Usage Up 50% : Water Abuse in Multi Family

[Shane Pearlman]

I have a duplex with 3brs / 2.5ba on each sides which we have owned for 7 years. The property is Master Metered for water. The tenants pay a fixed water fee, which I base on an average monthly amount over the past 12 month of usage, and then adjust for family size should there be a turnover. 

One on side, the family is on their 4th year and is quite stable. On the other, A new family moved in at the beginning of May. As you can see from the numbers below, water usage has gone a bit out of control in the last 6 months:

12/05/14   24,450 Gallons

10/06/14   20,950 Gallons

08/06/14   20,800 Gallons

06/30/14   16,400 Gallons

04/30/14   16,100 Gallons

We did a cohesive check for leaks in case that was an issue, but it does not appear to be one (according to the water dept). 

The other factor which complicates my math, our county has been facing the worst drought in recorded history. As such, we have all been asked to stop watering lawns etc.. which has substantially lowered the bill in summer compared to other years. It makes the base harder to extract from my historical patterns. In addition, water rates are going up rapidly, but it is not quite as clear yet where they will land this year.

Do I simply try to bill the monthly overage to the new tenant for the time being? Could work, but I don't feel it is totally fair given all the other price fluctuation factors.

Does anyone have a nice spreadsheet they use which takes into account the price tiers?

Has anyone experimented with some of the more affordable sub-metering systems successfully? I know see that they don't necessarily hold up in court when challenged. 

Any good tips on creating greater water use awareness in my tenants? It goes beyond the cost to me, I live here and want my community to pull together during this challenging period. I already put in low flow everything. =)

If sub-metering could work, that would be a great things to include in my 4plexes up north and pass the actual cost onto the tenant. Seattle has an evil scam going on, in which I am not allowed to bill my low income tenants (ahem students) more than $25 /pp a month for water, but since it is master metered and I don't qualify as low income, I have to eat the difference. It is A LOT of money.