one thing to know about gourds (squash/cucumbers/melons) is they suck the nitrogen all out of the soil so you can't plant them in the same place year after year. you have to plan to move them and rotate with nitrogen fixing plants like legumes and clover.

i'd look into permaculture if you want to do the stream thing. the biggest thing is going to be keeping the pool from being stagnant and developing algae so you probably need a pump to circulate the water.