Specific Standards and Best Practices:
Stream Crossings

Table of Contents

Background

A stream crossing refers to a structure such as a clear span bridge or culvert used for road, driveway, pedestrian, livestock, or utility service crossing of a watercourse.

Private stream crossings are usually smaller in scale than public stream crossings (e.g., a livestock or driveway crossing) and are often constructed by an individual landowner.

Public stream crossings are usually larger in scale than private stream crossings (e.g., major road crossings) and may result in larger potential impacts to riparian and aquatic habitats.

Utility Crossings include service pipelines, pipes, cables and wires. Examples include sanitary sewer, electricity, telephone, and gas services. In addition to the potential impacts associated with the stream crossing, there is an increased risk of impact associated with the discharge of a deleterious substance carried by the utility (e.g., raw sewage, natural gas).

Winter Road Crossings include ice bridges, winter fords or snowfills constructed to provide temporary seasonal stream crossings.

Temporary Fords are temporary stream crossings installed to allow transportation or material movement across a channel for a limited period of time. Temporary fords have limited applicability, and increased risk to habitat and water quality may result if this crossing type is improperly located or constructed.

Stream crossing works are undertaken for a variety of reasons: to construct a crossing where no crossing existed previously; to replace an existing crossing with one of equal size; or to replace an existing crossing with a larger one or a different type of structure. Because of the risks to riparian and aquatic habitat and species, stream crossing works should only be considered when the need for the works can be justified:

For a new crossing – the area the crossing will provide access to is currently isolated, and the increased use of the area will not result in the degradation of aquatic and riparian habitat;

For a replacement crossing – the replacement is required to maintain access and safety, and the maintained or increased use of the area will not result in the degradation of aquatic and riparian habitat;

For enlargement of a crossing – current zoning permits the enlargement, and the maintained or increased use of the area will not result in the degradation of aquatic and riparian habitat.

Objectives

The Ministry’s objective for the management of stream crossings is to prevent harmful impacts to water quality, channel hydrology, riparian and aquatic habitats, and fish and wildlife species during crossing construction, modification, and deactivation activities.

Standards for Stream Crossings

All stream crossing works for which you are submitting instream works notifications or approvals must be compliant with the General Standards as listed in the Standards and Best Practices section of this document for:

• Compliance with Other Legislation;
• Land Ownership;
• Public safety;
• Completion of work ;
• Protection of water quality;
• Protection of Species and Habitat; and
• Protection of other water users.

Specific Standards associated with this type of work (Water Act Regulation Section 44(1)) authorize stream crossing works completed as the following work types and under the following conditions:

Culvert installation, maintenance or removal on a road or trail stream crossing (Subsection 44(1)(a)) is permitted providing that

1. equipment used for site preparation, construction, maintenance or removal of the culvert is situated in a dry stream channel or operated from the top of the bank,
    
2. in fish bearing waters, the culvert allows fish in the stream to pass up or down stream under all flow conditions,
    
3. the culvert inlet and outlet incorporate measures to protect the structure and the stream channel against erosion and scour,
    
4. if debris cannot safely pass, provision is made to prevent the entrance of debris into the culvert,
    
5. the installation, maintenance or removal does not destabilize the stream channel,
    
6. the culvert and its approach roads do not produce a backwater effect or increase the head of the stream,
    
7. the culvert capacity is equivalent to the hydraulic capacity of the stream channel or is capable of passing the 1 in 200 year maximum daily flow without the water level at the culvert inlet exceeding the top of the culvert,
    
8. the culvert has a minimum equivalent diameter of 600 mm,
    
9. a culvert having an equivalent diameter of 2 metres or greater, or having a design capacity to pass a flow of more than 6 cubic metres a second, is designed by a professional engineer and constructed in conformance with that design,
    
10. the culvert is installed in a manner which will permit the removal of obstacles and debris within the culvert and at the culvert ends,
     
11. the stream channel, located outside the cleared width, is not altered,
     
12. embankment fill materials do not and will not encroach on culvert inlets and outlets,
     
13. the culvert has a depth of fill cover which is at least 300 mm or as required by the culvert manufacturer's specifications,
     
14. the maximum fill heights above the top of the culvert do not exceed 2 m, and
     
15. the culvert material meets the standards of the Canadian Standards Association;

Clear-span bridge construction, maintenance or removal (Subsection 44(1)(b)) is permitted providing that

1. the bridge and its approach roads do not produce a back water effect or increase the head in the stream,
    
2. the equipment used for construction, including site preparation, maintenance or removal of the bridge, is situated in a dry stream channel or is operated from the top of the bank,
    
3. the hydraulic capacity of the bridge is equivalent to the hydraulic capacity of the stream channel, or is capable of passing the 1 in 200 year maximum daily flow, and the height of the underside of the bridge is also adequate to provide free passage of flood debris and ice flows, and
    
