NCC190682_ESC Approval Submitted (2)_20190620

of 27Apr. 23, 2019Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox Meadows14of 27Apr. 23, 2019Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox MeadowsPLAN DETAILS
of 27Apr. 23, 2019Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox Meadows15of 27Apr. 23, 2019Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox MeadowsPLAN DETAILS
of 27Apr. 23, 2019Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox Meadows16of 27Apr. 23, 2019Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox MeadowsPLAN DETAILS
of 27Apr. 23, 2019Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox Meadows17of 27Apr. 23, 2019Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox MeadowsTypical section & Profile Ridge Road
of 27Apr. 23, 2019Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox Meadows18of 27Apr. 23, 2019Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox MeadowsPurposeTo provide a buffer area where vehicles can drop their mud and sediment to avoid transporting it onto public roads, tocontrol erosion from surface runoff, and to help control dust.Conditions Where Practice AppliesWherever traffic will be leaving a construction site and moving directly onto a public road or other paved off-site area.Construction plans should limit traffic to properly constructed entrances.Design CriteriaAggregate Size—Use 2-3 inch washed stone.Dimensions of gravel pad—Thickness: 6 inches minimum,Width: 12-feet minimum or full width at all points of the vehicular entrance and exit area, whichever is greaterLength: 50-feet minimumLocation—Locate construction entrances and exits to limit sediment from leaving the site and to provide for maximum utilityby all construction vehiclesAvoid steep grades, and entrances at curves in public roads.Washing—If conditions at the site are such that most of the mud and sediment are not removed by vehicles traveling over thegravel, the tires should be washed. Washing should be done on an area stabilized with crushed stone that drains into asediment trap or other suitable disposal area. A wash rack may also be used to make washing more convenient and effective.Construction Specifications1. Clear the entrance and exit area of all vegetation, roots, and other objectionable material and properly grade it.2. Place the gravel to the specific grade and dimensions shown on the plans, and smooth it.3. Provide drainage to carry water to a sediment trap or other suitable outlet.4. Use geotextile fabrics because they improve stability of the foundation in locations subject to seepage or high water table.MaintenanceMaintain the gravel pad in a condition to prevent mud or sediment from leaving the construction site. This may requireperiodic topdressing with 2-inch stone. After each rainfall, inspect any structure used to trap sediment and clean it out asnecessary. Immediately remove all objectionable materials spilled, washed, or tracked onto public roadways.Temporary Check DamDefinitionPurposeConstruction SpecificationsMaintenanceCondition where practice appliesTemporary Check DamStone check dam stone should be placed over the channel banks to keep water from cutting around the dam.This condition may not be met at 12% ditch line grade. Space at 50' to 75' intervalsConstruction Entrance DetailTemporary Check Dam DetailPlan symbol
of 27Apr. 23, 2019Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox Meadows19of 27Apr. 23, 2019Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox MeadowsSediment Fence DetailsDefinitionPurposeCondition where practice appliesInstallation SpecificationsMaintenanceInstallation detail of a sediment fence"J" hook ends of sediment fence uphill to provide storage capicitySilt fencePlan Symbol
of 27Apr. 23, 2019Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox Meadowsof 27Apr. 23, 2019Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox MeadowsTemporary Sediment Trap Details and Computations20Temporary Sediment TrapDefinition: A small temporary ponding basin formed by an embankment or excavation to capture sediment.Purpose: To detain sediment-laden runoff and trap the sediment to protect receiving streams, lakes, drainagesystems, and protect adjacent property.Conditions Where Practice Applies: Specific criteria for installation of a temporary sediment trap are asfollows:·At the outlets of diversions, channels, slope drains, or other runoff conveyances that dischargesediment-laden water.·Below areas that are draining 5 acres or less.·Where access can be maintained for sediment removal and disposal.·In the approach to a stormwater inlet below a disturbed area as a part on an inlet protection system.·Structure life limited to 2 years.Temporary Sediment Trap Construction Specifications1. Clear, grub, and strip the area under the embankment of all vegetation and root mat. Remove all surface soilcontaining high amounts of organic matter, and stockpile or dispose of it properly. Haul all objectionable materialto the designated disposal area.2. Ensure that fill material for the embankment is free of roots, woody vegetation, organic matter, and otherobjectionable material. Place the fill in lifts not to exceed 9 inches, and machine compact it. Over fill theembankment 6 inches to allow for settlement.3. Construct the outlet section in the embankment. Protect the connection between the riprap and the soil frompiping by using filter fabric or a keyway cutoff trench between the riprap structure and soil.