Erosion And Sediment Control Guidelines
Erosion and sedimentcontrol for forestryoperationsGUIDELINESMarch 2013Bay of Plenty Regional Council5 Quay StreetPO Box 364Whakatāne 3158NEW ZEALAND
Bay of Plenty Regional CouncilGuideline 2012/04 (Reformatted March 2013)ISSN: 1179-9595 (Print)ISSN: 1179-9609 (Online)Bay of Plenty Regional Council5 Quay StreetPO Box 364Whakatāne 3158NEW ZEALANDPrepared by Norm Ngapo, Bridget Robson, John Douglas, Steve Pickles and Dwayne McKay
ContentsIntroduction5Why we need guidelines5How these guidelines work5How these guidelines relate to forest industry guidelines5Erosion and sediment control in the Bay of Plenty6Do I need a resource consent?7When do I need to control erosion and sediment?7Controlling erosion and sedimentation8Different forms of erosion8Guidelines for forestry operations11Planning11Operations12Forestry earthworks13Land preparation17Planting and tending18Planning19Maintenance after the operation21Best Management Practices23Water table controls25BMP 1.1 Check dams26BMP 1.2 Rock lining29Runoff controls30BMP 2.1 Runoff diversion channel/bund31BMP 2.2 Contour drain33BMP 2.3 Water bars/cut-offs35BMP 2.4 Bale barrier37BMP 2.5 Flume/pipe drop structure38BMP 2.6 Outlet controls/energy dissipaters40Erosion and sediment control guidelines for forestry operations3
4Surface stabilisation41BMP 3.1 Mulching/bark/logging residue42BMP 3.2 Surface vegetation – hydroseeding43BMP 3.3 Surface vegetation – grassing44Sediment control46BMP 4.1 Soak hole/sediment trap47BMP 4.2 Sediment retention fencing – silt fence48BMP 4.3 Soak hole plus silt fence50BMP 4.4 Sediment retention fencing – super silt fence51BMP 4.5 Sediment retention pond – silt pond54Other measures56BMP 5.1 Permeable slash bunds57BMP 5.2 Corduroying58BMP 5.3 Geosynthetic erosion control systems t requirements64Other consents or permits64Harvest Plan example65Erosion and sediment control guidelines for forestry operations
IntroductionWhy we need guidelinesHow these guidelines workThese guidelines provide advice for land usersundertaking plantation forestry operations. Theyoutline the principles of erosion and sedimentcontrol, give guidelines to minimise erosion andsedimentation for plantation forestry and providespecifications and standards for erosion andsediment control practices. They replace the July2000 Erosion and Sediment Control Guidelinesfor Forestry Operations.Section 1 – covers erosion and sedimentation,and the principles for controlling them. Hereyou’ll find information on general principles toconsider when you’re planning or carrying outforestry operations.We need guidelines because:1. All land preparation and forestestablishment should be planned andcarried out in a way that matches how youintend to harvest.2. All plantation forestry operations shouldbe carried out using management practicesthat protect soil and water.Section 2 – covers guidelines for planningand implementing forestry operations, It includesa guide for preparing consent applications, andguidance for forestry operations where consentsaren’t needed.Section 3 – includes specifications forparticular erosion and sediment control practicesand design requirements for these. These canbe used in consent applications, and cited asminimum design standards in consent conditions.In the appendices you’ll find an example of aHarvest Plan that could be used for a resourceconsent application, and a guide to help you workout if your proposed activity needs consent.How these guidelines relate to forest industry guidelinesForest industrytechnicalNZ Forest RoadEngineeringManualNEW ZEALAND FORESTROAD ENgiNEERiNg MANuALForest industry operatorguidelinesCouncil guidelinesBOPRC Forestry GuidelinesExpands on sections 4.10 and 6.3of NZ Forest Road EngineeringManual.Forestry EarthworksConstruction Guide forOperatorsNZ FOREST ROAD ENGINEERING MANUALOPERATORS GUIDEN Z FO R E ST OW N E R S AS S O C I AT I O N I N CNZ FOREST OWNERS ASSOCiATiON iNCLevel 993 The TerraceWellingtonLevel 9www.nzfoa.org.nz93 The TerraceWellingtonwww.nzfoa.org.nzFor engineers.For planners, supervisors andcompliance staff.For operators.Erosion and sediment control guidelines for forestry operations5
