Why was the hydraulic mining ban lifted in 1893?

Why did they lift the ban of hydraulic mining in 1893? It was clearly bad for the earth, as it caused erosion and devastation to farm land. I don't see any sense in lifting the ban if they had legally banned that form of mining, and the earth was safe from it. I know that technology, culture, and society has changed since then, but I was looking at a history lesson and found myself curious as to why they lifted the ban at all.