Our Services
Replace or Upgrade Water Mains
In these types of jobs, we have an existing water main that needs to be upgraded. The upgrade process can follow two different approaches:
- Remove the old main and install a new one in its place.
- Lay a new main while the existing one remains in the ground.
These jobs are typically carried out along live roads, which come with significant complexities. Productivity is much slower compared to jobs in open areas because we are dealing with traffic, existing underground services, limited working space, and strict council regulations. Special care must be taken to ensure that excavation, pipe laying, and reinstatement are planned properly to avoid unnecessary delays and unexpected costs.
Key Considerations for Estimating Costs
1. Understanding the Site Conditions & Existing Services
- The first step in estimating these jobs is to evaluate the site conditions carefully.
- There are usually multiple existing underground services running along the road—water mains, sewer lines, stormwater drains, gas pipes, electrical conduits, and telecom cables.
- We must allow for the cost of utility locating and NDD (Non-Destructive Digging) using a vacuum truck to confirm the exact location of these services before excavation begins.
- Dial Before You Dig (DBYD) plans must be obtained and reviewed to identify potential risks.
- A site walk along the pipe run is crucial to assess accessibility, working space, and any potential obstacles.
2. Selecting the Right Excavation Equipment & Understanding Productivity
- Because these jobs are done along a live road, space is limited, and using large excavators is often not an option.
- Choosing the right machine size is crucial—a small machine may be required, but this means the excavation process will be slower.
- If we have a scenario where a new pipe needs to be installed within 300mm of an existing main, the excavation must be done with extreme care to avoid damaging the live pipe.
- If we are laying a pipe in a narrow space between a footpath and a kerb (e.g., only 600mm clearance), the work will be significantly slower. This means productivity will be low, and we must account for additional time in the estimate.
3. Allowance for Traffic Control & Road Occupancy Costs
- Any pipework along a live road requires proper traffic control planning to ensure both worker and public safety.
- Traffic control costs can be significant, including:
- Setting up detours and lane closures.
- Providing traffic controllers on-site.
- Obtaining necessary council approvals and permits.
- Road occupancy fees must be included in the estimate, as councils and road authorities charge fees for occupying public roads during construction.
4. Spoil Management & Tipper Requirements
- During excavation, a large volume of spoil (excavated material) must be removed.
- If we are working along a live road, spoil cannot be stockpiled on-site and must be loaded directly into a tipper truck.
- The estimate must include allowances for tippers and disposal costs at an approved facility.
5. Trench Backfilling & Reinstatement Costs
- If the new water main is being installed within or close to the live road, we cannot simply reuse the excavated material for backfilling.
- In such cases, we must allow for the cost of importing select fill material to properly backfill the trench.
- If the excavation is near footpaths or driveways, there is a high chance that some sections of concrete, asphalt, or kerb will be damaged and will need reinstatement.
Key reinstatement costs to consider include:
- Concrete saw-cutting for driveways and footpaths.
- Concrete reinstatement for any damaged driveways.
- Temporary road plates if driveway access needs to be maintained during work.
- Grass verge restoration if excavation affects landscaped areas.
- Asphalt patching if road pavement is cut.
6. Site Constraints & Project Duration Considerations
- Working in a tight area along a live road means productivity will be slower than an open site.
- If the pipe run is long and excavation space is tight, the work will have to be staged, meaning longer project duration.
- The estimate should allow for additional time and resources based on the complexity of working conditions.
Why Accurate Cost Estimation Matters for Water Main Upgrades
Replacing or upgrading existing water mains is not as straightforward as laying a new main in an open trench. Live road conditions, existing services, limited excavation space, traffic management, spoil disposal, and reinstatement all add complexity and cost.
At WSE Sydney, we specialize in accurately estimating these factors, ensuring that all potential risks and costs are accounted for before the project begins. Our expertise ensures that contractors, developers, and civil companies have a clear financial picture of what is required.
📧 tenders@watersewerestimatingsydney.com.au
📞 +61 451 404 645