Erosion and sedimentcontrol in the Bay of PlentyLand in the Bay of Plenty is used for many things.Many uses – earthworks, roading, and clearingvegetation – can cause erosion and sedimentationproblems. The erosion and sediment controlmeasures in this guide apply to a range of differentplantation forestry work.Our Bay of Plenty soils are very susceptible tosurface erosion and erosion caused by flowingwater (fluvial erosion), particularly from poorlycontrolled stormwater runoff. We need gooderosion and sediment control.Our water resources are valued for their highquality, and wide range of potential uses.Sediment does occur naturally, but large amountscan damage our natural environment. Sedimentladen runoff from poorly managed land activitiescan affect: stream values – modified or destroyedestuarine or coastal habitatsfauna and flora – buried, choked or abradedfood sources (changes) and life cyclespumps and water supplies.Effects can be long-term – stream life can takeyears rather than months to recover – or it can setoff other effects. A pulse of sediment in a streamsystem can start an erosion cycle which can bedifficult to control. Suspended sediment canalso be a carrier for other contaminants, such asphosphorus.If you follow the principles and practices outlinedin this Guideline you can reduce the adverseeffects of land disturbance.Most of the soils in the Bay of Plenty are formedfrom volcanic eruptions. Some are young and havehad limited time to develop, and these ash andpumice soils are extremely prone to surface andfluvial erosion.Soil texture is dominated by sand and silt,rather than clay. This means they are easilyworked. Using simple runoff controls and surfacestabilisation techniques can prevent on-siteerosion problems. Unless deeper clay layers areexcavated, or earthworks continue into winter,you may not need more stringent treatmenttechniques. Erosion and sediment controltechniques for sand and silt are generally muchsimpler than those required for clay.Poorly planned earthworks and/or harvest operations can result in erosion and potentialdownstream effects.6Erosion and sediment control guidelines for forestry operations
In the Bay of Plenty we have very deep depositsof volcanic ash and volcanic flow. There areunconsolidated pumice and ash, more cementedsilts, ashes and sands and buried soils. Somedeeper and more consolidated layers may besaturated. When these layers are excavated, theyform springs. In some areas, there are also oldlake beds with very fine-grained deposits proneto liquefaction. Any land disturbance involvingdeeper cuts and fills may disturb materials that dohave a higher clay and/or water content. You willneed more stringent erosion and sediment controlsystems to reduce adverse off-site effects.Do I need a resourceconsent?The Bay of Plenty Regional Water and Land Plan1(RWLP) has several rules on land managementactivities that require a resource consent. TheRMA2 requires resource consents for activities todo with river beds, using natural water and anydischarges.When do I need to controlerosion and sediment?For any land disturbance activity or vegetationremoval, you have to consider what erosion andsediment control is needed.If you need a consent, erosion and sedimentcontrols will be an integral part of the consentconditions. In most cases the consent should bein place before earthworks start. In some forestrysituations where there is adequate vegetation orsurface protection, erosion and sediment controlscan be installed as works progress – particularly infirst rotation plantation forests.Control measures are also required when sites areclosed down. Controls need to be maintained untilthe area is fully stabilised.If consent is not required, the guidelines andpractices in section 3 provide guidance aboutwhat needs to be considered to ensure thatany proposed works don’t create adverseenvironmental effects.If you don’t know whether you need a resourceconsent, contact Bay of Plenty Regional Council on0800 884 880.12December 2008Resource Management Act 1991.Typical Bay of Plenty soils; deep ash and pumice layers.Erosion and sediment control guidelines for forestry operations7
Controlling erosion andsedimentationErosion is a natural process – earth is slowlyloosened and removed (usually by wind andrain). Erosion can be sped up by what we do onthe land. Erosion rates are affected by the type ofsoil, surface cover, topography (steepness) andclimate. Human activities on soil, surface coverand changing the slope of the land can all increaseerosion. There are two kinds:Control of stormwater runoff is especiallyimportant, as this is usually on bare ground whereit is easier for water to erode and pick up soilparticles.Pumice is a problem in the Bay of Plenty. It islight and can travel a long way downstream beforesettling. It can also cause blockages in smallerdiameter culverts.1. surface erosion (splash and sheet),2. fluvial erosion (from water flow). This leadsto rill and gully erosion on-site and streamand channel erosion off-site.Different forms of erosionSedimentation occurs when earth