4. (iv) the bridge material meets the standards of the Canadian Standards Association, as applicable;

Pipeline crossing construction or maintenance (Subsection 44(1)(c)) is permitted providing that

1. the pipeline and associated works are installed in a dry stream channel at a depth so that the top of the pipe is at least 1 metre below the lowest elevation of the bed of the stream, and
    
2. in the case of an aerial crossing, the crossing is constructed in accordance with the requirements prescribed in paragraph (b) for clear span bridges;

Ice bridge, winter ford or snowfill construction or maintenance (Subsection 44(1)(n)) is permitted providing that

1. the materials used are removed from the stream channel before ice breakup and that only clean ice and snow are used, and
    
2. in the case of ice bridges, any logs, timber and other structural materials used can be removed in a safe manner;

Temporary ford construction (Subsection 44(1)(w)) is permitted providing that

1. the construction occurs at a time in the year during which the construction can occur without causing harm to fish, wildlife or habitat,
    
2. the 1 in 10 year maximum daily flow over the ford is accommodated without the loss of the ford and without scouring the stream,
    
3. a stream culvert, if used, is designed and installed to pass the average low flow during the period of use,
    
4. the channel is protected against any anticipated erosion
    
   1. during the period of construction and use of the ford, and
       
   2. after the ford crossing is removed,
       
5. sediment from approach ditches does not enter the stream,
    
6. the driveable running surface is erosion-free,
    
7. the stream remains in its channel and cannot be diverted down the road,
    
8. the ford will pass channel debris, and
    
9. the ford is removed at the end of the period of use at a time, before the next freshet, when the removal can proceed without causing harm to fish, wildlife or habitat;

Temporary diversion construction around or through a work site (Subsection 44(1)(x)) is permitted providing that the worksite is no larger than the minimum area required, and

1. if pumps, pipes or conduits are used to divert water around or through the worksite,
    
   1. the pumps, pipes or conduits are sized to divert the 1 in 10 year maximum daily flow for the period of construction, and
       
   2. any pump or intake withdrawing water from fish bearing waters is screened in accordance with the Fish Screening Directive of the Department of Fisheries and Oceans (Canada),
       
2. if cofferdams are used to isolate successive parts of the construction at the worksite,
    
   1. the cofferdams are designed by a professional engineer and constructed in accordance with that design, and
       
   2. the natural channel remaining outside of the cofferdams is adequate to pass the 1 in 10 year maximum daily flow during the period of construction, or
       
3. if ditches are used to divert flow around the worksite,
    
   1. the flow of water diverted remains within the stream channel,
       
   2. the ditches are designed and constructed to divert the 1 in 10 year maximum daily flow around or through the worksite and are protected from any anticipated erosion during the period of construction and use of the ditch, and
       
   3. the ditches are completely backfilled and the area returned as closely as possible to the natural state on completion of the works.

Best Practices

The best practices given here should be followed to ensure your proposed works will comply with Provincial standards. They are designed to help you protect species, habitats, water quality and quantity through the way you plan and carry out your works.

Planning and Design Best Practices:

Crossings should be designed by an appropriately qualified professional(s), and constructed in accordance with that design. To ensure impacts to fish and wildlife habitats and populations are minimized, stream crossings should:

• Be avoided on floodplains, meander bends, braided streams, or alluvial fans or any other areas where bank stability may be a concern;
• Avoid critical fish and/or wildlife habitat areas;
• Avoid disturbance to the bed and banks of the stream by using structures that will remain outside the bankfull width of the stream;
• Be aligned perpendicular to stream-flow;
• Minimize the width of the right-of-way clearing to limit impacts to onsite and adjacent riparian areas; and
• Use trench-less technologies (i.e., directional drilling outside the channel and floodplain and below the streambed) for pipelines and other utilities crossings.
• Incorporate opportunities to enhance the surrounding environment or to reduce the impact of the existing structure during replacement activities

For further information on the design of stream crossing structures, you should consult the following resources:

• Access Near Aquatic Areas: A guide to sensitive planning, design, and management
  http://www.stewardshipcentre.org/code/pdf/access2.pdf
   
• Forest Practices Code Fish Stream Crossing Guidebook
  http://www.for.gov.bc.ca/tasb/legsregs
  /fpc/FPCGUIDE/FishStreamCrossing/FSCGdBk.pdf

Operational Best Practices:

All individuals carrying out instream works should be made aware of and trained in the listed best practices. To comply with the Water Act Regulation’s Protection of Habitat (Section 42(1)) and Protection of Water Quality (Section 41) standards, you should follow these best practices:

Monitoring

• Construction activities should be monitored full-time during start-up and any instream works or sensitive activity, otherwise on a daily basis to the completion of the project. The environmental monitor(s) must be an appropriately qualified professional(s) and will be provided with written authority to modify and/or halt any construction activity if deemed necessary for the protection of fish and wildlife populations or their habitats. A sign should be posted listing the monitor’s company name and phone number at the entrance to or immediate vicinity of the job site.
• Forward a copy of this document listing standards and best practices for your works, and all appropriate plans, drawings and documents to the contractor/crew supervisor and keep it readily available at all times at the site while the work is proceeding.
• Hold a pre-construction meeting between the environmental monitor and the contractor undertaking the work on the site to ensure an understanding of the mitigative best practices for the project.
• Within 60 days of completion of this project the environmental monitor will complete and submit a minimum of one (1) copy of a monitoring report consistent with the recommended standard format to his/her client;

For more information see Appendix I: Monitoring.

Timing of Works (Subsection 42(1)(a))

• If works are scheduled for fish-bearing streams or if fish presence in the watercourse in not known, complete in-channel or bank work during the instream reduced risk work window approved for your region. To find out what the timing window requirements are for your area, contact your regional MOE office.
• Be advised that for certain fish and amphibian species at risk, there may be no window of least risk. Please contact your local WLAP office for more information.
• Only clear vegetation for worksite access and stream crossing right-of-way within the vegetation clearing timing window.
• Only undertake works during favourable weather and low water conditions.
• Complete the works as quickly as possible once started

For more information see Appendix II: Timing of Works.

Deleterious Substance Control/Spill Management (Subsections 41(a)(b) & 42(1)(d))

• Prevent the release of silt, sediment or sediment-laden water, raw concrete or concrete leachate, or any other deleterious substances into any ditch, watercourse, ravine or storm sewer system. The recommendations for sediment and erosion control outlined in the Land Development Guidelines for the Protection of Aquatic Habitat (Chilibeck et al, 1992) can also be used for reference.
• Ensure equipment and machinery is in good operating condition (power washed), free of leaks or excess oil and grease. No equipment refueling or servicing should be undertaken within thirty (30.0) metres of any watercourse or surface water drainage
• Ensure all hydraulic machinery to be used instream uses environmentally sensitive hydraulic fluids which are non-toxic to aquatic life, and which are readily or inherently bio-degradable
• Keep a spill containment kit readily accessible on-site in the event of a release of a deleterious substance to the environment. Train on-site staff in its use. Immediately report any spill of a substance toxic to aquatic life of reportable quantities to the Provincial Emergency Program 24 hour phone line at 1-800-663-3456
• Do not use treated wood products in any construction below the high water mark of the stream channel to prevent the release of preservatives toxic to fish.

For more information see Appendix III: Deleterious Substance Control/Spill Management.

Concrete Works (Subsections 41(e) & 42(d))

• As concrete leachate is alkaline and highly toxic to fish and other aquatic life, ensure that all works involving the use of concrete, cement, mortars, and other Portland cement or lime-containing construction materials (concrete) will not deposit, directly or indirectly, sediments, debris, concrete, concrete fines, wash or contact water into or about any watercourse. Concrete materials cast in place must remain inside formed structures.
• A CO₂ tank with regulator, hose and gas diffuser must be readily available during concrete work to neutralize pH levels should a spill occur. Train staff in its use.
• Provide containment facilities for the wash-down water from concrete delivery trucks, concrete pumping equipment, and other tools and equipment.
• Report immediately any spills of sediments, debris, concrete fines, wash or contact water to 1-800-663-3456. Implement emergency mitigation and clean-up measures, like use of CO₂ and removal of the material immediately.
• Completely isolate all concrete work from any water within or entering into any watercourse or stormwater system.
• Monitor the pH frequently in the watercourse immediately downstream of the isolated worksite until completion of the works. Emergency measures will be implemented if downstream pH has changed more than 1.0 pH unit, measured to an accuracy of +/- 0.2 pH units from the background level, or is recorded to be below 6.0 or above 9.0 pH units.
• Prevent any water that contacts uncured or partly cured concrete during activities like exposed aggregate wash-off, wet curing, or equipment washing from directly or indirectly entering any watercourse or stormwater system.
• Isolate and hold any water that contacts uncured or partly cured concrete until the pH is between 6.5 and 8.0 pH units, and the turbidity is less than 25 nephelometric turbidity units (NTU), measured to an accuracy of +/- 2 NTU;

For more information see Appendix IV: Concrete Works.

Isolation of the Work Area (Subsections 42(b) & 44(x))

• Isolate your work area from all flowing water, but do not cut off flow to downstream portions of the stream at any time during construction.
• Temporarily divert, enclose or pump the water around the work site. Ensure the point of discharge to the creek is located immediately downstream of the work site to minimize disturbance to downstream populations and habitats;

For more information see Appendix V: Isolation of the Work Area.

