : July 1 - September 30
(C) North Umpqua River and tributaries above Slide Creek Dam: July 15 - October 15
(7) Rogue Watershed
(a) That portion of the state of Oregon northeast of the Siskiyou Mountains and west of the Cascade Mountains crest including but not limited to the following river basins:
(A) Rogue River and tributaries below Dodge Bridge at Highway 234 (including but not limited to the Illinois and Applegate Rivers), and
(B) Rogue River and tributaries between Dodge Bridge and William Jess Dam at Lost Creek Lake, and all other tributaries, small basins, side channels, lakes, oxbows, or sloughs that are associated with or drain directly into the Rogue River in the defined area and river basin described above.
(C) Rogue River Basin and tributaries upstream of the William Jess Dam, and all other tributaries, small basins, side channels, lakes, oxbows, or sloughs that are associated with or drain directly into the Rogue River in the defined area and river basin described above.
(b) Dry Maintenance Time Periods:
(A) Rogue River and tributaries below Dodge Bridge at Highway 234: July 15 - September 30
(B) Rogue River and tributaries between Dodge Bridge and William Jess Dam at Lost Creek: July 15 – August 31
(C) Rogue River Basin and tributaries upstream of the William Jess Dam: July 15 – September 30
(8) Deschutes Watershed
(a) That part of the state of Oregon that includes but is not limited to the following river basins:
(b) Dry Maintenance Time Period: October 15 - November 15
(9) Klamath Watershed
(a) That part of the state of Oregon that includes but is not limited to the following river and lake basins:
(A) Klamath River Basin
(B) Closed Lakes Basin
(b) Dry Maintenance Time Periods:
(A) Klamath River Basin: September 1 - September 30
(B) Closed Lakes Basin: August 1 - September 30
(10) John Day Watershed
(a) That part of the state of Oregon upstream and including the mouth of the John Day River and east along the Columbia River to the Oregon-Washington Border, including but not limited to the following river basins:
(A) John Day River
(B) Umatilla River
(D) Mill Creek and tributaries and all other tributaries, small basins, side channels, lakes, oxbows, or sloughs that are associated with or drain directly into the defined area and river basins described above.
(E) Butter Creek and tributaries and all other tributaries, small basins, side channels, lakes, oxbows, or sloughs that are associated with or drain directly into the defined area and river basins described above.
(F) Willow Creek and tributaries and all other tributaries, small basins, side channels, lakes, oxbows, or sloughs that are associated with or drain directly into the defined area and river basins described above.
(b) Dry Maintenance Time Periods:
(A) John Day River and tributaries downstream of the confluence with the North Fork John Day River: July 15 – August 30
(B) John Day River and tributaries upstream of the confluence of the North Fork John Day River, including the North Fork John Day River: July 15 – August 15
(C) Umatilla River, Walla Walla River, Mill Creek, Butter Creek, and Willow Creek Basins: July 15 – September 30
(11) Grande Ronde Watershed
(a) That portion of the state of Oregon west of the Snake River where it forms the boundary between Oregon and Idaho from the Oregon/Washington border south to Birch Creek, and east of the summit of the Blue Mountains. This watershed has two distinct regions, the Grande Ronde - Imnaha basins, and the Powder - Burnt - Pine - Snake basins, and include but are not limited to the following river basins:
(A) Grande Ronde - Imnaha
(B) Powder - Burnt - Pine - Snake
(b) Dry Maintenance Time Periods:
(A) Minam River, Wallowa River, Wenaha River, Imnaha River upstream of Highway 350 Bridge, Grande Ronde upstream of Red Bridge State Park, Lookingglass Creek, and Catherine Creek upstream of Little Creek: July 1 – August 15
(B) Pine Creek upstream of the city of Carson, Pine Creek tributaries upstream of USFS boundary, and Powder River upstream of Phillips Reservoir and Elkhorn Tributaries: July 1 – August 31
(C) Grande Ronde River downstream of Wallowa River: July 1 – September 15
(D) Grand Ronde River between Wallowa River and Red Bridge State Park, Catherine Creek downstream of and including Little Creek, Imnaha River downstream of Highway 350 Bridge, Powder River downstream of Phillips Reservoir, Burnt River, Pine Creek downstream of the city of Carson, Pine Creek tributaries downstream of USFS boundary, and tributaries to the Snake River not mentioned: July 1 – October 15
(E) Snake River Reservoirs: July 1 – November 30
(F) Joseph Creek: July 1 – March 31
(12) Malheur Watershed
(a) That part of the state of Oregon that includes but not limited to the following river and lake basins:
(A) Snake River Basin
(B) Closed Lakes Basins
(b) Dry Maintenance Time Period:
(A) Closed Lakes Basins and Snake River tributaries excluding the sections described immediately below in (B): October 1 – November 15
(B) Malheur River and tributaries upstream of Wolf Creek, and North Fork Malheur River and tributaries upstream of Beulah Reservoir: August 1-August 31

Source: Rule 635-418-0015 — Area Definitions and Dry Maintenance Time Periods for Watersheds in Agricultural Drainage Maintenance Regions as defined by Oregon Department of Agriculture administrative rule (OAR 603-095-4010), https://secure.­sos.­state.­or.­us/oard/view.­action?ruleNumber=635-418-0015.

Last Updated

Jun. 8, 2021

Rule 635-418-0015’s source at or​.us