I don't think you understand the actual facts.
One cow requires over 100 liters of water per day. 1 liter of milk requires 990 liters of water to be produced. And that water doesn't just magically go back to where it came from; the water tables get severely depleted when tens of thousands of liters per day are withdrawn. The water that does make its way through the livestock and back to the water table is no longer pure (about 50% of all water pollution in the US is from the livestock sector). In addition the livestock sector causes 55% of soil erosion in the US. The massive amounts of land that are required to grow feed for livestock (notably, only 10% of the energy in the feed reaches humans) and land taken over to grow livestock represent a massive portion of ecosystem destruction and loss of biodiversity. Also, greenhouse gas emissions from livestock account for 18% of greenhouse gas emissions, more than transportation.
You might not feel obligated to stop eating meat, but you should be aware that supporting the livestock industry does adversely affect the environment. I personally love meat, I'm not going to stop eating it. However, I try to buy local and organic to reduce the negative impact.
(Data in this post taken from the United Nations' Food and Agriculture Organization's "Livestock's Long Shadow". H. Steinfeld,
P. Gerber,
T. Wassenaar,
V. Castel,
M. Rosales, C. de Haan
- 2006, 390 pp.)