Materials
* Culverts: any commercial conduit that is suitable for the required traffic loading.
* Rock: minimum 150mm nominal rock size.
* Aggregate: 50-75mm clean aggregate.
* Geotextile fabric: heavy-duty, needle-punched, non-woven filter cloth (minimum 'bidim' A34 or equivalent).

Installation
1. Prior to commencing any works, obtain all necessary approvals and permits required to construct the temporary watercourse crossing, including permits for the disturbance of bank vegetation, aquatic vegetation (e.g. mangroves) and any temporary instream flow diversion barriers or sediment control measures.
2. Refer to approved plans for location and construction details. If there are questions or problems with the location or method of installation, contact the engineer or responsible on-site officer for assistance.
3. Ensure that the location of the crossing will not interfere with future construction works.
4. Prior to significant land clearing or construction of the approach ramps, establish all necessary sediment control measures and flow diversion works (instream and off-stream as required), clearing only those areas necessary for installation of these measures.
5. To the maximum degree practicable, construction activities and equipment must not operate within open flowing waters.
6. Maintain clearing and excavation of the watercourse bed and banks to a minimum. Initially clear only the area necessary to allow access for construction. Clear the remainder of the approach ramps only when adequate drainage and sediment controls are in place.
7. If flow diversion systems cannot be installed, then conduct bank excavations by pulling the soil away from the channel.
8. Where practicable, construct the watercourse crossing perpendicular to the channel.
9. Where practicable, the approach ramps should be straight for at least 10m and should be aligned with the crossing.
10. Where practicable, direct stormwater runoff from the approach ramps into stable drains, adjacent vegetation, or appropriate sediment traps to minimise the release of sediment into the watercourse.
11. Shape the channel, if necessary, to receive the pipe/s.
12. If highly erosive soils are detected, then appropriately stabilise such soils as soon as practicable.
13. Cover the crossing footing with heavy-duty filter cloth.
14. Cover the filter cloth with a minimum 150mm of clean, 50 to 75mm aggregate.
15. Place the specified size and number of culvert cells and align them with the direction of the downstream channel.
16. Ensure the pipes extend at least 300mm beyond the proposed extend of rock fill.
17. Fill between the pipe/s with 75 to 100mm aggregate.
18. Cover pipe/s with sufficient rock (minimum 300mm layer) to satisfy manufacturer's loading requirements to avoid damage to the pipe/s resulting from the expected traffic load. Slope of rock face upstream and downstream of the culvert no steeper than 3:1 (H:V).
19. Form the shape of the road surface in accordance with the plans and/or standard drawings.
20. Apply a suitable cover of aggregate over the rock fill to form the trafficable road surface.
21. Finish construction and stabilisation of the approach roads including the approach ramps each side of the bridge crossing.
22. Take all reasonable measures to prevent excess rock, debris and construction material from entering the watercourse, especially any still or flowing water.
23. If it is not practicable to stabilise the access ramps against erosion, then install flow diversion banks across the width of each access ramp adjacent the top of the channel bank, and at regular intervals down the ramps (as required) to prevent or minimise sediment-laden runoff flowing directly into the watercourse.
24. Appropriately stabilise any disturbed watercourse banks.
25. Stabilise all disturbed areas that are likely to be subjected to flowing water, including bypass and overflow areas, with rock or other suitable materials.

Maintenance
1. Temporary watercourse crossings should be inspected weekly and after any significant change in stream flow.
2. Debris trapped on or upstream of the crossing should be removed.
3. Repair any damage caused by construction traffic. If traffic has exposed bare soil, stabilised as appropriate. Maintain a minimum 200mm cover over the culverts.
4. Check for erosion of the formed embankment, channel scour, or rock displacement. Make all necessary repairs immediately.
5. Check the bypass floodway making sure the banks are stable.
6. Check for excessive erosion on the approach roads.
7. Check the conditions of any flow diversion channels/banks and the operating conditions of associated sediment traps.

Removal
1. Temporary watercourse crossings should be removed as soon as possible after alternative access is achieved or the culvert is no longer needed.
2. Remove all specified materials and dispose of in a suitable manner that will not cause an erosion or pollution hazard.
3. Restore the watercourse channel to its original cross-section, and smooth and appropriately stabilise and revegetate all disturbed areas.