City vs. Survey

[TheNiche]

I'm looking at a survey right now of a residential property on a triangular corner lot in Eastwood where one lot line extends to encompass nearly all of the sidewalks and comes within about one foot of the edge of the pavement. I'm also looking at two images of the lot as far as the City of Houston's PW&E Dept. and HCAD are concerned. Both governmental plats show that the lot is substantially smaller and that each of the lot lines are almost perfectly parallel and within about one foot of the sidewalks.

From the survey, it appears that at some point since 1912, a portion of the lot had extended out into the intersection but was taken by the city in order to build a road. The survey allows for a curved arc that keeps the property behind the edge of the pavement. The City's GIS website shows that the point stopped at the edge of the pavement, but that the lot is still the same general shape.

The title report indicated nothing at all regarding any aspect of the matter.

The survey shows 13,268sf vs. the City/HCAD's record of about 9,709sf.

Screwy, no?

So I have two questions: 1) What happens when the City figures out that it doesn't own land that it thinks that it does? 2) What might trigger the City to look into the matter? Specifically, would an attempt by the owner to replat the lot set them off?