Probably stating the obvious here but your going to continue to have this problem until you install some drainage that directs all that water from the downspouts and any residual surface water, to the street (pop up drainage emitter near the sidewalk).

Then you would need to look at the pure cash flow play of what type of rents can you get and is your cash flow return adequate to make the deal worthwhile, even if the residual value isn't there in the short term.

Many areas outside the city are much more affordable and offer higher cash flow while taking advantage of the residual appreciation from the major metro. 

of bottles/cans with stale beer residue/stench, which of course attracted 1000's of roaches that were in/on everything in the place.

Anything residual should be used to pay down the HELOC.

Water is now so hot they must be having a steam bath inside the bathroom & I found that the chrome coated shower rod started to rust from so much residual water vapor.

We look at the longer term 5 years and beyond in our UW to make sure the deal will cover expenses in year 1 and create residuals after that. 

My tenant cleaned all the water up but it’s unclear any residual damage in the wall or under the floor etc.

Google then tweaked the algorithm to catch people that did that.Then people did PNB, buying up expired domain names with residual domain authority, hundreds of them, put some thin content on there and link to the money-making website... and that worked... for a while, and yup Google tweaked the algorithm again and boom back to square one.That is what an algorithm update is and THAT keeps changing.. 

Residual Estimation Approach5.