We are under contract for a 1700 sqft 3/2 home on just over an acre in spring branch, tx.

For just under $100 per year they will insure your water service and sewer lines.

Just this evening I got a call that a water line froze and broke.

Scottsdale and the East Valley are very popular for Airbnb's due to the constant influx of events such as golf tournaments, spring training, auto shows, and so on.

That would add $700 back into your monthly cash flow and turn it from a negative cash flowing property (-$257 per month, per your analysis), to about $450 per month in POSITIVE cash flow.Also, water & sewer and insurance estimates seem a bit low, but that could just be the area of this property as compared to my area. 

For example, you can get the tenants to mow the lawn - but most tenants will not drag hoses around to water the lawn.  

@Ryan Cotic insurance and water seem a little low, but otherwise it seems correct.

The flow of water is noticeably slower.

Several months into the lease, there was a water leak in the basement and the carpet in the basement had to be replaced.

For a family that uses lots of water it can easily be $1,000/year.