These water crossing standards have been developed collaboratively with input from the Ministry of Natural Resources and Forestry (MNRF), Department of Fisheries and Oceans (DFO) and representatives from Ontario’s forest industry. They represent minimum levels of performance requirements that must be met by proponents when constructing and removing water crossings using the proponent self-screening approval framework detailed in this Protocol.

The conditions and requirements included in the general and specific water crossing standards have been deemed by MNRF and DFO staff as the necessary mitigation measures required to classify the water crossing project as not likely to result in the death of fish or harmful alteration, disruption or destruction (HADD) to fish habitat. If a proponent determines that the requisite water crossing standards that apply to their specific project can be implemented, they may proceed with their activity, so long as the water crossing standards notification requirements are met, and forest management approval processes outlined in this Protocol and the appropriate version of Forest Management Planning Manual (FMPM) are followed.

In cases where a proponent determines that the requisite water crossing standards that apply to their specific project cannot be implemented, a review and approval will be required by either MNRF and/or DFO as per the approval framework outlined in this Protocol.

Failure to follow the requirements of these water crossing standards could result in compliance and enforcement actions under both the Fisheries Act and the Crown Forest Sustainability Act (CFSA).

Part 3.0 of this section details water crossing construction and removal best management practices and mitigation measures. Although not mandatory, it is highly recommended that proponents consider these best management practices and mitigation measures in relation to the planning, design, construction, maintenance and removal of water crossing. The tools and approaches contained in this section support proponents in meeting the water crossing standards included in part 1.0 and 2.0 in this section.

Part 1.0 – general water crossing standards that apply to all water crossings

This general water crossing standard applies to all water crossings during construction or removal under the authority of the CFSA for which a self-screening approval approach is being implemented. Additional measures that are specific to certain water crossing types or structures must also be implemented and are detailed in part 2.0 of this section.

General standards

  • The implementation of water crossing standards (i.e. type and location of project) must be consistent with the applicable and approved Forest Management Plan (FMP).
  • The implementation of water crossing standards must be overseen or carried out by individuals who are trained and competent to:
    • understand the intent and objectives of the specification’s standards;
    • ensure that specification’s water crossing standards and appropriate mitigation measures are satisfactorily applied; and
    • recognize when water crossing standards and appropriate mitigation measures have not been satisfactorily implemented and understand the requirements to report and correct any mistakes that have occurred.
  • The project must be compliant with applicable water crossing standards and guidelines in the most recent versions of Ontario’s forest management guide(s) that address the conservation of biodiversity at the landscape scale and the stand and site scales and MNRF's Crown land bridge manual.

Design and location

  • The project does not include watercourse realignment.
    • Projects are designed and constructed in a way that minimizes loss or disturbance to riparian vegetation. The removal of riparian vegetation must be restricted to the disturbance footprint required for the construction and/or removal of water crossings.

Erosion and sediment control

  • Erosion and sediment control measures must be installed prior to the commencement of construction or removal activities to prevent the release of sediment or other deleterious substances to the watercourse. Erosion and sediment control measures will be:
    • Effective and installed properly with respect to the site conditions;
    • Inspected regularly during construction with any necessary repairs being made if any damage occurs;
      • Maintained until the site has become stabilized through the permanent re-establishment of vegetation (i.e., a root mass has been established that ensures site stabilization), either naturally or through planting and tending activities within disturbed areas and approaches, and/or they have been stabilized with rip-rap, or appropriately sized non-erodible aggregate material.
  • Fill material placed below the normal high water mark will be erosion-resistant and/or protected from erosion.
  • Water crossings are to be constructed and removed to help ensure that storm water runoff from bridge decks, side slopes, and road approaches and ditches are directed away from the watercourse and into a retention pond or vegetated areas to remove suspended solids, dissipate velocity, and prevent sediment and other deleterious substances from entering the watercourse. Erosion and siltation in ditch lines adjacent to watercourse crossing approaches are to be controlled by using sediment traps such as rock/soil dams or log jams as site conditions warrant.
  • Crossing sites are to be stabilized during and post construction and removal, including any material stockpiling, spoil, and/or other waste materials to prevent sediment or other deleterious substances from entering the watercourse. Cut and fill slopes around the water crossing structure and removed sites are to be stabilized at a 2:1 slope or stable angle of repose for the materials used using site appropriate methods.

Fish and fish habitat

  • At any time of year, the free movement of water and the passage of fish may not be blocked or otherwise impeded up and down stream of the crossing, with the exception of a temporary blockage due to water crossing construction/removal activities.
  • All in-water construction and removal activities must abide by the appropriate fisheries in-water timing windows documented in approved FMPs and/or forest management guides in order to avoid disrupting sensitive fish life stages. In cases where the fishery community inventories at the location of the proposed project are not well documented, the most restrictive in-water timing window must be used.
  • All in-water construction and removal activities must be undertaken in an uninterrupted fashion and be completed in an appropriate timeframe to minimize the potential for site disturbance.
  • The construction and removal activities must not employ the use of any explosives.

Construction and maintenance

  • Machinery must be maintained free of fluid and fuel leaks.
  • Machinery must be operated on land with tracks/wheels above the normal high water mark, or on ice in a manner that avoids disturbance to the banks of the watercourse and adjacent riparian vegetation areas.
  • Machinery must be washed, refueled and serviced a minimum of 30 metres away from the watercourse. Fuel and other materials for the machinery are to be stored a minimum of 30 metres away from the watercourse to minimize the chance of any deleterious substance from entering the water.
  • Removal of riparian vegetation must be restricted to the disturbance footprint required for the construction and removal of water crossings. Site-specific operational and/or safety concerns that warrant the removal of additional riparian vegetation will be determined on a case-by-case basis and will be kept to a minimum within the road right-of-way in order to help maintain the stability of watercourse banks.
  • All debris resulting from construction and removal activities must be removed from the work site following the completion of the undertaking.
  • If machinery fording the watercourse is required during the course of construction activities, it will be limited to a one-time event (over and back) per piece of equipment that is essential to implementation of the project, and must occur only if an existing crossing at another location is not available or practical to use.
    • If minor rutting is likely to occur, watercourse bank and bed protection methods (e.g. swamp mats, pads) are to be used provided they do not constrict flows or block fish passage;
    • Grading of the watercourse banks for the approaches is not permitted;
    • If the watercourse bed and banks are steep and highly erodible (e.g. dominated by organic materials and silts) and erosion and degradation are likely to occur as a result of equipment fording, a temporary crossing structure or other practice must be used to protect these areas;
    • The one-time fording must adhere to the appropriate in-water timing windows; fording must occur under low-flow conditions and not when flows are elevated due to local rain events or seasonal flooding.
  • Aquatic invasive species are introduced and spread through transporting sands and sediments and using contaminated construction equipment. To prevent aquatic invasive species during construction in aquatic environments:
    • clean, drain and dry any equipment used in the water
    • never move organisms or water from one body of water to another

Part 2.0 – water crossing standards that apply to specific water crossings structures/practices

The following water crossing standards apply to specific water crossing structures and/or practices and must be implemented in addition to the general water crossing standards outlined in part 1.0 of this section.

2.1 – water crossing standards for the construction of clearspan bridges

This water crossing standard applies to the construction of clear span bridges and their footprints, including associated abutments, cribs and/or sill logs.

General standards

  • The conditions and requirements of the general water crossing standards must be implemented in addition to, and in conjunction with, this water crossing standard.

Design and location

  • Bridges must not be located on meander bends, braided watercourses, alluvial fans, or any other area that is inherently unstable and may result in the alteration of natural stream functions or erosion and scouring of the water crossing structure.

