Section 040. Road Construction, Reconstruction And Maintenance

01. Purpose. Provide standards and guidelines for road construction, reconstruction, and maintenanc e that will maintain forest productivity, water quality, and fish and wildlife habitat. (3-31-22) 02. Road Specifications and Plans. Road specifications and plans must be consistent with good safet y practices. Landowners and Operators should plan each road to the minimum use standards adapted to the terrain an d soil materials to minimize disturbances and damage to forest productivity, water quality, fish, and wildlife habitat. I n addition, landowners and operators must: (3-31-22) a. Plan transportation networks to avoid road construction within SPZs, except at approaches to stream crossings. Leave or reestablish areas of vegetation between roads and streams. (3-31-22) b. Plan roads no wider than necessary to safely accommodate the anticipated use. Minimize cut an d fill volumes by aligning the road to fit the natural terrain features as closely as possible. Adequately compact fil l material. Dispose of excess material on geologically stable sites. (3-31-22) c. Plan roads to drain naturally by out-sloping or in-sloping with cross-drainage and by grade change s where possible. Install dips, water bars, cross-drainage, or subsurface drainage on roads when necessary. (3-31-22) d. When natural drainage will not protect the surface, cut slopes or fill slopes, plan roads with relief culverts and roadside ditches. Install culverts to prevent erosion of the fill by properly sizing, bedding an d compacting. Ensure drainage structures avoid direct discharge of sediment into streams. (3-31-22) e. This rule applies to new culvert installations, or reinstallations during road reconstructions o r because of catastrophic events. Temporary culvert crossings are exempt from the fifty (50) year peak flow desig n requirement but must be removed before seasonal run-off. (3-31-22) i. Culverts in fish-bearing streams must provide for fish passage. (3-31-22) ii

e of sediment into streams. (3-31-22) e. This rule applies to new culvert installations, or reinstallations during road reconstructions o r because of catastrophic events. Temporary culvert crossings are exempt from the fifty (50) year peak flow desig n requirement but must be removed before seasonal run-off. (3-31-22) i. Culverts in fish-bearing streams must provide for fish passage. (3-31-22) ii. Design stream crossings to carry the fifty (50) year peak flow using Department accepte d engineering methods or the culvert sizing table below. Armor the inlet or use a flared inlet structure on thirty (30 ) inch or greater diameter culverts. The minimum diameter culvert allowed is eighteen (18) inches. CULVERT SIZING TABLE The left side of this culvert sizing table will be used for the area of the state north of the Salmon River and within the South Fork Salmon River drainage; the right side will be used for the area of the state south of the Salmon River an d outside the South Fork Salmon River drainage. It was developed to carry the fifty (50) year peak flow at a headwater- to-diameter ratio of one (1). North Forest Region and South South Forest Region Fork Salmon River Drainage Watershed Area Required Culvert Diameter Culvert Capacity Watershed Area (acres) (inches) (in cubic feet/sec) (acres) Ditch relief, seeps, Ditch relief, seeps, 12 NA springs, wet areas, draws springs, wet areas, draws less than 32 18 6 Less than 72 33 - 74 24 12 73-150 75 - 141 30 20 151-270 142 - 240 36 32 271-460 241 - 366 42 46 461-720 367 - 546 48 65 471-1025 547 - 787 54 89 1026-1450 788 - 1027 60 112 1451-1870 1028 - 1354 66 142 1871-2415 1355 - 1736 72 176 2416-3355 1737 - 2731 84 260 3356-5335 North Forest Region and South South Forest Region Fork Salmon River Drainage Watershed Area Required Culvert Diameter Culvert Capacity Watershed Area (acres) (inches) (in cubic feet/sec) (acres) 2732 - 4111 96 370 5336-7410 4112 - 5830 108 500 7411-9565 5831 - 8256 120 675 9566-11780 Culverts larger than one hundred twenty (120) inches must be