particlestransported by wind and water settle somewhere.How quickly depends mostly on the particle sizeand speed of runoff. Heavy particles, like graveland sand, settle out sooner than the finer particleslike silt and clay. Clay particles can stay suspendedin water for long periods, causing discolouration.To control erosion and sedimentation you needto control water speed so it doesn’t ever gain theenergy to pick up and carry soil.8Erosion and sediment control guidelines for forestry operationsBecause finer particles can be difficult to captureonce they are on the move, the best way to controlsediment is to prevent erosion.Control involves:1. Protecting the soil surface from rainfalland stormwater runoff (erosioncontrol).2. Capturing eroded particles on-site(sediment control).
1. Keep disturbed areas small andexposure time short Plan construction activities to minimise thearea and time that bare soils are exposed. Take the season into account and avoidwinter earthworks. For short-term,sensitive operations, check the weatherforecast. Plan operations to stage constructionworks. Limit the construction area of eachstage. Stabilise disturbed areas quickly.Regardless of the season, look atrevegetation as each stage is completed.You can repeat this in autumn or spring.2. Control erosion at source Don’t rely on controlling sediment later. Prevent erosion and sediment removal bykeeping on-site water speed low. Control stormwater runoff so that it doesn’tmove fast enough to scour. Disperse waterat stable discharge points. Use diversiondrains and bunds on gentle grades. And usethe water backed up behind check damsor in soak holes - so it can act as a plungepool).3. Install perimeter controls Isolate the disturbed area to contain andcontrol on-site problems. Keep the works site divided into separatecatchment areas so that clean runoff waterfrom undisturbed areas is kept separatefrom sediment-laden runoff draining thedisturbed areas. Clearly mark the boundary of the workingarea using fences, flags, signs, high visibilitytape etc to stop machinery going intoundisturbed areas.4. Try to keep sediment on site Make every effort to minimise sedimentdischarge. Before starting, figure out where sedimentcontrol measures should go. Installcontrols before any large scale operationscommence. Where possible, incorporate somestormwater detention capacity into thesediment control devices. Large-scale earthworks will need sedimentcontrol systems to be designed to ensurethat they can cope with critical storm flows.5. Protect critical areas Fit the development to existing siteconditions. Consider how to protect steep slopes andwatercourses. Retain as much existing vegetation aspossible to help erosion and sedimentcontrol, particularly to filter runoff.NOTE: Clearing native vegetation may requirea specific consent.6. Inspect and maintain controlmeasures Set up a maintenance schedule for regularinspections, and inspect the works duringwet weather to check that stormwaterrunoff controls are working properly. Be flexible, and continually assess youroperations. Long-term monitoring of controls will showwhere you can improve design and fine tuneconstruction practices, for instance smallchanges to design and construction maysignificantly reduce erosion or sedimentproduction.Erosion and sediment control guidelines for forestry operations9
To ensure you have a feedback loop,either have someone on-site responsiblefor construction and monitoring erosionand sediment controls, or have very goodcommunication and hand-over betweenpeople responsible.Erosion control involves both stabilising thesurface and controlling runoff. Stabilise the surface using vegetation,mulch, aggregate – anything that protects thesoil surface from erosion. Use suitably experienced people to installand monitor erosion and sediment controlmeasures. Maintain sediment controls to ensure theyretain their storage capacity.Runoff control includes slowing downthe speed of stormwater runoff, as well asdissipating the runoff at numerous dischargepoints. Keep water speed low by havinggradients as flat as possible. This will alsoreduce turbulence, which can start erosion. Minimise earthworks.Control erosion at source. Trap water that is carrying sediment insediment traps, soak holes or vegetation whereit can be managed. Once the speed of the water is slowed,sediment falls out and settles. Emptysediment traps regularly, so they always havestorage volume free.Endeavour to keep sediment on site.Road side gullying.10Sediment control means keeping sediment onsite.Erosion and sediment control guidelines for forestry operations