·Place the filter fabric between the riprap and the soil. Extend the fabric across the spillway foundation andsides to the top of the dam; or·Excavate a keyway trench along the center line of the spillway foundation extending up the sides to theheight of the dam. The trench should be at least 2 feet deep and 2 feet wide with 1:1 side slopes.4. Clear the pond area below the elevation of the crest of the spillway to facilitate sediment cleanout.5. All cut and fill slopes should be 2:1 or flatter.6. Ensure that the stone (drainage) section of the embankment has a minimum bottom width of 3 feet andmaximum side slopes of 1:1 that extend to the bottom of the spillway section.7. Construct the minimum finished stone spillway bottom width, as shown on the plans, with 2:1 side slopesextending to the top of the over filled embankment. Keep the thickness of the sides of the spillway outletstructure at a minimum of 21 inches. The weir must be level and constructed to grade to assure design capacity.8. Material used in the stone section should be a well-graded mixture of stone with a d50 size of 9 inches (class Berosion control stone is recommended) and a maximum stone size of 14 inches. The stone may be machineplaced and the smaller stones worked into the voids of the larger stones. The stone should be hard, angular, andhighly weather-resistant.9. Discharge inlet water into the basin in a manner to prevent erosion. Use temporary slope drains or diversionswith outlet protection to divert sediment-laden water to the upper end of the pool area to improve basin trapefficiency (References: Runoff Control Measures and Outlet Protection).10. Ensure that the stone spillway outlet section extends downstream past the toe of the embankment until stableconditions are reached and outlet velocity is acceptable for the receiving stream. Keep the edges of the stoneoutlet section flush with the surrounding ground, and shape the center to confine the outflow stream (References:Outlet Protection).11. Direct emergency bypass to natural, stable areas. Locate bypass outlets so that flow will not damage the12.Stabilize the embankment and all disturbed areas above the sediment pool and downstream from thetrap immediately after construction (References: Surface Stabilization).13.Show the distance from the top of the spillway to the sediment cleanout level (1/2 the design depth) onthe plans and mark it in the field.14. Install porous baffles as specified in Practice 6.65, Porous Baffles. embankment.MaintenanceInspect temporary sediment traps at least weekly and after each significant (½ inch or greater) rainfall event andrepair immediately. Remove sediment, and restore the trap to its original dimensions when the sediment hasaccumulated to one-half the design depth of the trap. Place the sediment that is removed in the designateddisposal area, and replace the part of the gravel facing that is impaired by sediment.Check the structure for damage from erosion or piping. Periodically check the depth of the spillway to ensure itis a minimum of 1.5 feet below the low point of the embankment. Immediately fill any settlement of theembankment to slightly above design grade. Any riprap displaced from the spillway must be replacedimmediately.After all sediment-producing areas have been permanently stabilized, remove the structure and all unstablesediment. Smooth the area to blend with the adjoining areas, and stabilize properly (References: SurfaceStabilization).Plan and cross-section of a temporary sediment trapDisturbed areas 1-5 calculated August 2018 forinstallation of temporary sediment traps pertinent toclearing and grubbing. Drainage has been changed to dispersion ( pipes andchannels) by interim construction. Best management practices may indicate abandoningtemporary sediment traps and going directly toinstallation of dissapators.54321Temporary Sediment TrapPlan symbol (drawn to scale on detail plans)
of 27Apr. 23, 2019Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox Meadows21of 27Apr. 23, 2019Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox MeadowsChannel Size & Stablization8.1.3.4.6.7.5.2.·123546789101112131415Road swale ditch channelPlan symbol
Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox Meadows22Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox MeadowsStorm Drainage Designof 27Apr. 23, 2019
Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox Meadows23Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox MeadowsInet Stabilization Structure Detailof 27Apr. 23, 2019Plan symbol At all new pipe inlets,except stream crossing pipes 5 , 11 andmaybe 4 (sse note on plan detail (1) Sheet 10)
Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox Meadows24Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox MeadowsOutlet Stabilization Structure Detail & ComputationsStorm Drainage DesignA grade transition has been added to accommodate previous Forest Servicegrade specification. An alternate to this structure could be a plunge pool.Definition:A structure designed to control erosion at the outlet of a channel or conduit.Purpose :To prevent erosion at the outlet of a channel or conduit by reducing the velocity of flow and dissipating energy.Conditions Where Practice Applies:This practice applies where the discharge velocity of a pipe, box culvert, diversion, open channel, or other water conveyance structure exceedsthe permissible velocity of the receiving channel or disposal area.Planning Considerations:The outlets of channels, conduits, and other structures are points of high erosion potential because they frequently carry flows at velocities thatexceed the allowable limit for the area downstream. To prevent scour and undermining, an outlet stabilization structure is needed to absorb theimpact of the flow and reduce the velocity to non-erosive levels. A riprap-lined apron is the most commonly used practice for this purposebecause of its relatively low cost and ease of installation. The riprap apron should be extended downstream until stable conditions are reachedeven though this may exceed the length calculated for design velocity control.Design Criteria Capacity—10-year, peak runoff or the design discharge of the water conveyance structure, whichever is greater.Grade—Ensure that the apron has zero grade. There should be no overfall at the end of the apron; that is, the elevation of the top of the riprapat the downstream end should be the same as the elevation of the bottom of the receiving channel or the adjacent ground if there is no channel.Alignment—The apron should be straight throughout its entire length, but if a curve is necessary to align the apron with the receivingstream, locate the curve in the upstream section of riprap.Materials—Ensure that riprap consists of a well-graded mixture of stone.Larger stone should predominate, with sufficient smaller sizes to fill the voids between the stones. The diameter of the largest stone size shouldbe no greater than 1.5 times the d50 size.damage.Thickness—Make the minimum thickness of riprap 1.5 times the maximum stone diameter.Stone quality—Select stone for riprap from field stone or quarry stone. The stone should be hard, angular, and highly weather-resistant. Thespecific gravity of the individual stones should be at least 2.5.Filter—Install a filter to prevent soil movement through the openings in the riprap. The filter should consist of a graded gravel layer or asynthetic filter cloth. Design filter blankets by the method described in Practice 6.15, Riprap.Construction Specifications:1. Ensure that the subgrade for the filter and riprap follows the required lines and grades shown in the plan. Compact any fill required in thesubgrade to the density of the surrounding undisturbed material. Low areas in the subgrade on undisturbed soil may also be filled by increasingthe riprap thickness.2. The riprap and gravel filter must conform to the specified grading limits shown on the plans.3. Filter cloth, when used, must meet design requirements and be properly protected from punching or tearing during installation. Repair anydamage by removing the riprap and placing another piece of filter cloth over the damaged area. All connecting joints should overlap so the toplayer is above thedownstream layer a minimum of 1 foot. If the damage is extensive, replace the entire filter cloth.4. Riprap may be placed by equipment, but take care to avoid damaging the filter.5. The minimum thickness of the riprap should be 1.5 times the maximum stone diameter.6. Riprap may be field stone or rough quarry stone. It should be hard, angular, highly weather-resistant and well graded.7. Construct the apron on zero grade with no overfill at the end. Make the top of the riprap at the downstream end level with the receiving areaor slightly below it.8. Ensure that the apron is properly aligned with the receiving stream and preferably straight throughout its length. If a curve is needed to fitsite conditions, place it in the upper section of the apron.9. Immediately after construction, stabilize all disturbed areas with vegetationMaintenance:Inspect riprap outlet structures weekly and after significant (1/2 inch or greater) rainfall events to see if any erosion around or below the ripraphas taken place, or if stones have been dislodged. Immediately make all needed repairs to prevent further damage.of 27Apr. 23, 2019
of 27Apr. 23, 2019Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox Meadows25of 27Apr. 23, 2019Red FoxMeadowsErosion and Sedimentation Control Planfor Construction of Subdivision Roads atRed Fox MeadowsVegetative PlanGround Stabilization CriteriaConstruction ScheduleMaintenance PlanConstruction ScheduleObtain Plan approval and permits:·Obtain approval of erosion control plan.·Obtain any grading permits required by Caldwell County.·Obtain plan approval by Forest Service.·NC DOT did not require a driveway permit for this project (driveway to single family residence).Hold pre-construction meeting:·Meet with owner, grading contractor, governmental representatives, and plan developer.·Project is divided into seven phases per optimum placement of temporary sediment traps at 500-750 foot intervals. Each phase isto be completed before sequencing to the next.·Each phase is further divided into segments defined by the crossing of the new road construction with the old roadbed.Install temporary silt fence and temporary sediment trap:·Utilize existing entrance and old road for initial measures.