12,374 yen water bill

I live in an apartment complex where water is shared between tenants. In the beginning, all was fine. About 28-40 at most for 2 months worth of water. The most expensive it has ever been is around 4800 yen.

My husband moved in and they said we would have to pay for two. So we were expecting around 6000-8000 at most. The bill was 12,374. I have never received a bill this expensive for water in all of my years in Tokyo, even when I lived in a house of 3-4 and we shared utilities.

I just want to know if this sounds normal at all? Or could there possibly be a leaking pipe or something going on somewhere? Right now that is the price between 4 tenants, 2 being my husband and myself. Granted, we weren't even around for about 2-3 weeks to even utilize the water that much, and being out of the house often, and doing laundry about once a week, we are not showering down waterfalls of H2O everyday lol. I agreed to split the bill, so I understand I cant complain about not being there but being charged, but I am just worried that I am having to pay for a broken pipe or some kind of water leakage problem they are having and not addressing.

Until I moved into this apartment, I was paying around 1100-2000 per month for water, through a normal water company for my individual unit.

Thanks for any input given.

P.S. between 4 tenants, the total water bill was 24,751. We are paying half of that. Nearly 25,000 yen water bill for 4 people?  Does that sound right? Has your water bill ever been almost as much as your electricity bill?