Those water collection barrels are not just popular in Portland, but strongly encouraged in city code and by the water department which is one of the most powerful government agencies in the state because they also control the hydroelectric stuff.
The county where this took place is one of the areas which is outside their jurisdiction.
I have a feeling this is going to be another case which leads to a conflict which will have to be tried and dismissed in Portland.
A lot of people think that because Portland is "Liberal", they are going to be anti-homesteader, and in this case, it was picking on a marijuana farm, which makes it a trigger issue for Portland politics. You start telling the hipsters who have half million dollar homes around inner Hawthorne that they can have rain barrels and front yard fruit and vegetable gardens, it won't be pretty. It would probably go over about as well as door to door gun confiscation in Grant's Pass.