Upwards of 80% of the capital cost of water and wastewater infrastructure is tied up in pipe networks; similarly a significant proportion of operating cost derives from the operation and control of networks. Even so, many water utilities still only have a rudimentary understanding of how their networks really behave. Gathering operations, planning and maintenance data along with GIS information system attributes and other data into one single tool, a model that simulates or parallels as close as possible the behaviour of actual operating conditions of the networks, can allow asset managers to make the right decisions at the right time. The advent of cheaper and more precise system sensors and monitors will allow even more focused operation and even prediction of events to help ensure the necessary supply resilience and optimized costs.

Hydraulic and hydrological modelling are essential tools for investigating how networks operate, for planning and designing improvements to water infrastructure systems and for predicting water cycle processes. Well-constructed and calibrated hydraulic and hydrological models can clearly demonstrate the consequences of fluctuating and increased water demands, pipe flows and pressures in water and wastewater systems, the impact of climate change on the distribution and quality of water resources, above and below land surfaces, and on infrastructure by forecasting water pressures and flows, deficiencies and risks, and lay bare the effectiveness of proposed solutions. Both hydraulic and hydrological analyses create opportunities for improved operational performance and cost savings.

Network and Pipeline Hydraulics

WSP services encompass pressurized piping and networks, and gravity-flow piping. Our specialists have investigated pipeline breaks and re-engineered systems conveying water, sewage, acid/caustic, slurries, sand paste, hydrocarbons and steam. We have also investigated and resolved odour and/or surcharge in combined sewers, drop shafts and tunnel/outfall systems to reduce basement and surface flooding. Services range from raw water transmission lines and risk evaluation and valve criticality to pump, valve and piping design and testing, through to dynamic models of hydraulic grade lines.

WSP provides advanced studies and designs for hydraulic structures including storm inlets, drop shafts, combined sewer overflow (CSO) tunnels and outfall structures for storm, sanitary/combined, or industrial or mining systems. Our services encompass storm water, industrial and mining systems, wastewater and CSO, and review and training.

Plant and Pump Station Hydraulics

WSP provides advanced hydraulic solutions for process and flow control challenges in plant and pumping systems for the water, wastewater, mining, hydropower and industrial sectors around the world. We offer a full range of services from conceptual studies to detailed design, commissioning or performance monitoring for process piping in plants and pump stations and for pipelines conveying water, sewage, acids or slurries. We also specialize in fluid transients (water hammer) and 3D numerical or scale models.

For example, for South West Water (SWW), a provider of water and sewerage services in Cornwall and Devon, UK, WSP built a water distribution network model for the Pynes distribution zone serving Exeter and parts of the surrounding area, to simulate flows and pressures throughout the zone and calibrated it against field test data. We subsequently converted it to a dynamic model, with visualization of the model output, which could run online to show conditions in the network on a minute-to-minute basis and identify anomalies that indicated incidents requiring operational response interventions. We used the model to confirm the required network changes enabling the outage of a service reservoir, allowing SWW operation teams to have increased confidence that there would be no detriment to customers. 

Water systems require a high degree of reliability to maintain operation. At WSP, we use the most advanced modelling tools available for piped systems to accurately predict performance under normal, peak and emergency conditions, reducing capital and life cycle costs. We also use in-house sensors to check real-world performance, optimize energy use and monitor processes.

Tekniska Verken, the municipal utility in Linköping, Sweden, is investing heavily to increase capacity and reliability of its water supply, and to further improve purification while minimizing the risk of parasites, bacteria and viruses entering the drinking water supply. Tekniska Verken commissioned WSP to build an AQUIS computer model for its entire water supply network. During the project, it was decided that the model should be supplemented with a number of online pressure sensors, feeding into a live real-time model. The driver behind the project was a wish to get control over a very complicated network. The model was used early on to establish pressure zones across the network adapted to operational conditions. Another key driver was the need prepare for emergencies by investigating and mitigating key failure scenarios, before they can occur. The real-time model is currently operational and in frequent use by both planning and maintenance teams. Together with WSP the municipality has created an ambitious development scheme, including the installation of a further 100 online pressure sensors. The sensors are connected via fiber to a SCADA surveillance system, which in turn automatically feeds the AQUIS model. The model is seen as a success story and is currently being used as a best practice example for future development throughout Sweden.

WSP’s water resources and hydraulic specialists are experienced with a variety of flood control and conveyance facilities including levees, coastal defences, dams, canals, pump stations, detention basins and impoundments, and intake, flow diversion and outlet structures. We utilize our in-depth hydrologic and hydraulic engineering knowledge and apply our extensive experience to assist municipalities in safeguarding their communities and preventing loss of life and property.

River Modelling and Engineering

WSP has worked on the implementation of large-scale, wide-area water system and river management schemes, and our experience includes hydrologic and hydraulic solutions to address the engineering challenges associated with transportation and environmental restoration projects. Specialized technical services include waterway modelling, highway drainage and hydraulic design, bridge hydraulics and scour analysis, scour protection, and floodplain analysis and flood control design. We have also contributed to stream restoration and protection using fluvial geomorphology-based stream restoration and bioengineering techniques.

Throughout the regions, WSP employs various modeling software packages for modelling 1D and 2D flows in rivers and over flood plains. Integrated flood risk assessments are also made where surface water processes and flow in sewage networks are modelled simultaneously. HEC-RAS (US Army Corps of Engineers) is also used for 1D modelling in rivers and culverts. Services include:

• Laser scanning and terrain modelling

• Dam break and flood propagation modelling

• Flooding analysis

• Urban hydraulic modelling

• GIS and production of flood maps

• Analysis of production losses in hydropower rivers

• Erosion/deposition modelling in rivers

Coastal Engineering and Modelling

WSP works with ports and with coastal engineering (breakwaters, quays, locks etc.), from early feasibility studies to detailed design. As coastal modelling is also a growing field, we use software for modelling of 2D and 3D flows in estuaries and coastal areas. Applications include:

• Water exchange studies in estuaries and coastal areas

• Modelling of waves and currents in ports

• Modelling of wave impact on structures

• Pollutant transport and mixing in coastal waters