Implementation strategies for water resources projects under uncertainties of completion time

Recent analyses of the water resources development in India over the last 40 years, reveal that proliferation of projects, project construction delays and non-realization of created irrigation potential, are major issues of concern. Water resources projects in other countries often experience delays in project completion. However, the development of project construction implementation strategies, that is, determining the appropriate start year for each individual project in a system, does not usually anticipate the impact of potential project completion delays. The primary purpose of this research was to evaluate the effect of uncertainties due to construction delays on water resources project implementation strategies. System analysis approaches involving simulation and optimization are used to develop project construction implementation strategies. In this research, simulation, dynamic programming optimization, and exhaustive search using simulation techniques were applied. Project completion time was treated as a random variable. Historic data on planned and actual construction times and associated construction costs were assembled from the US Bureau of Reclamation's Central Utah Project. Based upon this data, many realizations of project completion tinges (accounting for potential delay) were stochastically generated and the associated optimal implementation strategies were assessed using dynamic programming optimization and exhaustive search techniques. The results of the optimization models were statistically evaluated to determine the stability of the optimal value of the start year of construction for each project for various demand scenarios, budget scenarios, and cost escalation functions. The developed methodology is demonstrated by application to a hypothetical fire project case study, based upon data from the Bonneville Unit of the Central Utah Project. The variability in optimal construction start dates was studied for each project for possible selected combinations of project delays. The following aspects were also evaluated: cost increases due to construction delays; effects of inaccurate choice of start dates; effect of demand targets on project selection; effect of funding level on project selection: and the effect of a yearly minimum construction constraint on project selection. The results showed that out of the five projects tested, two projects were insensitive to delays and one project was exceptionally sensitive to delays in any of the projects in the system. The study also showed that an inaccurate choice for start times of projects in the system can result in substantial increases in the construction costs.