5 - 1736 72 176 2416-3355 1737 - 2731 84 260 3356-5335 North Forest Region and South South Forest Region Fork Salmon River Drainage Watershed Area Required Culvert Diameter Culvert Capacity Watershed Area (acres) (inches) (in cubic feet/sec) (acres) 2732 - 4111 96 370 5336-7410 4112 - 5830 108 500 7411-9565 5831 - 8256 120 675 9566-11780 Culverts larger than one hundred twenty (120) inches must be designed; consider alternative structures. (3-31-22) iii. Relief culverts, and those used for seeps, springs, wet areas, and draws must not be less than twelv e (12) inches in diameter for permanent installations. (3-31-22) f. On existing roads that are not reconstructed or damaged by catastrophic events, landowners o r operators are encouraged, but not required, to replace or provide mitigation for culverts that do not provide for fis h passage in accordance with Subparagraph 040.02.e.i. or cannot carry the fifty (50) year peak flow of Subparagraph 040.02.e.ii. (3-31-22) g. Plan and install stream crossings in compliance with the Stream Channel Protection Act (Title 42 , Chapter 38, Idaho Code), Paragraph 030.07.b. and the culvert sizing requirements of Paragraph 040.02.e. Fords ar e acceptable stream crossing structures on small, shallow streams, with gradients less than four percent (4%). For fords: cross-drain and rock the road surface on each side of the stream for at least seventy-five (75) feet for Class I and a t least thirty (30) feet for Class II streams; minimize sediment delivery to streams by limiting use to low water, dry, o r frozen conditions; minimize hauling or equipment crossing trips during times of salmonid spawning and eg g incubation. (3-31-22) h. Avoid reconstruction of existing roads located in SPZs, except for approaches to stream crossings, unless it will result in the least long-term impact on site productivity, water quality, and fish and wildlife habitat . Reconstruction of existing roads in SPZs requires a variance

tions; minimize hauling or equipment crossing trips during times of salmonid spawning and eg g incubation. (3-31-22) h. Avoid reconstruction of existing roads located in SPZs, except for approaches to stream crossings, unless it will result in the least long-term impact on site productivity, water quality, and fish and wildlife habitat . Reconstruction of existing roads in SPZs requires a variance. Reusing existing roads in SPZs for skidding or landin g logs requires a variance. Reusing existing roads in SPZs only for hauling fully suspended logs does not require a variance. (3-31-22) 03. Road Construction. Landowners and operators must use the following practices to construct o r reconstruct roads in a way that prevents debris, overburden, and other material from entering streams. (3-31-22) a. Construct roads in compliance with the planning guidelines of Subsection 040.02. (3-31-22) b. Clear all debris generated during construction or maintenance which potentially interferes wit h drainage or water quality. Deposit excess material and slash on geologically stable sites outside the SPZs. (3-31-22) c. Where sediments would enter streams, stabilize exposed material (road surface, cut slopes, fill slopes, borrow pits, waste piles, etc.) prior to seasonal runoff. Install supplemental stabilization measures such as see d and mulch, slash mats, or rock. Rock the road surface through the entire SPZ over Class I stream crossings.(3-31-22) d. Compact road fills. Minimize snow, ice, or frozen soil buried in embankments. Significant wood y material is not allowed in fills, but slash may be used as a filter windrow along the fill toe in compliance with th e Idaho Forestry Act and Fire Hazard Reduction Programs, Title 38, Chapters 1 and 4, Idaho Code. (3-31-22) e. During and following operations on out-sloped roads, retain out-slope drainage and remove berm s on the outside edge, except those intentionally constructed for road grade fill protection. (3-31-22) f

fills, but slash may be used as a filter windrow along the fill toe in compliance with th e Idaho Forestry Act and Fire Hazard Reduction Programs, Title 38, Chapters 1 and 4, Idaho Code. (3-31-22) e. During and following operations on out-sloped roads, retain out-slope drainage and remove berm s on the outside edge, except those intentionally constructed for road grade fill protection. (3-31-22) f. Provide for drainage of quarries to prevent sediment from entering streams. (3-31-22) g. Construct cross-drains and relief culverts to minimize erosion. Use riprap, vegetative matter , downspouts, and similar devices to minimize erosion of the fill. Install drainage structures or cross-drain incomplet e roads prior to seasonal runoff. If effective forest floor filtration is not available within SPZs, install supplementa l filtration at drainage structure outlets or additional drainage structures outside SPZs to prevent road surface erosio n from entering streams. (3-31-22) h. Postpone earthwork or material hauling during wet periods if erodible material would ente r streams. (3-31-22) i. Remove or stabilize cut-slope material subject to sloughing concurrent with construction.(3-31-22) j. Construct full-bench roads, without fill slope disposal on slopes greater than sixty percent (60%) i n unstable or erodible soils. (3-31-22) 04. Road Maintenance. Landowners and operators must use the following practices for regula r preventive maintenance operations to minimize disturbance and damage to forest productivity, water quality, and fis h and wildlife habitat. (3-31-22) a. Place all debris or slide material associated with road maintenance in a manner to prevent their entry into streams. (3-31-22) b. Repair slumps, slides, and other erosion sources causing stream sedimentation to minimiz e sediment delivery. (3-31-22) c. Active forest roads are used for hauling forest products, rock and other road building materials. Conduct the following maintenance on active roads. (3-31-22) i. Keep culverts and ditches functional