Salvage of Fish and/or Wildlife (Subsection 42(1)(e)

• Complete a fish and amphibian salvage for works prior to the start of works if any portion of the wetted channel will be isolated and/or dewatered. An appropriately qualified professional(s) must complete the salvage. It is the responsibility of the salvage crew to obtain the necessary permits required by the British Columbia Fisheries Regulations or Canada Fisheries Act prior to conducting the salvage activities;

For more information see Appendix VI: Salvage of Fish and/or Wildlife.

Sediment Control (Subsections 41(a)(b)(c) & 42 (1)(c)(d)(f))

• Ensure material, such as rock, riprap, or other materials placed on the banks or within the active channel or floodplain of the watercourse, is inert and free of silt, overburden, debris or other substances deleterious to aquatic life.
• Ensure machinery works from the bank of the stream and not in the stream channel to minimize impacts and to better enable mitigation of sedimentation.
• Minimize the disturbance to existing vegetation on and adjacent to the stream banks.
• Place sediment control measures before starting any works that may result in sediment mobilization.
• Construct any ditches, water bars or water diversions within the work area so they do not directly discharge sediment-laden surface flows to the stream. Divert such flows to a vegetated area where flows can slowly infiltrate.
• Remove excavated material and debris from the site or place it in a stable area above the high water mark or active floodplain of the stream, as far as possible from the channel.
• Protect this material from erosion and reintroduction to the watercourse by using mitigating measures including, but not limited to covering the material with erosion blankets or seeding/planting with native vegetation.
• When material is moved off-site, dispose of it in such a manner as to prevent its entry into any watercourse, floodplain, ravine, or storm sewer system;

For information see Appendix VII: Sediment Control.

Vegetation Management (Subsections 41(c) & 42 (f)(g))

• Limit vegetation clearing for access and at your work area.
• Consider other options when contemplating the need to remove vegetation. It is very often not the best choice for fish and wildlife habitat and species.
• Wildlife trees are important for many wildlife, bird, and amphibian species. You should avoid vegetation activities that will impact trees used for nesting or roosting. Section 34(b) of the Wildlife Act prohibits the your interference with bird nests, young, or eggs. This means that a wildlife tree containing an active nest, or a nest of species listed under the Act (i.e., raptors or species at risk), even outside of the breeding season, may not be felled.
• If you are proposing to top or remove trees, have the trees within the riparian area assessed by an appropriately qualified profession who is also a Wildlife Danger Tree Assessor to determine the presence and nature of the hazard.
• Where the danger can be removed by topping or removal of the dead limb this should be undertaken in preference to removal of the entire tree.
• Where the entire tree must be removed then the tree replacement criteria should be applied.
• Also in consideration of the importance of large woody debris to the stream/fish habitat and the importance of large diameter trees to wildlife populations, the stub of the trees should be retained where it is deemed safe to do so.
• Fall or top all trees so that the branches do not enter the stream channel. If any branches do inadvertently end up in the channel they should be removed offsite to where they will not enter the channel during high flows. Removal of limbs from the channel must be completed in a manner that will not disturb aquatic organisms.
• Fall the tree across the stream when falling across the stream cannot be avoided because of safety reasons (faller safety, buildings etc) and all methods of tree removal have been considered but cannot be safely employed. Removal of the felled tree must be completed in a manner that does not damage the banks and the bed of the stream. If possible, leave and anchor the trunk as large woody debris to be left within the riparian zone.
• Fall the tree away from the channel unless there is an immediate threat to life and limb and remove the material within the instream work window.
• Equipment used for vegetation removal should comply with this document’s listed best practices for deleterious substance control.
• Danger trees/limbs prior to the instream window to allow works to be scheduled within the timing window;

For more information see Appendix VIII: Vegetation Management.

Restoration of the Site (Subsections 41(a)(c) & 42(1)(c)(f)(g))

• Grade disturbed areas to a stable angle of repose upon completion of the work. These areas should also be revegetated to prevent surface erosion and subsequent siltation of the watercourse.
• Protect disturbed soil areas on the banks and areas adjacent to the stream from surface erosion by hydroseeding with a heavy mulch, tackifier, seed mix; by installing erosion blankets; and/or by heavily revegetating;
• Plant native trees, shrubs, and herbaceous plants that are appropriate to the site conditions to revegetate and replace impacted riparian vegetation.
• Restore all in-channel or active floodplain habitats that have been disturbed during the completion of works to a condition that is enhanced from their original state. The restoration will be consistent with a no-net-loss of fish and wildlife habitat.
• Remove any remaining sediment and erosion control measures (i.e., silt fence). Ensure all equipment, supplies, and non-biodegradable materials have been removed from the site.
• Complete post-construction multiyear monitoring to ensure your revegetation meets full survival.

For more information see Appendix IX: Restoration of the Site.

Standards and Best Practices | Stream Channel Maintenance

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