75 Water drops
Under all the webs is a log system sitting on the river and that is how you will break some of the webs. As the crops rotate they will hopefully match up with webbed crops.
You need to free the spider and send him through the other two empty nests before he vacates the board.
Luckily you only need two types of crops so watch the crops on logs carefully and try to set them up so as the logs move they will rotate and make a row.
If you can move the sheep down it will help with the spider in the top nest but isn't necessary.
Guide the sheep to the hay and make as many matches on grass.