Erosion and sediment control

  • Appropriate site-specific mitigation measures must be enacted to ensure the construction of clearspan bridges, including bridge cribs, abutments, and associated fill slopes are not subjected to the impacts of long-term or ongoing erosion. At a minimum, measures must include:
    • Clearspan bridges, including bridge cribs and fill slopes must be stabilized with appropriately sized non-erodible material (e.g. rocks, cobble sized stones). Rock used to stabilize crossings and watercourse banks will be clean, free of fine materials, and of sufficient size to resist displacement during peak flood events. The rock must be placed at the original watercourse bank grade to ensure there is no infilling or narrowing of the watercourse.
    • Fill material placed below the normal high water mark of the watercourse must be erosion resistant and/or protected from erosion.

Fish and fish habitat

  • The project must not be located within 100 metres of fish spawning or sensitive habitat if any in-water work is a requirement of the project.

Construction and maintenance

  • The bridge, including its abutments, must be placed entirely outside the normal high water mark.
  • The construction of clearspan bridges must not result in the alteration of the bed or banks of the watercourse or infilling or narrowing of the watercourse channel.

2.2 – water crossing standards for the removal of clearspan bridges

This water crossing standard applies to the removal of clear span bridges and their footprints, including associated abutments, cribs and/or sill logs. In certain cases, local site conditions may create a higher likelihood for potential damage to watercourse banks and/or fish habitat when bridges abutments, cribs, and/or sill logs are completely removed as opposed to leaving them in place. In these cases, proponents must ensure that appropriate sedimentation and erosion mitigation measures, in addition to any necessary public safety actions, continue to be implemented.

General standards

  • The conditions and requirements in the general water crossing standards must be implemented in addition to, and in conjunction with, this water crossing standard.
  • Removal of water crossings will only occur if it is consistent with the approved road use management strategy in the applicable FMP and is scheduled for removal in the current annual work schedules (AWS) (table AWS-2).

Erosion and sediment control

  • Upon removal, including the removal of bridge abutments, cribs, and/or sill logs, the site must be stabilized and protected against erosion.
  • Bridge abutments and cribs may be left in place if they are in good condition, stable for the long term, are not affecting watercourse or fish community dynamics, and are permissible in the approved FMP and/or AWS-2 table.
  • Surface water runoff and road approaches and ditches must be directed away from the watercourse and into vegetated areas. Diagonal berms or waterbars must be installed where the erosion potential of the road approaches is likely to result in the road’s gravel surface and underlying fill being deposited into the watercourse over time. Sediment traps used within ditch lines adjacent to the watercourse crossing approach should be replaced and/or maintained to their original condition at the time of crossing removal.

Fish and fish habitat

  • The project must not be located within 100 metres of fish spawning or sensitive habitat if any in-water work is a requirement of the project.

Construction and maintenance

  • The removal of clearspan bridges, including the removal of bridge abutments, cribs and/or sill logs will not result in the alteration of the bed or banks of the watercourse or infilling or narrowing of the watercourse channel.

2.3 – water crossing standards for the construction of open bottom arch culverts

Arch culverts are open-bottom structures that typically span the width of the waterbody channel, require minimal in-water construction activities and result in minimal impacts to the banks of the waterbody.

General standards

  • The conditions and requirements in the general water crossing standards must be implemented in addition to, and in conjunction with, this water crossing standard.

Design and location

  • The arch culvert must not be located on meander bends, braided watercourses, alluvial fans, or any other area that is inherently unstable and may result in the alteration of natural steam functions or erosion and scouring of the water crossing structure.
  • Culverts must be sized to a minimum Q25 design flow using MNRF water engineering/calculation software, or equivalent software programs deemed acceptable by the MNRF.

Erosion and sediment control

  • Appropriate site-specific mitigation measures must be enacted to ensure the construction of arch culverts and associated footings and fill slopes are not subjected to the impacts of long-term or ongoing erosion. At a minimum, measures must include:
    • Stabilizing the crossing, including footings and fill slopes, with appropriately sized non-erodible material (e.g. rocks, cobble sized stones). Rock used to stabilize crossings and watercourse banks must be clean, free of fine materials, and of sufficient size to resist displacement during peak flood events. The rock must be placed at the original watercourse bank grade to ensure there is no infilling or narrowing of the watercourse.
    • Fill material placed below the normal high water mark of the watercourse will be erosion resistant and/or protected from erosion.

Fish and fish habitat

  • The project must not be located within 100 metres of fish spawning or sensitive habitat if any in-water work is a requirement of the project.
  • Capture, relocate and monitor for fish trapped within isolated, enclosed, or dewatered areas. Dewater gradually to reduce the potential for stranding fish.

Construction and maintenance

  • The construction of arch culverts must not result in the alteration of the bed or banks of the watercourse or infilling or narrowing of the watercourse channel.
  • The crossing must be installed under low-flow conditions and not when flows are elevated due to local rain events or seasonal flooding.
  • The culvert must be secured on continuous footings outside of the normal high water mark and will be constructed according to the manufacturer’s specifications using materials that are appropriate for the site and expected loads.
  • Where footings are constructed with concrete, appropriate measures must be taken to ensure concrete materials do not encroach into the bed of the watercourse.

2.4 – water crossing standards for the construction of snow fill and ice bridge crossings

Snow fills and ice bridges, two types of water crossings that provide cost-effective access when lakes, rivers and streams are frozen, are typically used for temporary winter access in remote areas. Ice bridges are normally constructed on larger watercourses that have sufficient stream flow and water depth to prevent the ice bridge from contacting the stream bed or restricting water movement beneath the ice. Snow fills, however, are temporary crossings constructed by filling the channel of a watercourse with clean compacted snow.

General standards

  • The conditions and requirements of the general water crossing standards must be implemented in addition to, and in conjunction with, this water crossing standard.

Design and location

  • The work must not include dredging, placing fill, or grading or excavating the bed or banks of the watercourse.

Erosion and sediment control

  • No earth fill or aggregate is permitted below the normal high water mark of the watercourse. Crossings must be constructed of clean water, ice and snow that are free of dirt and debris.

Fish and fish habitat

  • Snow fills and ice crossings must not restrict water flow within the watercourse where it occurs naturally during winter conditions, or otherwise completely obstruct fish passage at any time.
  • The project must not be located within 100 metres of fish spawning or sensitive habitat.

Construction and maintenance

  • Appropriate seasonal conditions must be present (e.g. adequate depth of snow and ice, winter temperatures) to provide certainty that the construction and removal water crossing standards can be satisfactorily implemented.
  • Aggregate or loose woody material cannot be used to top the crossing.
  • If logs or corduroy are used to stabilize the approaches of ice and snow fill crossings:
    • The logs must be clean and securely bound together to facilitate removal and minimize site disturbance;
    • No logs or woody debris can be left within the watercourse;
    • Corduroy (if used) adjacent to the watercourse banks must be removed and placed outside the floodplain to help prevent a damming effect on the site. Corduroy that is frozen or embedded into the road approaches or watercourse banks must be left in place to reduce the risk exposing mineral soil adjacent to the watercourse. The remaining snow and ice can be left to melt in the spring. If required, remedial work will be carried out on the site after the crossing is removed to ensure that no logs or woody debris can wash back into the watercourse.
    • Logs may be placed on road approaches to assist in diverting runoff away from the watercourse; however, they must be placed outside of the floodplain and in such a manner as to ensure that they do not wash back into the watercourse.
  • Sanding of snow and ice crossings must be kept to a minimum and within the bounds of operational health and safety considerations.
  • Corduroy logs or brush mats must be installed on the approaches to the watercourse crossing when conditions are soft in order to avoid disturbing the banks and crossing approaches.
  • If water is being pumped from a watercourse to reinforce the crossing, the intakes must be sized and adequately screened to prevent debris blockage and fish entrainment.
  • Follow the DFO Interim code of practice: End-of-pipe fish protection screens for small water intakes in freshwater.

