a consulting engineer has been engaged to advise a town how best to proceed with the construction of a 200000 water supply reservoir. since only 120000 of storage will be required for the next 25 years, an alternative to building the full capacity now is to build the reservoir in two stages. initially, the reservoir could be built with 120000 of capacity and then, 25 years hence, the additional 80000 of capacity could be added by increasing the height of the reservoir. estimated costs are as follows construction cost annual maintenance cost build in 2 stages first stage 120000 reservoir $14200000 $75000 second stage add 80000 of capacity $12600000 $25000 additional construction cost build in full capacity now 200000 reservoir $22400000 $100000 if the interest is computed at 4%, which construction plan is preffered ?