Construction - Water Pipes

Water Comprehensive Water System Strategic Plan

Providing quality water for today's needs is challenging. But ensuring that a water system can accommodate future demands can be daunting. It requires constant planning and periodically, extensive reviews of the system.

It had been thirteen years since PWD conducted a long-term infrastructure plan. The District has experienced steady growth during this period. In 2002, PWD undertook a comprehensive review of the water distribution system. The result - the Comprehensive Water System Strategic Plan (CWSSP). The review evaluated the water system to identify improvement recommendations that will guide investments over the next 20 years.

The overriding goal of the plan was to improve service and customer satisfaction. The strategic planning process looked to address a number of key questions including:

  • What would be the future demand required to serve the existing service area?
  • How well is the water system meeting service goals?
  • What improvements are required to meet the service goals?
  • What are the costs associated with the improvements?
  • How can PWD best operate its water system in the future?

Future Demand

To estimate future water demand, an analysis of population growth in the service area was undertaken. In addition to a review of census trends, a spatial analysis of the growth patterns was made to identify the percentage growth anticipated to occur within the current service area of the District. Meetings were held with served communities to share the results of the growth study and ensure that the overall evaluation would reflect the priorities of the municipalities. For the purposes of determining future demand requirements, the most conservative population estimate was used. This study projected an average 70 % increase in population in the seven suburban towns and an average of 31% for the three urban core communities over the twenty-year study period. The average day demand is anticipated to rise from 25 MGD in 2000 to approximately 31 MGD in 2020. The corresponding maximum day demand would increase from 38 MGD to 46 MGD.

System Status

A series of evaluations were made to assess the condition of the water system including: hydraulic sufficiency, system reliability, regulatory compliance and aesthetic quality of the water. It was determined that the water system was in good condition but would require substantial investments during the upcoming decades to maintain and improve water service and to address an aging infrastructure.

Capital Improvements

A computerized hydraulic model of the water distribution system was developed and used to analyze the current state of the system and to evaluate alternative improvements. A program of improvements was identified to address potential improvements in: pump stations, storage capacity, fire flows, service pressures, water main renewals and transmission system reliability. The primary short-term recommendations include consolidation of the two current pressure zones which service Windham and Gorham into a single pressure zone and increasing the rate of water main renewal and replacement by two to three miles per year.

Implementation Costs

The strategic plan identified approximately $92 million dollars in improvements to be undertaken over the 20-year study period. This amount would be in addition to the $94 million dollars the District would spend if the current rate of capital investments were continued through the period. A financial model was developed to evaluate the impact on rates of the proposed capital program. A more detailed evaluation of the first 10 years of the identified projects analyzed alternative rate increase strategies.

District Operations

An evaluation of the Operational Department of the District identified a number of strategies for optimization. These included outsourcing a larger percentage of capital and maintenance work, incorporating a higher level of technology in daily operations, an increase in training and a reassignment of resources. A general increase in planning and tracking was also identified as a method of improving operations.