2.5 – water crossing standards for the construction of single, small closed-bottom round culverts

This water crossing approval specification applies to the construction of single, round, corrugated, closed-bottom steel, aluminum, or plastic culverts that are less than or equal to 1200 millimeters (4’) in diameter and do not require site-specific engineering approval (i.e., span less than three metres (9.8‘)), as per MNRF's Crown Land Bridge Manual, 2008.

General standards

  • The conditions and requirements in the general water crossing standards must be implemented in addition to, and in conjunction with, this water crossing standard.
  • The project does not:
    • Replace an existing open-bottom crossing (e.g. clear span bridge, arch culvert)
    • Replace an existing closed-bottom culvert that is larger in diameter than that being installed; or
    • Involve the installation of more than one closed-bottom culvert at the crossing location

Design and location

  • Culvert crossings must be located, designed and constructed to minimize the likelihood of ongoing outlet scour, culvert undermining and/or the erosion of fill in order to provide for stable and non-perched crossing sites that can provide for fish passage.
  • The culvert must not be located on meander bends, braided watercourses, alluvial fans, or any other area that is inherently unstable and may result in the alteration of natural stream functions or erosion and scouring of the crossing structure.
  • Culverts must be sized to a minimum Q25 design flow using MNRF water engineering/calculation software, or equivalent software programs deemed acceptable by MNRF.
    • In cases where an unmapped watercourse is encountered during the construction of a road, and where a proper watershed analysis cannot be completed to determine the Q25 design flow, the culvert must be sized to ensure that it spans from bank to bank within the watercourse.
  • Culverts must not be installed where the channel slope at the crossing location (i.e., physical rise over run of the culvert footprint prior to construction) is of a gradient greater than 2.0%.
  • Culverts must not be installed where the slope of road approaches or either of the bank approaches is greater than 30%/17˚.
  • Crossing locations must be selected where culverts can be embedded below the grade of the watercourse bed. The amount of embedment should be determined by local conditions.

Erosion and sediment control

  • Appropriate site-specific mitigation measures must be enacted to ensure the construction of the culvert crossing does not result in the ongoing erosion of fill. At a minimum, measures must include:
    • Both the inlet and outlet ends of the culvert must be stabilized with appropriately sized non-erodible material (e.g. rocks, cobble sized stones) to prevent erosion of the fill slope and the watercourse bed. Rock used to stabilize crossings and watercourse banks must be clean, free of fine materials and of sufficient size to resist displacement during peak flood events. The rock must be placed at the original watercourse bank grade to ensure that there is no infilling or narrowing of the watercourse.
    • Fill material placed below the normal high water mark of the watercourse must be erosion resistant and/or protected from erosion.

Fish and fish habitat

  • The project must not be located within 100 metres of fish spawning or sensitive habitat including Brook Trout spawning or upwelling areas.
  • The project must not be located on any watercourses or tributaries that flow into, and are within 500 metres, of known naturally reproducing brook trout lakes.
  • The combination of culvert size, length, slope and drainage area will not create accelerated water velocities that will consistently and predictably impede the passage of fish.

Construction and maintenance

  • The crossing must be installed under low-flow conditions and not when flows are elevated due to local rain events or seasonal flooding.
  • Both the interior and exterior of round, closed bottom culverts that are installed on waterbodies must be corrugated to ensure structural stability and facilitate fish passage.
  • The grade of the culvert must reflect the grade of the natural watercourse bed.
  • Backfill must be adequately compacted around the culvert. Only clean sand or gravel can be used as backfill and must be compacted around the culvert in layers.
  • Culverts must be the correct length to permit banks to be sloped at an angle of 2:1 or a stable angle of repose for the materials used.

2.6 – water crossing standards for the removal of single, small closed-bottom round culverts

This water crossing approval specification applies to the decommissioning of all round, closed-bottom steel, aluminum, or plastic culverts that are less than or equal to 1200 millimeters (4’) in diameter.

General standards

  • The conditions and requirements in the general water crossing standards must be implemented in addition to, and in conjunction with, this water crossing standard.
  • Removal of water crossings will only occur if it is consistent with the approved road use management strategy in the applicable FMP and is scheduled for removal in the current AWS.
  • If the construction of the crossing was originally reviewed and approved by MNRF and/or DFO, all applicable conditions of approval must be fulfilled.

Erosion and sediment control

  • Upon removal, the site must be stabilized and protected against erosion. Approaches to the watercourse should be stabilized at a 2:1 slope or stable angle of repose for the materials used using site appropriate methods.
  • All exposed soil must be seeded and/or stabilized immediately following completion of activities. Erosion and sediment control measures must be appropriate for the site conditions and maintained until vegetation has become permanently re-established within disturbed areas and/or exposed mineral soils have been stabilized with rip-rap or appropriately sized non-erodible rock material.
  • Materials removed or stockpiled during removal (e.g. grubbing, overburden fill) must be deposited outside the floodplain and stabilized/protected against erosion to ensure material does not enter the watercourse.
  • Surface water runoff and road approaches and ditches must continue to be directed away from the watercourse and into vegetated areas. Diagonal berms or waterbars must be installed where the erosion potential of the road approaches is likely to result in the road’s gravel surface and underlying fill being deposited into the watercourse over time. Sediment traps used within ditch lines adjacent to the watercourse crossing approach must be replaced and/or maintained to their original condition prior to the construction of the crossing.
  • Appropriately sized erosion-resistant materials must be used below the normal high water mark for stream bank rehabilitation.

Fish and fish habitat

  • Refer to part 1 of this section for general water crossing standards that apply to water crossings.

Construction and maintenance

  • The crossing must be removed under low-flow conditions and not when flows are elevated due to local rain events or seasonal flooding.
  • The watercourse must be restored as closely as possible to its original condition prior to the construction of the crossing, including retaining as close as possible the original stream alignment.
  • All crossing infrastructure must be completely removed from the site.
  • Grubbing must be minimized to leave as much of the existing vegetation intact.

Part 3.0 – water crossing construction and removal best management practices and mitigation measures

Introduction

The best management practices and mitigation measures outlined in this section are aimed at supporting proponents in meeting the requirements described in the water crossing standards in part 1.0 and 2.0 of this section. These best management practices and mitigation measures constitute a suite of planning, design, construction, maintenance and removal tools and approaches that can support proponents in the implementation of water crossing standards.

In many cases, the mitigation measures included in this section represent existing industry construction practices. In other cases, the mitigation measures represent best management practices that would provide an increased level of assurance that the water crossing standards will be met.

Additional direction is provided in Measures to Protect Fish and Fish Habitatand Standards and Codes of Practice on DFO's website may also apply. When applying a DFO Code of Practice, notification forms do not need to be sent to DFO. Notification will follow direction outlined in this Protocol.

Proponents have the flexibility to utilize any or all of the mitigation measures detailed below as site conditions warrant, recognizing that proponents are required to comply with the water crossing standards.

