How do I irrigate the dry patch in virtual villagers 2?

You need to build a dam. once you have tec 2 for building drag the builder over to where the dry patch is and they will start to build the dam once the dam is built crops will grow... soon birds will start eating your crops! drag an adpt farmer to the twisted wood .... next to the twisted vines at the top behind the research shack... 2 times and they will build a scarecrow and you will never have problems with the birds eating your food!