Task: Question Answering
Input (English): Process:  -A dam is built in an area prone to flooding -A large amount of rain occurs -The water builds up behind the dam -The dam opens its floodgates when it starts to get full -The water flows into a river below the dam -The dam closes its gates -The dam will occasionally open its gates again to gradually release more water -Eventually all of the floodwater will be slowly released into the river without causing any flood damage.
 Question: What is the effect of water needs to be used for hydroelectric power on stopping the flow of water to an area.?
Output (English): for