Couple of quick notes.
Water filtered underground helps replenish aquifers. Where everyone on a well gets thier water. Also the drainage of aquifers can cause a subsidence in the ground. Although not magic, the water is generally much cleaner than what is sent through the pipes by the govment. As for banning water collection, well like most laws, it is a worthless slug of a government employee trying to justify thier existence and salary,(paid for by those of us who are allowed keep what is left over of our earnings once the government gets it's graft off the top), by coming up with a new way for the government to get more cash via fines. To make noticable dent, the water collection would have to be on a gigantic scale.
As for water disappearing in areas where population is increasing, such as the drought in California. Check the historical record. It's a desert! It has droughts! Including those that have lasted hundreds of years. We have droughts, some quite severe in Geogia, some lasting years. The Atlanta metro area has over 5 million people and one major river with a rather small catch basin to replenish the water. The sad state is the hubris of the population.
As for carbon. A coworker and her husband make soaps to sell at local fairs. I give her mine, it's great for exfoliating the skin, and black soap is just cool.