well dear you can read this article, maybe it would help you to get open source maps

http://wiki.openstreetmap.org/wiki/Shapefiles

Hey, thanks for your advice. It will be very helpful, because I'm really not a GIS user, but I'll figure it out. That link you posted, Gabriele, is really good! Thanks again! 

By regulation, there is no open source map. Also drainage system map will never get open source, I believe. That will be locked in the storage of various infrastructure consultants.

Best thing, I suppose, is to use street maps as mentioned before or else by gmaps or whatever and assume that along the street are drainage systems of (by regulation) 25 year return period.

Hey Gerrit - depends what exactly you're looking for: a) drainage network in the sense of water streams, rivers, channels, etc. or b) the sewage system? For a) there's lot of stuff available on global level (Global Drainage Basin Database, HydroSHEDs, NaturalEarth, ...) but I dont know how good this will fit for local level Jakarta... For b) you'd probably have to talk to some city admin officials... But - if you just need something quick for mapping: make screenshots / prints from google maps or open street maps - in the data entry phase you can then swith to the final data that is used for map representation....

Dear Yus, thanks for your answer to my question. By the way, I'm in Jakarta until April 17. Maybe we can meet. It's been a while! 

Hi Harald,

thanks for thinking about this! I was thinking about what you listed under point a), but actually a) and b) are mostly equivalent here in Jakarta.

I  think, I can work with all the resources I have been provided with in the answers and the maps I already had, because my work is really not focused on the mapping. It's just for visualization purposes in regard to some of the issues i touch. 

Greetings to everyone back in Cologne!

Hi Gerrit,

I'm in Amsterdan until June.

In case you need it for presentation, then I agree with Harald Sterly.

I thought it's about publishing an open data.

Good luck

Hi Gerrit

Check it out with local agency those who all should at least provide  you WMS services  of required data set. for publication you should acknowledge them properly.

-Ram

Hi Gerrit,

did you had a look at OSM already? As far as I know, the Humanitatrian OpenStreetMap Project (http://hot.openstreetmap.org), helped to improve the Indonesian and in particular the Jakarta maps of OSM.

Here is a Blog post about flood response in Jakarta facilitating OSM data:

http://hot.openstreetmap.org/updates/2013-01-18_openstreetmap_usage_in_jakarta_flood_response

I can help with getting the OSM data into a GIS..

Cheers,

Christian