Building Scenarios of Adaptive Capacity: A Case Study of Community Water Systems in Central Pennsylvania

Open Access
Whitehead, Jessica Chenault
Graduate Program:
Doctor of Philosophy
Document Type:
Date of Defense:
May 06, 2009
Committee Members:
  • Brenton Yarnal, Dissertation Advisor
  • Brenton Yarnal, Committee Chair
  • C Gregory Knight, Committee Member
  • Robert George Crane, Committee Member
  • James Samuel Shortle, Committee Member
  • mediated modeling
  • drinking water management
  • adaptive capacity
  • community water systems
  • climate change
  • system dynamics
Approximately 83 percent of the estimated 52,000 community water systems (CWS) in the United States serve fewer than 3,300 people. In the Commonwealth of Pennsylvania, about 945,000 people receive their drinking water from smaller CWS, and the CWS of Centre County provide an excellent example of small, rural systems with low human capital, changing regulatory demands, and aging infrastructure. With resources already stretched, it may be difficult for CWS managers to adapt to the impacts of future climate change. The purpose of this dissertation is to study Centre County CWS managers’ perceptions of their systems’ capacities to adapt to more frequent floods and droughts. Results from nine interviews with Centre County CWS managers and from managers’ social network maps revealed that these managers are limited in their availability to raise funds, comply with water quality regulations, and upgrade system technology. Some managers of small, rural systems compensate for scarce human capital and financial resources by taking advantage of layered social and institutional capital. One of these systems is the Gregg Township Water Authority (GTWA). In a series of mediated modeling focus groups, GTWA members and stakeholders helped to build a scenario generator that allows CWS managers to explore their potential adaptive capacities. The system dynamics-based Community Water System - Future Adaptive Capacity Scenario (CWS-FACS) generator allows managers to explore how system management variables change under five climate scenarios and three growth rate scenarios. The sample scenarios presented to the GTWA suggested that the system’s financial adaptive capacity is low and the stress on the system from a lack of financial resources may be greater than the climate-related stress. Despite this result, managers remained concerned about climate change and found the scenario results to be plausible and consistent. They also valued the model’s flexibility and its utility as a learning tool for climate and other influences affecting their system’s management. Ultimately, these results indicate that mediated modeling and system dynamics are effective approaches for making climate information relevant to resource managers. The methodology can be transferred to other sectors and regions, making it useful for climate extension and outreach programming.