Sixty-Seven million Baby Boomers have now started to enter their retirement years. One of their biggest challenges is making a retirement portfolio last during retirement. This is a challenge because of the fluctuating nature of future stock market returns. Hoover Dam designers faced a similar issue. They want to maximize flow from the dam while keeping the reservoir full. The amount of river flow replenishing the reservoir is dependent on fluctuating levels of annual snowfall in the mountains. This short story compares Hoover Dam's design to the retirement portfolio income problem. After reading this short story, you will gain a new appreciation for your own retirement income solution.