Source: https://www.quantsurv.com/sectors/energy/hydro-and-tidal
Content format: Markdown version of the public page.
Content reviewed: 2026-10-13

# Hydro and tidal

Quantity surveying and claims support for civil and installation packages on hydroelectric and tidal projects.

## Commercial challenges and how we approach them

Hydro and tidal construction combines water-retaining or water-channel structures with generation equipment, access and connections. Packages may include intakes, channels, powerhouses and associated civil works. The account needs to distinguish construction quantities from separately supplied equipment.

### Waterway excavation and ground assumptions

#### The Challenge

Hydropower tunnels, intakes and penstocks can encounter ground or groundwater conditions that change support, excavation and lining requirements. A quantity change and a change in excavation method have different commercial effects.

#### Our approach

We compare the contract's ground information with the geological records and the engineer's instructions. Extra excavated volume, a different support requirement and reduced advance are assessed separately: they need different evidence and may receive different treatment under the contract. That separation also helps avoid charging the same resource through a revised excavation rate and a delay claim.

### Keeping water controlled during construction

#### The Challenge

Diversions, cofferdams and pumping have a duration as well as a construction cost. A changed sequence can keep them in use beyond the period priced.

#### Our approach

We identify the priced water-management assumptions and the engineer's required sequence. Actual flow, access and plant records are used to assess additional temporary works and distinguish ordinary working conditions from compensable changes.

### Turbine equipment meeting civil structures

#### The Challenge

Turbines, gates and embedded components need to align with concrete and waterway construction. Late manufacturer information can change cast-in items, openings and installation access after the civil package is committed.

#### Our approach

We track revised vendor details through cast-in items, openings and installation access, checking both additional work and any superseded provision.

### Testing when suitable water conditions are unavailable

#### The Challenge

The plant may be finished when the required flow, head or tidal conditions are unavailable for its performance test. Repeating the test later can involve remobilising specialists; retaining them on site has a different cost. The contract's test conditions and attendance allowance therefore need to be understood before the commissioning period starts.

#### Our approach

We review the contractual test conditions, attendance and payment milestones with the technical team. Extended or repeated testing is assessed against the actual dependency and the records of resources retained.