Water System Analysis for Peterborough, NH

D&A recently completed a computerized model of the Town of Peterborough, NH water system. The computer model was developed from base information, including GIS water main data. Hydrant flow tests were conducted with the assistance of Peterborough Water Department personnel to obtain pressure and flow information necessary to calibrate the model to actual conditions.

The calibration process involves adjusting pipe roughness coefficients and other water system parameters until the simulated results match recorded data to within a margin of less than 10%. After the computer water model was calibrated, it was used as a tool by D&A engineers to evaluate potential improvements to the distribution and transmission systems.

The development of the Peterborough water system computer model was key to the success of this project. Because the water model was calibrated to existing conditions, it could be relied on to simulate future scenarios. The model allowed engineers to quickly compare numerous potential improvements to determine the most economical projects to increase hydraulic capacity.

A list of potential capital improvements was developed which included water main replacement, cleaning and lining and new construction projects. These projects are recommended to increase fire flow protection, strengthen the transmission system and replace undersized or poorly constructed water mains. Peterborough officials are currently reviewing the recommended improvements to develop a plan for implementing an overall water system upgrade over the next several years.