3.1 – crossing-specific design, construction and fisheries best management practices and mitigation measures

3.1.1 – clearspan bridges

  • Ideal site conditions for bridge construction include narrow water width, solid foundations for abutments, erosion-resistant soils and shallow water depths. A preferred site with these characteristics is a riffle or rapids section of a stream or river. These areas can also have a high value for fisheries, either as a spawning or feeding area and are also important for their recreational value and potential for historical or archaeological material.
  • Road fill can be kept from spilling into the water opening by using wing walls on bridges.
  • Concrete buckets, wheelbarrows, or shovels should not be washed in watercourses. They should instead be washed with hoses so that run-off is filtered through vegetation. Cement or fresh concrete are not permitted to enter waterways.
  • Treated wood contains toxic substances that must be controlled during installation around water. The following practices should be used when using treated wood:
    • Timber should be specified as free of surface oils and meet CSA Standard 080.
    • Timbers used below or near water level should be reasonably dry without surface oils. Those timbers with surface oils should be used at the back of the crib, above the normal high water mark and against the road fill.
    • Field cuts and drill holes should be done on land to keep chips and sawdust out of the water. When drilling over water, a vacuum should be used to collect chips and sawdust.
    • To prevent decay, field cuts and drill holes must be liberally painted with preservatives. Field applied preservative should be approved for domestic use (e.g. copper napthanate) and be applied following instructions on the container.
    • Field applied preservatives should be allowed to thoroughly dry before placement in water.
    • Waste pieces of treated timber must not be burned. The only legal and safe disposal is in an approved waste disposal site.
    • When building cribs, use an inside lining of planks or filler timbers to contain the crib fill material unless all of the fill is larger than the spaces between crib timbers.
    • Minimize spaces in bridge decks, and use curbs to prevent road gravel from falling into the water.

3.1.2 – snow fill and ice crossings

  • Choose an approach to snow fill construction that is appropriate for site and environmental conditions:
    • True snow fills are most typically used in association with ephemeral, intermittent and/or very small slow moving permanent watercourses. Clean snow is pushed into a waterway that has either frozen solid to the bottom or has ceased to flow during the winter months. The idea is to pass over the stream and not disturb the existing ice/snow cover on the stream and banks.
    • Snow fills can often be reinforced by freezing the clean snow as it is pushed into the waterway or by using a log fill approach whereby a layer of logs is built / corduroyed into the snow fill well above the ice level to both reinforce the snow and facilitate the movement of water in the event of seasonal winter thaws. Freezing of the snow as it is pushed will produce maximum strength and durability. The best freezing is achieved by compaction and by adding water.
    • When water flow on permanent watercourses is assumed or confirmed to be occurring under the watercourse ice, a culvert can also be placed on top of the frozen watercourse channel before building the snow fill to add further reinforcement to the crossing while also providing for the movement of water and/or fish in the event that a seasonal winter thaw occurs. In this case, cables are often attached to the culvert to facilitate its removal before the spring freshet.
  • Winter crossings should be located in low areas and where the approach roads have grades of 5% or less.
  • Approaches should be constructed using clean compacted snow and ice to a thickness that will protect the banks of the watercourse and the vegetation root mat (30 centimetres or more).
  • Dark materials should be kept away from the surface of the snow fill as they tend to thaw the road and could end up in the stream. For example, sanding trucks should minimize or avoid sanding the snowfill crossing, within the bounds of health and safety requirements. In these cases, signs should be placed on the road to mark out no sanding areas.
  • Ensure that erodible materials do not enter the water when the spring melt occurs.
  • Crossings should be rehabilitated before spring break-up. Keep a close watch on weather conditions near the end of the winter to ensure sufficient time for removal before the ground softens. It is better to remove a crossing earlier rather than take the risk of running out of time due to an early spring.
  • When the crossing season is over and where it is safe to do so, a v-notch can be created in the centre of the ice bridge to allow it to melt from the centre and also to prevent blocking fish passage, channel erosion and flooding. Compacted snow should be removed from snow fills prior to the spring freshet.

