Ive found its kind of counterproductive to try and get water sub-metered and very costly but i did find depending on where your at like Cleveland for instance there is a program where you can get a sort of smart reader attached to your existing meter that will give far more accurate readings than what the meter currently measures. im not really looking to modify much just make sure everything is as accurate and fair as possible.

My short-term goals are to get my feet wet with a SFR and possibly dipping into flips this year, and from there scale and modify my strategy.

Otherwise, if your lease doesn't break down the portion of the rent that each is responsible for you could simply modify the lease to be between You (landlord) and Nisha and Katie (tenants) and leave it to them to figure out where the money comes from.

@Pete Woelfel I'm sure you are already aware but since the no winter move out topic came up, I wanted to chime in quick.When you use a MTM lease with a no winter move-out clause, it's actually a modified term lease that will change how you the landlord can provide notice or ask the resident to move-out. 

HMLs will sometimes charge 1-2 points or a fixed amount.In Texas, there is a form filed in the real property records noting the new maturity date and any other modified terms. 

And you will need to make is clear that they have no right to modify a contract you have with a contractor.  

From a legal perspective, he's going to have a tough time collecting.If there's still time to modify the deal, perhaps you can get the price bumped up to cover the commission.

One of my favorite sayings from my dad (who got it from his dad), of course modified for current prices

Chances are they will close the HELOC and modify it into a 20 year loan.  

(Golden's great too, but pricier too.)Not sure how far down the rabbit hole you want to go, but you could also look for a place with some kind of separate basement for that first place and then do a modified house-hack to offset your mortgage while you're there.