No, the township does not keep copies of property surveys or plot plans - you need to contact your surveyor. You might also check your title insurance papers to see if a survey is attached.
The only time the township may have a copy is if the house is brand new or work was done within the last couple of years.
Your deed may indicate that a survey was done and who did it. If so, you can contact that surveyor for a copy.
Otherwise, it is up to the property owner to contact a surveyor for a plot plan or survey.