Guidelines for forestryoperationsPlanningForward planning is essential for all forestryoperations. Poor planning can be costly long-term.Appendix 2 has an example of a Harvest Plan,setting out earthworks and logging methods.You need harvest planning experience to do this.Ideally, the contractor who will do the operationshould also be involved in this planning phase.If not, the planner needs to be aware of all of theconstraints that the contractor will encounter.Tailoring planting boundaries to match theproposed harvesting method is very important,to minimise impacts on soil and water. Thisdoesn’t mean detailed harvest planning before aforest is established, but it does mean you need toconsider:You need a physical plan showing: Future access options for harvesting, Types of harvesting systems likely to be used, Environmental constraints that you need totake into account at harvesting. boundaries/areas covered by the operation, topographical features and/or contours, water bodies, proposed earthworks (roads, tracks, landings),stream crossings, proposed stream side management measures,It’s extremely important to choose the correctharvest system. If it is not appropriate for the siteconditions, adverse effects are more likely, nomatter how well an operation is carried out. proposed haul direction (harvestingoperations),Poor planning can result in excessive earthworksand poorly-sited skids. proposed erosion and sediment controlmeasures, environmental features (pā sites, protectedreserves etc.), other features that need to be considered(public roads, electricity pylons etc.). the scale of the plan needs to be have enoughdetail to identify features easily when you areon site. Ensure planting boundaries are matchedto an appropriate harvesting method. Choose a logging system appropriateto site conditions – you need harvestplanning experience to do this. If you choose the wrong logging systemfor harvesting, best logging practiceswon’t help.Erosion and sediment control guidelines for forestry operations11
OperationsMany forestry activities require skilled operators.A well-planned operation still needs to beimplemented well so that soil and water values arenot adversely affected.You need attention to detail at construction andwhen carrying maintenance for sound erosion andsediment control. Successful erosion and sedimentcontrol relies on regular monitoring andmaintenance. Always check erosion and sedimentcontrols before and after heavy rain. When operations are completed, ensurethe control systems are sized to cope withthe likely level of follow-up maintenance.The contractor is the key, as they construct erosionand sediment control measures. Successful erosion and sediment controlrelies on attention to detail. Minimise earthworks. Control erosion at source. Endeavour to keep sediment on site.Monitoring and maintenanceYou must monitor and maintain erosion andsediment control measures.During the operational phase, all erosion andsediment control structures must be checked on aregular schedule, as well as before and after heavyrainstorm events.When operations are completed erosion andsediment controls. Leave them in a condition thatprovides for follow-up maintenance. For example,if you won’t be using a track for a number of years,install deep water bars or soak holes that don’tneed much maintenance, and spread slash/loggingmulch over the track.Set up an inspection programme once operationsare complete, based on the use level and risksposed by the erosion control works. For exampleyou’ll need regular monitoring and maintenanceof erosion and sediment control structures nearsensitive features.12Erosion and sediment control guidelines for forestry operationsStreamside managementMany operations can damage streams and otherwater bodies. You can reduce this by forwardplanning and careful work practices, but the risksincrease the closer the operation is to the water.If you’re working beside a stream the mainproblem is sediment discharge. The best way todeal with this is to use a specific managementsystem.Earthworks have the highest risk of dischargingsediment into streams, so controlling operationsand stormwater is the key to avoiding problems.The simplest and most successful method isto keep all earthmoving machinery well clearof streams by marking a “no-go” area at anappropriate distance from the stream.Use natural benches and terraces to help set no-goareas close to streams. Avoid earthworks on slopesthat fall directly into streams. Earthworks operations near streams havea high risk of creating sediment problems. Keep well clear of watercourses whenundertaking earthworks, except at streamcrossings.