·Undergrowth and brush are to be removed in vicinity of temporary silt fence to first temporary sediment trap.·Install silt fence as specified.·Clear area for temporary sediment trap and install as specified, if needed, grade a temporary diversion ditch across existing oldroad to send road drainage into temporary sediment trap.Clearing and grubbing:·Segment work into sections defined by the intersection of the new road with the old road.·Start at the highest segment and work down.·Determine placement of debris bury pit in an old roadbed segment as not to interfere with project access. Typically, start atlowest point in an old roadbed segment.·Dig pit to accommodate current day's debris.·Remove brush, trees, and stumps in new segment to old road crossing.·Limb cleared material for compaction.·Bury and compact debris in pit.·Cover at the end of the day and grade to original natural grade.·Fertilize, lime, and seed as specified.·Start enough of next day's pit to create berm and sediment pit to protect finished grading and seeding.·Clearing and grubbing of the remaining segments of the new road are to be done in segments exposing limited areas ofconstruction as project progresses.Construction entrance:·Construct construction entrance as specified after clearing and grubbing of initial segment.Grading:·Grade a segment of new road to plan grade.·Install other specified drainage measures: culverts, lead off ditches, and dissipators per specifications.·Install pits and rock filter check dams in ditch lines.Gravel, ditch line, shoulder, cut slope, and fill slope stabilization:·As each segment progresses, prepare cut, fill, and shoulder areas for seeding as specified.·Gravel completed segment of roadbed.·Fertilize, lime and seed exposed areas as specified.·Install ditch liners as specified.Maintain temporary measures.·Maintain sediment and erosion control measures per maintenance plan.·Maintain rainfall data log as required.·Reseed as necessary.Remove temporary measures:·Once vegetation is established and temporary measures are no longer required, they should be removed, as specified, for ease ofpermanent maintenance.·If required, grade to final contours and fertilize, lime and seed as specified.Repeat processes:·Repeat sequence, starting at clearing and grubbing, (except for construction entrance) for each segmental crossing of oldroadbed.·Once each phase of project is completed down to temporary sediment trap, start over at sequence of installing silt fence and nexttemporary sediment trap.Maintenance PlanErosion control devices:·Follow all maintenance procedures outlined with structure details.·All measures will be inspected after each runoff producing rainfall. Any needed repairs will be made before any grading isdone.·Sediment will be removed from the ditch line traps and temporary sediment traps and placed in the in the fill slope.·The silt fences should be checked regularly and after any rainfall. Sediment that builds up along the fence or large rocks rollinto the fence are to be removed and the fence repaired. the gravel filters in the fence line are to be cleaned regularly.·All areas seeded will be fertilized and reseeded as necessary according to the vegetative plan to maintain a dense vegetativecover.·Maintenance of measures specified must be followed and repairs made immediately.Vegetative PlanSeed bed preparation:·On fill slopes leave the leave the last 4 to 6 inches loose and un-compacted. Roughen slope by tracking with bulldozer.·On cut slopes, roughen as construction is in process.Temporary seeding·Cut and fill slopes will be temporarily seeded with German millet at a rate of 40 lb/acre in summer months (May 15th to August15th) and with Rye at a rate of 120 lb/acre and Annual lespedeza at a rate of 50lb/acre if done in the late winter or early spring.·Lime is to be applied at a rate of 2000 lb/acre·10-10-10 fertilizer is to be applied at a rate of 750 lb/acre.Permanent seeding for 2.52 acres (4.05 acres less 1.53 acres of 18' road width)·All areas, exclusive of gravel roadbed, are to be seeded with the following mixture:Lime4000 lb/acreFertilizer1000 lb/acreKentucky bluegrass 80 lb/acre (use blend of three varieties)Redtop 10 lb/acreSericea Lespedeza 20 lb/acreKobe lespedeza 10 lb/acreMulch,hydro-seeded:4000 lb/acre (preferred method)·Mulch, hand-seeded:4000 lb/acre Straw, as required for adequate coverage. Use matting or staking on cut slopes as necessary.·Alternative 1: Immediately hand seed with permanent mixture and straw mulching all areas brought to finish grade. Thenhydro-seed all areas needing reseeded in phases.·Alternative 2: Immediately hand seed with permanent mixture and straw mulch all areas except cut banks. Hand seed cut banksper temporary specifications. Then hydro-seed cut banks and all other areas needing reseeded in phases.Seeding frequency·For compliance with General Stormwater DWQ Permit groundcover will be provided according to the following schedule·Also see requirements on following Sheet 26.
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26 Red Fox Meadows Erosion and Sedimentation Control Plan
for Construction of Subdivision Roads
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Apr. 23, 2019
27 Red Fox Meadows Erosion and Sedimentation Control Plan
for Construction of Subdivision Roads