road maintenance in a manner to prevent their entry into streams. (3-31-22) b. Repair slumps, slides, and other erosion sources causing stream sedimentation to minimiz e sediment delivery. (3-31-22) c. Active forest roads are used for hauling forest products, rock and other road building materials. Conduct the following maintenance on active roads. (3-31-22) i. Keep culverts and ditches functional. (3-31-22) ii. Crown, out-slope, in-slope, or cross-drain road surfaces during and upon completion of seasona l operations. Remove berms from the outside edge except those intentionally constructed for protection of fills. (3-31-22) iii. Maintain the road surface and postpone hauling during wet periods as necessary to minimize erosion of the subgrade and provide proper drainage. (3-31-22) iv. Apply road-surface stabilizing materials in a way that prevents their entry into streams. (3-31-22) v. During active maintenance, ensure road surfaces within SPZs are sufficiently stabilized. Instal l supplemental filtration at drainage structure outlets within SPZs if effective forest floor filtration is not available. (3-31-22) d. Incidental haul roads are roads with a primary purpose other than forest practices that are used fo r hauling logs during active harvest. Active road maintenance requirements apply. Once active road maintenance is completed, no other maintenance is required under the Act. (3-31-22) e. Inactive forest roads are no longer used for commercial hauling, but maintained for access . Conduct the following maintenance on inactive roads. (3-31-22) i. When active use is over, clear ditches and culverts, crown, out-slope, in-slope, cross-drain o r otherwise treat the road surface to minimize erosion. Maintain drainage structures as needed. (3-31-22) ii. The roads may be permanently or seasonally blocked to vehicle traffic. (3-31-22) f

ommercial hauling, but maintained for access . Conduct the following maintenance on inactive roads. (3-31-22) i. When active use is over, clear ditches and culverts, crown, out-slope, in-slope, cross-drain o r otherwise treat the road surface to minimize erosion. Maintain drainage structures as needed. (3-31-22) ii. The roads may be permanently or seasonally blocked to vehicle traffic. (3-31-22) f. Long-term inactive roads are forest roads that will not be used soon, but may be used again; n o subsequent maintenance is required following completion of the practices below: (3-31-22) i. Out-slope, cross-drain, seed or treat the surface to control erosion. (3-31-22) ii. Block the road to vehicle traffic. (3-31-22) iii. The Department may require the removal of bridges, culverts, ditches and unstable fills. Th e landowner must maintain any bridges or culverts left in place. (3-31-22) g. Permanently abandoned roads are forest roads not intended to be used again. Remove all drainag e structures and treat road surfaces to minimize erosion. (3-31-22) i. Restore stream gradients to their natural slope. (3-31-22) ii. Treat the road surface to break up compacted areas. (3-31-22) iii. Pull back fill slopes of roads within SPZs to a stable configuration unless long-term stability i s evident. (3-31-22) iv. Pull back unstable side-hill fills to a stable configuration. (3-31-22) v. Control ditch-line erosion by cross-draining, out-sloping, or regrading to eliminate ditches. (3-31-22) vi. Stabilize soil exposed from regrading, ripping, and drainage removal by seeding, mulching , armoring, or other treatment. (3-31-22) 05. Winter Operations. To minimize erosion and prevent damage to roads and constructed skid trail s from winter logging, operators must implement the practices below: (3-31-22) a. Install adequate road drainage prior to winter operations using rolling dips, drivable cross-drains , open-top culverts, out slopes, or other methods. (3-31-22) b. Maintain roads to keep the surface drained during thaws or break up

Operations. To minimize erosion and prevent damage to roads and constructed skid trail s from winter logging, operators must implement the practices below: (3-31-22) a. Install adequate road drainage prior to winter operations using rolling dips, drivable cross-drains , open-top culverts, out slopes, or other methods. (3-31-22) b. Maintain roads to keep the surface drained during thaws or break up. This may require activ e maintenance of existing drainage, drain holes in snow berms, and installation of additional cross-drains or treatmen t of the road surface. (3-31-22) 041. -- 049. (RESERVED)