Forestry earthworksMany earthworks operations are done to formpermanent assets. Planning and attention toconstruction detail will influence their workinglife.conjunction with salvage logging, construct themonto benches and leave at least an extra metreof bench visible to place stumps and other heavywoody debris.Earthworks can be a major source of sediment,and have the greatest impact on soil and watervalues. All earthworks should be carefully plannedfor location, construction, runoff control andmaintenance.Plan runoff control so that the discharge willbe controlled and directed to a safe outlet, suchas a stable ridge, or through vegetation. Neverdischarge runoff directly onto fill slopes. Anydischarge over a fill slope must be safely flumedor piped to a stable low point where the dischargecan be dissipated.You should move as little soil as possible tocomplete the job. Disturbed ground should bestabilised as soon as possible when you’ve finishedthe works. Earthworks should be kept well clear ofwater bodies, and out of lowest points of dry gullyfloors.Always key earthworks into natural ground,compact fill slopes in layers, and avoid buryingorganic or woody material into structural fill. Always key your earthworks intonatural ground. Compact fill material in layers. Do not bury organic or woody material instructural fill.Roadin
outline the principles of erosion and sediment control, give guidelines to minimise erosion and sedimentation for plantation forestry and provide specifications and standards for erosion and sediment control practices. They replace the July 2000 Erosion and Sediment Control Guidelines for Forestry Operations. We need guidelines because: 1.
WATERSHED MANAGEMENT ORDINANCE TECHNICAL GUIDANCE MANUAL 5/26/2020 4.1 GENERAL SOIL EROSION AND SEDIMENT CONTROL REQUIREMENTS PAGE 4-2 4.1 GENERAL SOIL EROSION AND SEDIMENT ONTROL REQUIREMENTS §400.1 of the WMO requires erosion and sediment control practices for all projects, rega
A number of east coast jurisdictions have sediment and erosion control manuals which address factors influencing erosion and sedimentation. The following is reproduced from the “1983 Maryland Standards and Specifications for Soil Erosion and Sediment Control”, (Reference 1).
Mar 07, 2020 · Chapter 7 - Erosion and Sediment Control Section 7D-1 - Design Criteria 2 Revised: 2013 Edition B. Erosion Control The key to successful erosion and sediment control on construction sites is the prevention of erosion. The simplest way to keep sediment from
Erosion and Sediment Control Design Guide 4‐1 4.0 EROSION AND SEDIMENTATION PROCESS Erosion Erosion is a geological process in which earthen materials are worn away by naturally occurring agents
NDDOT Erosion & Sediment Control - Construction Course Wind Erosion and Deposition 29 Erosion Facts (USDA NRCS Soil Quality - Urban Technical Note No. 1 "Erosion and Sedimentation on Construction Sites") Construction sites can erode at a rate of 100 to 500 tons/acre/year 100 times greater than cropland 2,000 times greater than woodlands 30
EROSION & SEDIMENT CONTROL GUIDELINES FOR URBAN CONSTRUCTION . remove from water once they have been suspended as sediment. However, the effects of the fine grained soil particles can be detrimental to aquatic habitat. . where soils less than 40 microns are found. Based on monitoring of recently designed sediment ponds, clay sized particles .
Erosion is the detachment and movement of soil particles by wind, water, and gravity. Natural erosion (geologic erosion) is a process that occurs slowly over millions of years. Geologic erosion has shaped the landscape around us. Accelerated erosion is NOT
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