GIS - Public Sewer / Water

Very few municipalities have GIS data for there road as-builts, especially for roads which were constructed pre 1980 as they would have been old school paper as-builts. Some municipalities have gone through the effort of digitizing and resurveying to a useable GIS format but are not typically publicly accessible.

In regards to determining where the water runs you would want to look at the neighbors to see if they are on city or well water. If they are on wells then there would not likely be a main on the street.
For sewer again look to see if there is a septic field in front of the neighboring properties.
This information may also be available on water treatment annual reports for water and sewer in your municipality.
You can also look for a storm water drainage study also which may sho you where storm sewers are located.

You should also look for natural gas meters on houses to see if they are serviced and you would need to call the telecommunication companies to see if the high speed internet is available on the nearest poles or buried lines.

from my experience, most larger cities do have databases of utilities and streets in GIS format. unless you are outside of city limits it is likely that the city provides water and sewer service. street and utility plans (whether in paper or GIS format) are generally maintained and can be obtained as a matter of public record. it will require a request and fee to copy the plans or provide the data. usually available at city hall. a call to the city or county is generally the best starting point and probably easier than asking neighbors or lurking around looking for evidence of a leach field

If the government agency is managed properly, the agency will have developed some GIS capabilities as cvg stated.

Here is an example of GIS that is available at one community:

Link

Try doing a websearch on your locality's website for "[locality name] GIS". The results might include what you are looking for.

Most localities - at least on the east coast make at least some use of GIS, and many of them have public access portals.
You can hunt for more obscure GIS portals like this one National Pipeline Mapping System (NPMS) Public Viewer depending on how far you want to carry your search for information.

A well organized GIS portal can look like this one from Washington D. C.