where to put the water tower. it will need to be higher than the highest customer. explain that the higher the tower is placed, the more water pressure can be generated and thus their customer cups can be filled faster, but it will also take more energy to pump the water into the tower. once a group places its tower, it cannot be moved. explain the second goal of being the most efficient. whichever group can supply its customers and have the most water left over in the water tower wins the efficiency award.
once you say “start,” students have to work together to decide where to put the water tower. 