3.1.3 – round culverts

  • The preferred characteristics of a culvert water crossing site are different than those for a bridge. Conditions favorable for culvert installation include:
    • Little or no curve in stream as it reaches the culvert, so the straight pipe will fit the channel and reducing debris backing up at the curve, blocking the opening.
    • A fine grained substrate to provide suitable bedding (gravel or finer).
    • A stable foundation that will not significantly settle when the fill is added.
    • No bedrock or large boulders that will prevent setting the pipe into the streambed.
    • Narrow water surface width (less than 3 metres).
    • Streambed slope is less than 2%. Culverts are not recommended in streams with >2% slope and are most suitable in slow moving streams with fine bottom sediments.
    • A shallow stream with a water depth of less than 1.5 metres.
  • Culverts should be installed to ensure that they are not, or will not become, perched and impede the free passage of fish. Best management practices and mitigation measures include:
    • Crossing locations should be selected where culverts can be embedded below the grade of the watercourse bed to support the free passage of water and fish, enable natural watercourse substrate to fill in within the culvert, and reduce the likelihood of outlet scour and undercutting at the crossing site. The amount of embedment should be determined by local conditions, however, a minimum of 10% embedment is recommended.
    • During installation, the proponent should evaluate the site and recognize the potential for embedment challenges or the likelihood of long- term erosion of the watercourse bed downstream of the culvert location.
    • Unexpected site conditions (e.g. the presence of a large boulder or bedrock) does not negate the need to ensure fish passage through the culvert. Where site conditions will not allow for a minimum of 10% embedment, the proponent should consider alternative crossing locations or structures (e.g. from a round culvert to a bottomless arch culvert or a clearspan bridge).
  • Culverts should be installed/embedded to ensure that a minimum of 20 centimetres of water passes through the culvert during low-flow periods of the year, where it would occur under natural conditions, to enable year-round fish passage.
  • The installation of the culvert must not create flow velocities that surpass the swimming abilities of the watercourse’s fishery. One or more of the following measures and practices can be utilized:
    • Culvert flow estimating software and procedures to predict the potential flow velocities passing through the culvert,
    • Predicted velocities can be considered relative to distance and fatigue swimming curves (e.g. accessible from SPOT: Swim Performance Online Tools available or in scientific literature) for the species of fish potentially affected by the project,
    • In cases where velocities are likely to exceed the swimming abilities of the species of fish in the watercourse, particularly at critical life stages where migration is expected to be occurring (e.g. spawning periods), the crossing should be re-designed to reduce the expected velocities passing through the culvert (e.g. select a different crossing location, consider larger diameter and/or shorter length culvert, install baffles to create resting pools within the culvert, utilize alternative clear-span crossing structures).
  • Culvert diameter is determined by hydrology analysis, with the ultimate size of culvert being selected to ensure that normal water level rises no higher than half the diameter of the pipe and no higher than the top of the pipe at the design flood flow.
  • The constriction caused by a culvert should not cause significant upstream back-flooding.
  • Select appropriate lengths of culverts to keep road fill from spilling into the water opening.
  • Culvert installations during winter/frozen conditions should be avoided in order to ensure that construction water crossing standards continue to be met post-construction and the culvert installations remains safe and stable. For example, there is a higher likelihood of backfill installed during winter/frozen conditions settling or shifting upon thawing and creating conditions of culvert undermining and structural instability.
  • Where site conditions warrant, consideration should be given to proactively installing beaver deterrents at the end of culverts during construction as an approach to mitigate potential future beaver activity and possible failure of the crossing/road.
  • Culverts are to be inspected/monitored more regularly for blockage in areas where the presence of beavers are known to occur or floating debris is known to be significant.
  • The culvert should be installed on a flat gradient.
  • Erosion should be controlled with stable trimmed slopes (e.g. use rip rap).
  • A protective erosion resistant capping should be placed on fill slopes around the culvert inlet and outlet. Acceptable materials include coarse clean gravel, boulder rip rap, blasted rock rip rap, and vegetation.
  • Where flow exiting a culvert may scour the streambed, an erosion resistant rip rap apron should be placed in the streambed. Streambeds with steeper slopes are especially vulnerable. The apron should extend up to six culvert diameters beyond the end of the pipe and it should have a “V” shaped cross section to allow fish migration in low water.
  • Before equipment moves away from the water crossing a formal inspection should be made by supervisory staff to confirm the mandatory water crossing standards are met. The cost to correct deficiencies is much lower when equipment is on site.
  • In the construction of some water crossings a temporary diversion of flowing water may be needed so the crossing structure can be built under dry conditions. Working in dry conditions can increase the likelihood of a successful installation while significantly reducing the amount of sediment produced during the work, and as such, should be considered in cases where installation activities will take more than a few hours or where site conditions (e.g. bed substrate) will likely result in significant sediment being released into the watercourse. In order to attain dry conditions partial or complete diversions can be constructed. Partial diversions consist of cofferdams which block the flow in a portion of the stream and pumps to keep the work area dry. Complete diversions direct stream flow through pumps, pipes or into a new temporary channel.
  • Once the crossing is installed the natural channel is re-watered and water flows through the new structure. Best management practices for temporary flow diversion include:
    • In cases where water will be partially diverted or removed to allow for dry installations, the appropriate MNRF office should be consulted to ensure that any additional necessary permits are attained prior to work commencing (e.g. license to collect fish).
    • The selection of the dam and pump stream diversion method or the bypass channel method depends on the stream flow and how long the diversion is needed. Dam and pump stream diversion is effective for small streams and can be used during the closed season for applicable in-water timing windows.
    • Sufficient waterway size must be provided for the diversion to pass floods expected during construction. Suggested design flows for different lengths of time are:
      • Less than one week - use observed flow x2, if no rain is forecasted or;
      • More than one week (but not during the spring) - design for the 2 year flood.
    • In-stream cofferdams should be constructed using erosion-resistant material such as rock fill, coarse rip rap, sandbags, precast concrete blocks, water-inflated bladders or sheet piling.
    • In-stream sediment control techniques such as stake silt fences or floating silt curtains to isolate working equipment from shallow open water are to be used. These fences are often improperly installed and should not be placed across streams where there is discernable flow as it will block flow and lead to erosion or failure.
    • When excavating a bypass diversion channel, work in dry conditions where possible, begin at the downstream end and move upstream. The diversion channel should have gentle curves and be at the same approximate slope gradient as the natural stream.
    • Diversion channels are used in larger streams or when the isolation must be in place for more than a few days.
    • Sandbags at the upstream end can be used to direct flow into diversion channel.
    • Shallow water flow may be permitted to pass through the work area on clean rock.
    • Old culverts may be used as a bypass pipe.
    • The newly excavated temporary bypass channel should be protected with an erosion-resistant lining (e.g. geotextile or channel liner erosion control blanket). The lining can be held in place with gravel piles, stones or stakes to keep water from getting underneath.
    • The point where the old and new channels meet will be very susceptible to erosion. Vulnerable areas can be protected with erosion controls and energy dissipating measures.
    • When pumping water, a screen should be used on the intake pipe to keep fish out and the outlet should discharge water on land to naturally remove sediment from the turbid water.
    • All diversions must be removed upon completion of the crossing.
  • If culverts are built on soft material, granular bedding shaped with a camber is recommended so that when settlement occurs the pipe will continue to function.
  • Prefabrication of a culvert or bridge crib on land is encouraged to reduce the time in-stream. The prefabricated sections are then lifted into position.
  • Blasted rock used in water should not generate acid or other toxic trace elements (e.g. arsenic). In areas where acid generating rock is a concern, the proposed material should be tested before using in water.
  • If conditions permit and/or are warranted, a dip should be built in the road or install overflow/drainage culverts installed to allow water spillage over the road if the pipe is blocked or its capacity is exceeded. This would also lower repair costs and reduce environmental damage in case of a washout. The dip should be on the far side to ensure access to the culvert for maintenance.

3.1.4 – non-road water crossings-equipment only

The following water crossing mitigation measures and best practices apply to the construction of non-road forestry water crossings typically involving the use of operational forestry equipment such as fellers, bunchers, skidders, and forwarders.

Many watercourses, including permanent and/or intermittent streams with defined channels, as well as ephemeral surface/shallow ground water flows (e.g. swales, seeps), are encountered by forest harvesting equipment during operations. These watercourses should be avoided and considered as they may be considered fish habitat.

These best management practices are intend to supplement related operational considerations found in Ontario’s forest management guides, and the numerous resources available to support practitioner’s efforts to distinguish the differences between permanent/intermittent streams and ephemeral surface/shallow ground water flows, such as MNRF's Stream Permanency Handbook for South-Central Ontario (2013).

This Protocol does not mandate any requirements for non-road water crossings. It remains your Duty to Notify DFO if you have caused, or are about to cause, the death of fish by means other than fishing and/or the HADD of fish habitat. This obligation extends beyond notification to taking corrective action and reporting to DFO. Such notifications should be directed to Contact the Fish and Fish Habitat Protection Program.

The following best management practices for non-road water crossings have been developed to support decision making during operations and serve as a means to facilitate compliance with the Fisheries Act:

  • Appropriate and site-specific measures should be taken to avoid disturbing watercourses, ephemeral surface, and shallow groundwater flow in such a way that disrupts their hydrological function by impeding, accelerating or diverting water movement.
  • The project must be compliant with applicable water crossing standards and guidelines in the most recent versions of Ontario’s forest management guide(s) that address the conservation of biodiversity at the landscape scale and the stand and site scales.
  • Unless required by the FIM (e.g. discovery of a new unmapped value) or specifically by an approved FMP, there are no reporting requirements for the construction of non-road operational forestry water crossings.
  • Although equipment-only non-road forestry water crossings are highly temporary and typically don’t span great lengths, the proponent should consider implementing the requirements of water crossing standards found in this Protocol as an approach to help promote compliance with the Fisheries Act.
  • Crossing through watercourses and ephemeral surface/shallow groundwater flows with forestry equipment should be avoided as often as possible. Where crossings cannot be avoided, clearspan skidder bridges/pads or native timber bridges built to satisfy occupational health and safety requirements are preferred crossing structures and are recommended for use in as many cases as are operationally and economically feasible.
  • Where crossings are necessary, the number of crossing locations should be minimized and chosen strategically to reduce the potential damage to channel banks and beds and the hydrological function of the feature.
  • Crossing locations should be selected where the approach slopes and watercourse grades are as small as possible.
  • Crossing approaches should be installed as much as possible at right angles to the watercourses.
  • Disturbance to the banks of watercourses and the hydrological function of aquatic features should be kept to a minimum with the installation of brush mats, swamp mats, corduroy or snow/ice on the approaches to the crossings.
  • Ground disturbance at the crossing location should be kept to a minimum and as much adjacent vegetation as possible must be retained.
  • Ruts caused by machinery within the approaches to the crossing should be rehabilitated following the completion of operations to ensure that surface water runoff is diverted away from the watercourse channel. Rehabilitation of ruts should be conducted in a way that does not increase the amount of damage or hazard to the watercourse channel.
  • Operational debris or mitigation measures that were implemented such as brush/swamp mats or corduroy should be removed from the watercourse channel or ephemeral surface/shallow groundwater flows to ensure that natural drainage patterns are maintained.

