Leveraging Hydraulic Models
The preliminary design phase of a major water infrastructure project is a crucial step in capital project delivery. The Owner and designer need assurances that the project will operate as intended, in the most efficient manner possible. Calibrated hydraulic models offer an effective way to analyze system hydraulics and operations under a multitude of varying “what-if” scenarios. This paper focuses on the use of hydraulic models during the preliminary design phase of large pump station, storage, and pipeline projects. Several case studies will be presented showing how the use of a hydraulic model upfront can save money and headaches in the long run.
Utility A leveraged their investment in a calibrated H2OMAP Water extended period simulation (EPS) model to evaluate the impact and effectiveness of several elevated storage tank options including varying locations, volumes, and operational parameters. Modeled tank levels and pump station flows for each scenario were presented along with GIS mapping of system pressures and available fire flows to easily communicate the differences between the various alternatives. Hydraulic operations was a key factor in determining the recommended tank option.
Utility B initiated a new pump station project to diversify water supply by integrating aquifer storage and recovery (ASR) and brackish groundwater desalination resources to expanded service areas. As part of the preliminary design process, the calibrated EPS InfoWater model was used to develop system curves under multiple demand and operational scenarios to assist with pump selection. In addition, the InfoWater model was used to evaluate preliminary conceptual alternatives for integrating a large off-site groundwater supply. The hydraulic modeling was the basis for identifying and programming water distribution improvement projects to effectively integrate the new water supply and also served as the basis for preliminary design of these facilities.
Utility C initiated a groundwater supply project to diversify and expand water supply to a rapidly growing population. The InfoWater model was also used to evaluate the impact of the new groundwater supply on the distribution system. The system curve feature in InfoWater was utilized to develop system head versus flow curves under various operational conditions. The curves were then used to select the appropriate distribution pumps for the new well supply. The InfoWater model was also used to conduct water age analyses to characterize the potential impact of the new groundwater supply on water quality in the distribution system. A series of 28-day water age simulations were performed and the InfoWater model data was exported to GIS and a surface was created to visualize the relative water age throughout the system.
Hydraulic modeling was a key element in all of the preliminary design efforts described above. It allows the designer and Owner to evaluate a broad range of options at a relatively low cost. Using a calibrated hydraulic model also provides assurances that the assumptions used for the design process are based on sound engineering analysis, resulting in increased design efficiency and confidence during the start-up process. A small investment in hydraulic modeling at the initial stages of water distribution facility design can lead to huge monetary payoffs in terms of optimized facility sizing and efficient operations over the life cycle of the asset.
- Scott Cole, P.E., Freese and Nichols, Inc.
- Melissa Brunger, P.E., Freese and Nichols, Inc.
- Stephanie Neises, P.E., Freese and Nichols, Inc.