That's too high, most estimates are ~80-100 gallons per person per day, average houshold size is 2.6 so that puts you closer to 100,000 gallons per household per year. I also question how those estimates are so high, my family of 4 averages closer to 50 gallons per day at home based on our water bill and we don't do anything extreme, we take regular baths, wash our clothes by machine wash, run the dishwasher every other day on average, brush our teeth twice a day, etc. The only "conservation" effort we put into water is not watering our lawn, in fact I drilled out the restrictor in my shower head because I HATE low flow showers and I believe I've got an old school high GPF toilet since my house is from 1963 and most things have not been updated in it.