3.2 – general design, construction and fisheries best management practices and mitigation measures

3.2.1 – general best management practices and mitigation measures

  • Develop a construction strategy for every water crossing so everyone involved knows the risks, the details about how it will be built, and the measures needed to comply with the approval criteria.
  • Approach fills to the water crossing should be built by end-dumping to minimize the need to remove the ground cover vegetation. Try to maintain as much vegetation as possible to reduce future erosion risk. The removal of stream boulders for rip rap is not acceptable except where it is necessary to set a culvert at the correct elevation.
  • All construction material and equipment should be at the construction site prior to beginning in-water work in order to reduce the in-water disturbance time.
  • Equipment and material piles are to be stored and stabilized in a manner that prevents them from entering any watercourse.

3.2.2 – cumulative effects best management practices and mitigation measures

  • The number of water crossings should be minimized to support the management of the potential cumulative impacts of forest water crossings on fisheries and aquatic environments. Every effort should be made within the bounds of realistic operational, safety, and economic considerations to minimize the number of new water crossings.
  • Existing trails, roads, or cut lines should be used wherever possible to avoid disturbance to watercourse banks and the riparian vegetation.

3.2.3 – design flow best management practices and mitigation measures

  • Industry infrastructure can be protected and the potential environmental impacts of crossing failures minimized in the face of increasing frequency and intensity of extreme rain and weather events by using larger design flows (e.g. Q50, Q100) for culvert crossings, particularly on longer term roads such as primary and branch forestry roads. In these cases, appropriate watershed analyses and construction techniques (e.g. culvert embedment) should be undertaken to ensure that a minimum wetted area within the culvert is maintained during low flow periods of the year to allow continued fish passage through the crossing.

3.2.4 – crossing location best management practices and mitigation measures

  • When selecting a crossing location:
    • Select a straight stretch having a single channel with stable streambed and banks.
    • Design and construct approaches so that they are as perpendicular as possible to the watercourse. This will simplify culvert or bridge construction and minimize the loss or disturbance of riparian vegetation.
    • Choose a site where the road approaches are favorable and earth cuts are not required within 100 metres of the water’s edge.
    • As site conditions permit, avoid ditching road approaches within 30 metres of the crossing site to avoid funneling sediment-laden rainwater directly towards the watercourse.
    • If possible, avoid areas of wide water or very deep water (i.e. more than 1.5 metres deep) to avoid the potential construction challenges associated with larger and longer water crossing structures.

3.2.5 – deleterious substances best management practices and mitigation measures

  • The Fisheries Act prohibits the deposition of deleterious substances into water frequented by fish. General mitigation measures to help satisfy this prohibition include:
    • Prior to moving equipment to the water crossing, wash equipment to remove leaked petroleum products and prevent the introduction of invasive species.
    • Repair equipment before construction to minimize leaks.
    • Keep an emergency spill kit on site in case of fluid leaks or spills from machinery and be prepared to use petroleum-absorbing “diapers” if necessary.
    • Locate refueling areas and hazardous material containment areas away from streams and other sensitive areas.
    • Establish appropriate areas for washing concrete mixers, and prevent concrete wash water from entering rivers and streams.
    • Take steps to prevent leakage of stockpiled materials or project spoil into streams or other sensitive areas (e.g. locate the stockpiles and spoil piles away from watercourses and other sensitive areas, use sediment traps, cover during heavy rains).
    • Control materials on the jobsite so that loose boards, nails, and other debris will not enter the waterway and flow downstream. A boom should be used downstream of the project if there is a chance that debris could enter the water.

3.2.6 – temporary fords best management practices and mitigation measures

  • Consider the following best management practices and mitigation measures if there is a need to ford the watercourse to temporarily access the far side and enable construction/removal activities to proceed:
    • Ford the stream at only one location where the best conditions exist. Sites favorable for a ford are those where:
      • the banks are low and the stream is shallow
      • there are no spawning sites at the crossing or downstream that could be impacted
      • the streambed must carry the equipment load, therefore, firm rock, boulder or coarse gravel bottom is best
      • the water depth should be less than one metre (for work and equipment safety)
      • construct crossings at right angles to the stream to have the shortest length of impact
      • if possible, locate the ford on a section of the stream that would be altered during the water crossing construction
      • limit the number of equipment crossings on the ford to one time per piece of equipment
      • equipment crossing the ford should be clean of mud and be mechanically sound with no oil or gas leaks
      • if equipment will be working in-stream keep the amount of time in-stream to the bare minimum required and install an oil absorbent boom across the stream in a quiet area downstream in case of an oil spill

3.2.7 – erosion and sediment control best management practices and mitigation measures

Every site is unique and it is important that the most applicable erosion and sedimentation control techniques are selected to meet the needs of the site. It is critical to evaluate drainage patterns, soils, and construction activities to develop a customized approach for that site. The following erosion and sedimentation techniques are not exhaustive but offer a substantive list of possible options to consider in isolation or in combination with one another to help manage various potential site-specific sediment and erosion challenges.

  • Determine the project’s risk of sediment entering the water by considering:
    • off-land erosion risk: topography, soil type, soil exposure, time until protected
    • instream erosion risk: water depth, flow velocity, soil type, degree of isolation from open water
    • ease or difficulty of erosion and sedimentation control for the given design
    • materials available to work with
    • possible weather conditions, and
    • staff competence and compliance monitoring effort
  • Establish the consequences of sediment in the water, considering:
    • how close to the in-water timing restrictions is the scheduled work
    • how far downstream the sediment could move (potential zone of impact)
    • whether there are fish habitat values within the deposition zone that could be affected
    • whether sediment from construction is compatible with natural stream sediments and channel morphology
    • sediment transport capability of the stream
  • The seriousness of the expected short-term or long-term change due to sediment.
  • During the construction phase, workers are expected to follow the strategy developed in project planning but also be prepared to deal with changes and make improvements where possible.
  • Ensure that sediment control structures are maintained and that excess accumulated sediment is removed and stabilized above the normal high water mark.
  • Supervisors should conduct inspections to ensure compliance with the mandatory water crossing standards.
3.2.7.1 – administrative considerations

Administrative considerations can help ensure erosion and sediment control objectives are met. They cost little or no extra money and are aimed at ensuring operations are always under control.

Best management practices and mitigation measures
  • Clearly assign responsibility to specific individuals who are made accountable for erosion and sediment control. Their role will be to inspect, maintain, and respond to changing conditions on the project.
  • When working around water, it is preferable to have workers who are experienced with the working conditions and familiar with regulatory requirements.
  • Water crossing planning should address erosion and sediment control and include ideas from equipment operators and on site supervisors.
  • Do contingency planning to anticipate “worst case” scenarios, like a heavy rainstorm, and have the materials readily available to respond accordingly.
  • Schedule work for dry weather periods and delay work if long periods of heavy rain are in the forecast.
3.2.7.2 – slope stabilization

Slope stabilization consists of trimming the slope flatter than the angle of repose of the material to increase the chances of early re-vegetation. A steep cut or fill slope of mineral soil will erode because the particles are unstable and unable to hold vegetation.

Flattening a steep slope involves adding fill or taking out additional cut material. For example, an earth cut slope in sandy material excavated at 1H:1V would be unstable and be subject to an erosion problem. Flattening the same slope to 2H:1V or flatter will result in better stability and quicker re-vegetation. Once a stable angle of repose is reached there is little benefit of further flattening: this will just increase the area of soil exposed to erosion.

