Is it possible to add water pumping wells diagrams to Dia?

[Julio Sergio Santana <ssantana tlaloc imta mx>]

Hi,

Currently I am working in the Mexican Institute for Water Technology. I am
trying to develop a graphical editor to generate diagrams for the 
installation
of water pumping wells. Since I have been using "Dia" to generate 
diagrams for
my documents (UML diagrams mainly), and in order not to start from 
scratch, I
am considering using "Dia" as a starting point.

I know that there is an easy way to define graphical shapes using 
XML/SVG, and
to combine them as sheets (?). However, what I need is the possibility of
introducing and editing textual attributes of the graphical symbols: 
something
similar to the interaction used by UML or ER diagrams, where the box
for introducing symbol properties allows the introduction and edition of
symbol dependent textual attributes. As far as I understand, achieving this
behaviour requires more than just a XML/SVG definition: it requires
programming. Is it possible to add a new set of symbols with this 
behaviour to
the current version of Dia? 

best regards,

Sergio