OAR 635-418-0110: 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: (i) Columbia River tributaries, (ii) Clatskanie River, and (iii) all other tributaries, small basins, side channels, lakes, oxbows or sloughs that are associated with or drain directly into the Columbia River in the defined area and river basins described above (excluding the Sandy and Willamette 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: (i) Multnomah Channel and tributaries (including but not limited to Scappoose and Milton Creeks), (ii) Columbia Slough, (iii) Johnson Creek, (iv) Clackamas River, (v) Abernathy Creek, (vi) Tualatin River, (vii) Beaver Creek, (viii) Molalla-Pudding Rivers, (ix) Chehalem Creek, (x) Yamhill River, (xi) Glenn Creek, (xii) Mill Creek, (xiii) Rickreall Creek, (xiv) Ash Creek, and (xv) all other tributaries, small basins, side channels, lakes, oxbows or sloughs that are associated with or drain directly into the Willamette River in the defined area and river basins described above. (b) Dry Maintenance Time Periods: (A) Lower Columbia River Basin, Sandy River Basin, and Lower Willamette River Basin excluding the river basins described immediately below in (B): August 1 – August 31 (B) Tualatin River, Yamhill River and Rickreall Creek: August 1 – September 30 (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: (A) Santiam River, (B) Luckiamute River, (C) Sidney Ditch and intersecting tributaries, (D) Truax Creek, (E) Burkhart Creek, (F) Cox Creek, (G) Periwinkle Creek, (H) Calapooia River, (I) Frazier Creek, (J) Stewart Slough, (K) Mary’s River, (L) Lake Creek, (M) Muddy Creek, (N) Flat Creek, (O) Long Tom River, (P) McKenzie River, (Q) Middle Fork Willamette River, (R) Coast Fork Willamette River, and (S) all other tributaries, small basins, side channels, lakes, oxbows, or sloughs that are associated with or drain directly into the Willamette River in the defined area and river basins described above. (b) Dry Maintenance Time Period: July 15 – September 30 (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: (A) Lower Columbia tributaries downstream of and including Hunt Creek, (B) Youngs Bay and tributaries (including but not limited to Lewis and Clark, Walluski, Youngs, Klaskanine Rivers), (C) Necanicum River, (D) Nehalem River, (E) Tillamook Bay and tributaries (including but not limited to Miami, Kilchis, Wilson, Trask, Tillamook Rivers), (F) Netarts Bay, (G) Sand Lake, (H) Nestucca River, (I) Neskowin River, (J) Salmon River, (K) Siletz River, (L) Yaquina River, (M) Alsea River, (N) Yachats River, (O) Siuslaw River, (P) Siltcoos River, and (Q) all other tributaries, small basins, side channels, lakes, oxbows, sloughs, or bays/estuaries that are associated with or drain directly into the Columbia River or Pacific Ocean in the defined area and river basins described above. (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: (A) Coos Bay and tributaries (including but not limited to Coos, South Coos, Millicoma Rivers), (B) Coquille River and tributaries, (C) Tenmile Lakes and tributaries, and (D) all other tributaries, small basins, side channels, lakes, oxbows, sloughs, or bays/estuaries that are associated with or drain directly into the Pacific Ocean in the defined area and river basins described above. (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: (A) New River, (B) Sixes River, (C) Elk River, (D) Euchre Creek, (E) Hunter Creek, (F) Pistol River, (G) Chetco River, (H) Winchuck River, and (I) all other tributaries, small basins, side channels, lakes, oxbows, sloughs, or bays/estuaries that are associated with or drain directly into the Pacific Ocean in the defined area and river basins described above. (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: (i) Elk Creek, (ii) Calapooya Creek, (iii) North Umpqua River and tributaries (including but not limited to Sutherlin Creek, Little River, and Rock Creek), (iv) South Umpqua River and tributaries (including but not limited to Lookingglass, Myrtle and Cow Creeks), and (v) all other tributaries, small basins, side channels, lakes, oxbows or sloughs that are associated with or drain directly into the North and South Umpqua Rivers in the defined area and river basins described above. (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 all other tributaries, small basins, side channels, lakes, oxbows, sloughs, or bays/estuaries that are associated with or drain directly into the Pacific Ocean or Rogue River in the defined area and river basin described above. (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: Columbia River tributaries upstream of Herman Creek to the mouth of the John Day River, Hood River, Deschutes River, and all other tributaries, small basins, side channels, lakes, oxbows, or sloughs that are associated with or drain directly into the Deschutes, Hood, or Columbia Rivers in the defined area and river basins described above. (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 (i) Klamath River, (ii) Williamson River, (iii) Sprague River, (iv) Sycan River and Marsh, (v) Lost River, (vi) Klamath Lake and tributaries, (vii) Agency Lake and tributaries, and (viii) 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) Closed Lakes Basin (i) Silver Lake and tributaries, (ii) Summer Lake and tributaries, (iii) Goose Lake and tributaries, (iv) Warner Lake and tributaries, (v) Chewaucan River, and (vi) 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 Period: August 1 – October 15 (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 (i) John Day River and tributaries downstream of the confluence with the North Fork John Day River at river mile 185 near the town of Kimberly, (ii) John Day River and tributaries upstream of the confluence with the North Fork John Day River at River mile 185 near the town of Kimberly, and (iii) all other tributaries, small basins, side channels, lakes, oxbows, or sloughs that are associated with or drain directly into the John Day River within the defined area and river basin described above. (B) Umatilla River (i) Umatilla River, both North and South Forks, (ii) Birch Creek, (iii) McKay Creek, (iv) Wildhorse Creek, (v) Meacham Creek, and (vi) 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. (C) Walla Walla River, upstream of the Washington and Oregon border (i) Walla Walla River, both North and South forks, (ii) Little Walla Walla River, (iii) Pine Creek, (iv) Cottonwood Creek, (v) Birch Creek, (vi) Couse Creek, and (vii) 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. (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 at river mile 185 near the town of Kimberly: July 15 – August 30 (B) John Day River and tributaries upstream of the confluence with the North Fork John Day River at River mile 185 near the town of Kimberly: 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 includes but is not limited to the following river basins: (A) Grande Ronde - Imnaha (i) Grande Ronde River, (ii) Catherine Creek, (iii) Lookingglass Creek, (iv) Minam River, (v) Wallowa River, (vi) Wenaha River, (vii) Joseph Creek, (viii) Imnaha River, (ix) 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) Powder - Burnt - Pine - Snake (i) Powder River, (ii) Burnt River, (iii) Pine Creek, (iv) Snake River from Washington state line to Annex, Oregon, (v) 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 Period: July 15 – August 15 (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 (i) Snake River upstream from Annex, Oregon to Idaho state line across the entire Snake River (located 7.25 miles upstream of the Oregon Route 452 bridge near Adrian, Oregon), (ii) Malheur River and tributaries upstream of Wolf Creek (including but not limited to Wolf Creek and Big Creek), (iii) Malheur River and tributaries between Wolf Creek and the Namorf Dam (including but not limited to Stinking Water Creek, and South Fork Malheur River), (iv) Malheur River from the Namorf Dam downstream to the confluence with the Snake River, (v) North Fork Malheur River and tributaries downstream of Beulah Reservoir to the confluence with the Malheur River, (vi) North Fork Malheur River and tributaries upstream of Beulah Reservoir, (vii) Willow Creek downstream of Malheur Reservoir, (viii) Bully Creek downstream of Bully Creek Reservoir, (ix) Owyhee River and tributaries, (x) Succor Creek within Oregon, (xi) Birch Creek (tributary to Snake River), and (xii) 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) Closed Lakes Basins (i) Malheur Lake Basin tributaries (including but not limited to Donner and Blitzen River, Silvies River, and Silver Creek), (ii) Coyote Lake Basin tributaries (includes Willow Creek and Whitehorse Creek), (iii) Catlow Valley tributaries (including but not limited to Home Creek, Threemile Creek, Rock Creek, and Skull Creek), (iv) Riddle Creek, (v) Alvord Lake Basin (including but not limited to Cottonwood Creek, Pike Creek, Trout Creek and Big Alvord Creek), (vi) Quinn River Basin (including but not limited to McDermitt Creek and its tributaries), and (vii) 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 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