Best management practices and mitigation measures
  • The best time to flatten slopes is during the initial rough grade construction.
  • Flatten slopes to a stable angle of repose.
  • Although a steep cut can be trimmed back economically it is very costly to flatten an existing road fill that is too steep. It is best to construct stable fill slopes from the beginning of construction rather than trying to correct them once the road is built.
  • Round off the corners to reduce erosion at sharp grade changes.
  • Graded areas can be roughened to slow down water and reduce the risk of gully erosion by using a bulldozer or other tracked machine to walk up and down the slope leaving a pattern of tread imprints parallel to slope contours. The tread indentations trap seeds, hold moisture, and encourage plants to become established. The tracks also introduce roughness and slow the velocity of sheet flow.
3.2.7.3 – rip rap

Rip rap is a layer of coarse erosion resistant material used to cap and protect the underlying mineral soil from erosion. It also slows down the flow of water by presenting roughness in the water’s path. This reduces the erosive forces acting on the soil and provides a lining of stable material too large for the water to displace. The reduced flow velocity encourages water infiltration into the ground and eventually vegetation will grow between the rip rap particles if soil is close to the surface.

Rip rap can be used on any exposed mineral soil subjected to flowing water where the velocity of water flow, seriousness of erosion, steepness of slope, or material type prevents satisfactory establishment of vegetative cover. Some form of rip rap is normally used at all water crossings where fills are exposed to stream flow (e.g. at culvert inlets or bridge abutments). It can also be effective in lining ditch bottoms to prevent erosion. Boulders from a borrow pit are the most common rip rap on access roads.

Although quite effective, the treatment can be expensive especially in some areas of Ontario where there are neither rock cuts nor suitable pit boulders close by. In these areas, a cover of dense vegetation may be an attractive alternative.

Best management practices and mitigation measures
  • Surface grading of the surface to receive the rip rap layer is important. Slopes should be shaped to steepness no greater than 2H:1V.
  • At water crossings ensure the rip rap extends down the slope for stability reasons.
  • The protection should also extend up the slope above the expected high water level in a flood.
  • Consider the possible installation of a non-woven geotextile fabric used under rip rap to prevent soil movement out though the rip rap. There are several options when selecting the type of erosion control geotextile to place under rip-rap. Multiple factors must be taken into consideration. The soil type and its percentage of fines play an important role in choosing the correct geotextile. The weight and angularity of the rip-rap and the height at which it is dropped will determine the required geotextile strength. Finally, anticipated water flow should be considered. Installation of geotextiles should follow manufacturers’ recommendations.
  • Select an appropriate rip rap material based on local availability and where the rock must be used.
  • Do not use mine slag or rock that generates acid or other toxic trace elements (e.g. arsenic) near water crossings.
  • Boulders may be the easiest to obtain, but they tend to roll on each other; therefore, a flatter slope will be necessary than would be the case if blasted rock were available. Boulders can be separated from pit run gravel with the backhoe teeth or with a screening plant (e.g. grizzly bars).
  • Blasted rock fragments available from rock cut areas make the best rip rap material because their rough angular shape prevents them from shifting and they can be made to the desired particle size.
  • Rip rap linings can be made to withstand most velocities if the proper size of rock is selected. The size of rock needed depends on the active force of flowing water. Larger rip rap is needed in faster moving water (blasted rock is the best material to use against channel flow).
  • Rip rap should be leveled and packed to a uniform layer, approximately twice as thick as the average particle size.
3.2.7.4 – seeding

Vegetation provides effective protection against erosion and sediment transport. Soil erosion only occurs in areas not protected by vegetation. Re-vegetation will occur naturally as wind-carried seeds blow onto the soil. However, techniques such as seeding, mulching, and fertilizing will speed up the growth process and improve the chances of success for short-term erosion control while the plants become established (see 3.2.7.5 on soil coverings).

A variety of seed is available to protect soil from erosion. Planting several plant species rather than a single type will increase the chances of success. In northern Ontario, mixes developed and specified by TransCanada Pipelines and the Ontario Ministry of Transportation have proven successful. These can be purchased from local seed supply stores. Some seeds are preferred for wildlife habitat (e.g. clover) and this may be a consideration in selecting seed. In all cases, seeding should only be considered when there is enough growing season remaining for significant root growth; otherwise, alternative erosion and sediment control measures and practices should be implemented.

Best management practices and mitigation measures
  • Evenly distribute seeds and ensure contact with the soil.
  • Cover seeds with a shallow layer of soil (10 millimetres thick) for best results.
  • Seed small areas, such as water crossings, by hand or with a hand-operated broadcast seeder.
  • Seed by hand after each water crossing is done rather than waiting to seed everything at once at the end of the road project.
  • Plant seeds when temperatures, moisture, and sunlight are moderate, usually in the spring and fall.
  • Hydro-seeding and mulching are cost efficient for large areas. It is a one step process for spraying a slurry of seed, fertilizer, mulch, and water. The critical factor in hydro-seeding is the ability of the spray to adhere to the soil and hold the seed in place during rainfall and wind.
  • Apply fertilizer according to the manufacturer’s instruction and prevent it from entering a watercourse.
  • Monitor plant growth and apply seed a second time in any bare spots.
3.2.7.5 – soil coverings

Soil coverings are materials placed over exposed mineral soil to give immediate, short-term protection while vegetation becomes established. Instead of striking the soil directly, the raindrop impact is absorbed by the covering. Soil coverings also assist seed germination by providing shade, moderating soil temperature, shielding germinants from wind, and reducing evaporation losses. Soil covers are justified where the consequences of short-term erosion are serious and must be controlled during the time it takes for vegetation to become established (e.g. near water crossings). Soil coverings commonly used on access roads include slash mulch, black organic material, and manufactured erosion control blankets.

Organic mulch

Organic mulch is an effective low-cost treatment for access roads because the raw materials are readily available. Slash and organic mulch have the further advantages of retaining moisture and providing nutrients.

Best management practices and mitigation measures
  • Trim slope to a stable angle prior to proceeding. Spread organic material and slash debris (e.g. sticks, roots, small vegetation, and wood chips) from the nearby bush on the exposed soil in a thin layer about 15 centimetres thick.
  • When available, use organic material from near the work site. In some areas the material may have to be trucked from offsite.
  • Work mulch into the mineral soil with a backhoe bucket or by tracked equipment traveling over the area. Ideally the sticks would embed in the mineral soil.
  • Seed the treated area with a mixture of different seeds, as described in 3.2.7.4.
  • Monitor the area for successful vegetation coverage.
  • Reseed bare areas to ensure full coverage of vegetation.
Erosion control blankets

Erosion control blankets are an effective soil covering that is widely available and easily installed without heavy equipment. Blankets provide immediate short-term protection while vegetation becomes established underneath. The selection of which blanket to use depends on the slope angle, the blanket life span, cost, and the risk the road designer is prepared to take.

Suppliers of these blankets provide design assistance to select which of their products should be used. Some products have biodegradable netting and some blankets can be pre-seeded by the manufacturer. The latter type should still be hand seeded with a proven local seed mix before the blankets are installed.

Best management practices and mitigation measures
  • Trim the slope to a stable angle and seed the area before laying down the blanket. The seeded vegetation will be able to grow through spaces in the material.
  • Install the blankets by rolling them over the seedbed down the slope in the direction of water flow.
  • Anchor the top of the blanket in a shallow U-shaped trench beyond the top of the slope.
  • Do not stretch blankets; rather allow them to lay loosely on the soil surface to achieve maximum soil contact.
  • Overlap joints in the downstream direction so flowing water does not lift them. A 30 centimetres overlap is recommended.
  • Be sure to select an appropriate blanket type based on slope.
  • Anchor blankets to the ground with 15 centimetres long wire staples or wood or plastic pegs. Consider using Biodegradable pegs. The staple frequency should follow the manufacturer’s instructions.
  • On frozen ground, use boulders instead of staples to anchor the blankets.
  • Inspect the erosion control blankets periodically, especially after rainstorms, for erosion, undermining or blanket displacement by wind. Repair any problems as quickly as possible.
3.2.7.6 – check dams

Check dams are overflow weirs placed across ditches to prevent erosion by reducing flow velocities and by creating an upstream pond where some coarse suspended sediment will deposit. They are used in long, steep roadside ditches where diversions into shrubs or treed area are not possible. Check dams allow for runoff to be stepped down the sloping ditch in a controlled manner. Their use is a short-term erosion prevention measure until vegetation becomes established for permanent erosion control.

