If you want go to this route, then you might find the cost of your cereal going up. More than 98% [1] of the water usage attributed to beef/cattle (and other animals) is an indirect measurement - it's from the estimated water usage in the production of the feed that's given to them. Cattle themselves directly use next to no water. So you'd need to add your water tax to grains and other such products.

Another interesting datum is that the average head of cattle has a water footprint of 2056 (m^3/year), while it's 2842 [2] for the average American, and 1071 for the average Chinese. There are 94 million cattle in the US, and 332 million people.

[1] - https://waterfootprint.org/en/water-footprint/product-water-...

[2] - https://www.researchgate.net/publication/221830102_The_Water...