Reservoirs, sequenced as a programme
An illustrative model of a programme of large raw-water storage reservoirs, built over two decades by the same limited supply chain. It rebuilds a representative scheme from published planning documents, then asks what sets the pace of each scheme and how the programme should be sequenced.
What the model is for
When several large schemes draw on the same plant, people and specialist engineers, the order they are built in matters as much as how each one is built.
- Status
- Illustrative model
- Purpose
- Show what sets the pace of a reservoir programme and how sequencing changes it
- Sector
- Water: raw-water storage reservoirs
- Scope
- Construction of a representative scheme, and a programme of schemes built over two decades
The model shows how we use systems modelling on a public client's programme. It starts from the physical work, the earth that has to be dug, moved and placed, and builds up to the programme from there.
How we went about it
Why sequencing matters
New storage reservoirs are among the largest earthworks projects a country undertakes. A programme of them, built over two decades, draws on the same earthmoving fleets, operatives and qualified engineers.
Each scheme is usually planned and costed on its own. The questions a programme sponsor needs answered sit between them: which scheme sets the pace, when the programme peaks, where the shared constraints bite, and whether a different order would make the whole programme quicker, cheaper or less risky.
How the model is built
Each layer builds on the one below, so a change in the ground, the weather or the order of schemes flows through to the programme.
- The schemeA representative reservoir rebuilt from published documents: footprint, embankment, the clay dug from the basin and the fill it has to become.
- The seasonEarth can only be placed in the drier months, so the work is planned season by season against the weather record.
- The resourcesCrews, plant and staff by month, including the engineer's team the law requires on site during construction.
- The programmeSeveral schemes on one timeline, with plant and teams able to move from one scheme to the next.
- The leversWorking hours, land take, methods and technology, each tested for its effect on time and resources.
What the model shows
Four points from the illustrative model that a sponsor would want to know before committing to a sequence.
Planned independently
Each scheme starts as soon as it can. Peak: 5 at once.
Sequenced as a programme
Fleets and teams move from one scheme to the next. Peak: 3 at once.
The constraint that matters most is often shared: the small pool of engineers qualified to oversee new reservoir construction, and the earthworks capacity of the whole market, not any one contractor.
What the model does and does not claim
It is a planning model built from public information, and it is not a design, a programme of record or a cost estimate for any scheme.
- A representative scheme. Quantities and methods are rebuilt from published documents, and where a value is not published it is inferred and labelled as such.
- No costs shown. The model can carry a cost layer, but no rates are published here.
- Weather from the record. Working seasons use historical weather, so an unusual year can move the result.
- Programme timing is illustrative. The programme view tests sequencing; it does not forecast when any real scheme will be built.
Related solutions and services
Programme questions like this sit somewhere between modelling, advice and governance.
Talk to us about a programme of schemes
Tell us about the schemes you have to deliver and the resources they share. We can help set out what sets the pace and test a better sequence.
Start a conversation