Best management practices and mitigation measures
  • Check dams can be constructed using a variety of erosion resistant material such as blasted rock, boulders, sandbags, gabions, logs, or wood planks.
  • Do not use silt fences as dams in ditches (they are not strong enough).
  • It is important to properly embed the dam 15 centimetres or more by digging a trench to prevent flow under the dam. In cross-section the check dam should be “V” shaped with the sides rising above flood levels to avoid flow washing around the edges through the native soil.
  • The maximum height of a check dam is 60 centimetres and the centre should be at least 15 centimetres lower than the outer edges.
  • The spacing of check dams in a ditch should be close enough that the head pond of one dam reaches the toe of the next upstream dam.
  • Accumulated sediment should be removed when it reaches half the dam height, if erodible soils still exist upstream.
  • The drainage area of the ditch being protected should not exceed 4 hectares.
3.2.7.7 – brush barriers

Brush barriers are piles of slash debris (logs, limbs, tops) placed in the path of flowing water to provide immediate short-term erosion control by covering the soil and filtering sediment laden water. They reduce flow velocity and thus trap sediment in the branches and limbs. Brush barriers can trap 80% of suspended sediment entering them. Brush barriers are normally used at the toe of fill slopes near a water crossing.

Best management practices and mitigation measures
  • Position a large anchor log at the toe of the fill, parallel to the direction of the road.
  • Secure the anchor log in position by placing it against stumps, rocks or trees.
  • Place stockpiled slash (not exceeding 15 centimetres in diameter and 4 metres in length) on the fill slope above the anchor log.
  • Do not include stumps in the slash.
  • Compact the windrow of slash by tamping it with the excavator bucket. This produces a relatively dense windrow embedded in the surface to prevent flow under it.
3.2.7.8 – silt fences

Silt fences are lightweight structures suitable for filtering small volumes of water flow associated with small drainage areas. They are installed in the path of overland flow to reduce velocity and create a short shallow pond where some sediment will deposit. They act like a strainer allowing water to seep through while sand and larger particles are trapped in an upstream pond or on the surface of the fence. They are also used to define the boundary between disturbed soil and vegetative buffers.

Silt fences are relatively inexpensive devices and are made of either woven or non-woven geotextile material. A woven product especially fabricated for silt fencing is widely used. It is the proper height with pre-fastened wood stakes and a flap for embedment.

Silt fences are commonly used in developed areas. Their use is not as preferable on forest access roads because they are constructed of non-biodegradable materials and regular maintenance is required to ensure they function properly.

Best management practices and mitigation measures
  • The silt fence should be installed as early as site conditions permit, preferably before construction exposes mineral soil.
  • Locate the silt fence in one of three areas: a short distance out from the toe of an embankment slope, along the bank of a sensitive stream, or at the downstream end of an erodible earth cut area.
  • The area draining to the barrier should be small; typically less than 0.5 hectares.
  • The recommended distances between silt fences placed parallel to the contours on slopes are: 15 metres apart on a slope of 2H:1V; 25 metres on 3H:1V; 40 metres on 4H:1V, and 50 metres on 5H:1V. Silt fences should not be used on slopes steeper than 2H:1V.
  • Locate the silt fence so there is a flat area upstream where water can pond against the fence and allow suspended sediment to settle out.
  • Drive vertical wood or steel posts into the ground. Maximum post spacing without wire mesh is 2 m and with mesh support is 3 metres.
  • Fasten the geotextile fabric on the uphill side of the posts.
  • Anchor the geotextile in a trench 10 centimetres in depth and width to toe-in the silt fence and prevent undermining.
  • Inspect silt fences after each rainfall.
  • Damage such as end runs, overtopping or undercutting should be repaired quickly.
  • When a fence is half full of sediment it needs to be cleaned out.
  • Silt fences should not be placed across a ditch or in a drainage path that carries high volume or high velocity flow where washout could occur.
3.2.7.9 – sediment traps

Sediment traps are used downstream of erodible soil sites and consist of sumps and ponds created in the path of flowing water to reduce the velocity and cause deposition of suspended soil particles. Generally, only the larger suspended material (sand and gravel) settles out. An effective trap can retain no more than 50% of the sediment carried into it. They are intended as temporary measures until more permanent controls stop the erosion at its source.

Best management practices and mitigation measures
  • Locate the trap close to the source of the sediment, preferably in a natural low area.
  • Do not use sediment traps in catchment areas greater than 1 hectare or locate the trap in a watercourse.
  • Construct the trap by excavating a hole in the ground or by creating an impoundment with a low head dam.
  • The trap size and the spacing between traps should be selected so that sediment from expected erosion areas fills the traps about the same time that vegetation is re-established to prevent further erosion.
  • Ensure that the trap is large enough for particles to settle. Often turbidity caused by water entering the trap does not allow particles to settle before the water in the trap overflows.
  • An initial trap capacity should be 250 m3 for every hectare of exposed catchment area.
  • The length to width ratio of the trap should be 2L: 1W or longer.
  • The outlet end of a sediment trap should be protected against erosion since it acts as an overflow weir.
  • Accumulated sediment should be removed to make room for the next rainstorm, if erodible soil exists upstream. They should be kept away from stream banks to reduce disturbing the riparian zone.
3.2.7.10 – forest floor filter

The natural undisturbed forest floor, with its organic litter and vegetative material, can filter sediment-laden water and trap suspended particles before they enter a watercourse. To be effective, there should be sufficient length of filtering material.

This technique is often used with ditch blocks and cross culverts on the approaches to water crossings so turbid runoff does not flow down the ditch and stream bank into the water directly. Although this technique works well for short-term filtering and sediment entrapment, site stabilization at the erosion source is needed to prevent a chronic problem.

This treatment may require construction of a cross culvert, an earth diversion berm across the ditch (ditch block) or excavation of a channel to carry water to the edge of the right-of-way (offtake ditch or ditch turnout). A diversion berm is different from a check dam because water is diverted out of the ditch and not allowed to flow over the berm.

Best management practices and mitigation measures
  • The drainage area of diverted flow at one location should be less than 2 hectares.
  • Where used, it is important to determine that the water will drain away from the road at a slope of at least 1%.
  • Berms should have a top width and height of at least 50 centimetres and side slopes of 2H:1V or flatter.
  • Since the diversion berm will be redirecting flowing water, the upstream surface must be resistant to erosion from the expected flow velocities.
  • The recommended spacing between ditch outlets depends on the slope of the ditch and the sensitivity of the soil to erosion.
  • The required length of forest floor filter depends on the ground slope. Use 30 metres of forest floor for slopes less than 15% and up to 90 metres for steep slopes.
  • Ditch channel, berm dimensions and outlet channel must be of adequate size to handle expected flow, including flood flows. If not properly sized the berm will overtop and flow will continue down the ditch line. In directing flow to the bush be careful not to cause gully erosion down steep erodible banks. If possible, water should be spread out when it leaves the right of way rather than be concentrated.